University of Southern California Dissertations and Theses

Comparative evaluation of lighting design software programs for daylighting in buildings

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Comparative evaluation of lighting design software programs for daylighting in buildings

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COMPARATIVE EVALUATION OF LIGHTING DESIGN SOFTWARE PROGRAMS
FOR ANALYSIS OF DAYLIGHTING IN BUILDINGS.

by

V. S. K. Varma. Namburi

A Thesis Presented to the
FACULTY OF THE SCHOOL OF ARCHITECTURE
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
MASTER OF BUILDING SCIENCE

December 2006

Copyright 2006 V. S. K. Varma. Namburi

ii

DEDICATION

To my loving Father, Mother and Family.

iii

ACKNOWLEDGMENTS

This project would not have been possible without the support of many people.
Many thanks to my adviser/chair, Marc Eugene Schiler, for his valuable guidance, his
confidence towards me and his patience to spend his valuable time to read my numerous
revisions and helped make some sense of the confusion without whom this thesis could
not have been successfully completed. Also thanks to my committee members, Douglas
Noble, and Ch.Srinivas, who offered endless guidance and support all through my
education.
Thanks to the University of Southern California Graduate College for awarding
me a Dissertation Completion Fellowship. I am also thankful to my friends who
encouraged me in completing the thesis. Last but not the least I would like to thank my
parents for their immense support and love all through my life who endured this long
process with me.

iv

TABLE OF CONTENTS

Dedication ii
Acknowledgements iii
List of Tables v
List of Figures viii
Abstract xiv
Preface xv
Chapter 1.0: Introduction 1
Chapter 2.0: Background 9
Chapter 3.0: Method 35
Chapter 4.0: Data 49
Chapter 5.0: Tests and Results 54
Chapter 6.0: Conclusions 215
Chapter 7.0: Future work 221
Bibliography 225
Appendices 227
Appendix A Physical units 227
Appendix B Units conversion 229
Appendix C Lighting software cut-sheets 231

v

LIST OF TABLES

Table 1. Evaluation ranking of lighting software programs 21
Table 2. Typical LLD values for typical lamps 42
Table 3. Sorting list of lighting software programs for testing 50
Table 4. Material properties for specularity (artificial lighting) test 63
Table 5. Lamp configuration table for testing specularity (artificial lighting) 64
Table 6. Extracted light level values from workplane grid 69
Table 7. Material properties for specularity (artificial lighting) test 73
Table 8. Lamp configuration table for testing of specularity (artificial lighting) 74
Table 9. Material properties for specularity (artificial lighting) test 79
Table 10. Lamp configuration table for testing of specularity (artificial lighting) 80
Table 11. Material properties for specularity (artificial lighting) test 84
Table 12. Lamp configuration table for testing specularity (artificial lighting) 85
Table 13. Abbreviations used in material properties table for lighting software
programs testing 92

Table 14. Material properties for specularity (natural lighting) test 94
Table 15. Sun configuration table for testing specularity (natural lighting). 95
Table 16. Material properties for specularity test in 3D studio Max-8 104
Table 17. Sun configuration table for testing specularity (natural lighting) in
3D Studio max-8 105

Table 18. Material properties for specularity test in Lightscape 110

vi
Table 19. Sun configuration table for testing specularity in Lightscape 111
Table 20. Simulated output results at 10:00 a.m & 01:00 p.m for new test on
specularity (natural lighting) in Lightscape 125

Table 21. Material properties for specularity test in AGI 126
Table 22. Sun configuration table for testing specularity in AGI 127
Table 23. Typical materials surface properties and estimated illuminance output
from the surfaces 132

Table 24. Material properties for 100% reflectance test in Desktop Radiance 137
Table 25. Material properties for 50% reflectance test in Desktop Radiance 138
Table 26. Material configuration table for reflectance testing in Desktop Radiance 139
Table 27. Test results of 100% reflectance properties for materials in
Desktop Radiance 142

Table 28. Test results of 50% reflectance properties for materials in
Desktop Radiance 144

Table 29. Material properties for 100% reflectance properties of materials in
Lightscape 146

Table 30. Material properties for 50% reflectance properties of materials in
Lightscape 147

Table 31. Material configuration table for reflectance testing in Lightscape 148
Table 32. Comparison of the test – 1 and test – 2 results simulated in Lightscape
for the reflectance test performed 149

Table 33. Material properties for 100% reflectance properties of materials in AGI 153
Table 34. Material properties for 50% reflectance properties of materials in AGI 154
Table 35. Material configuration table for reflectance testing in AGI 155
Table 36. Material properties for 100% material reflectance properties in
3D studio max 160

vii
Table 37. Material properties for 50% material reflectance properties in
3D studio max 161

Table 38. Material properties for 0% material reflectance properties in
3D studio max 162

Table 39. Table of tests for reflectance in 3D studio max 163
Table 40. Material table for 100% transmittance property of wall in AGI 172
Table 41. Material table for 50% transmittance property of wall in AGI 174
Table 42. Test criteria for North wall transmittance in AGI 175
Table 43. Material table for 50% transmittance property of wall in
Desktop Radiance 182

Table 44. Material table for 100% transmittance property of wall in
Desktop Radiance 183

Table 45. Test criteria for North wall transmittance in Desktop Radiance 184
Table 46. Material table for 100% transmittance property of wall in Lightscape 191
Table 47. Material table for 50% transmittance property of wall in Lightscape 192
Table 48. Test criteria for North wall transmittance in Lightscape 193
Table 49. Material table for 100% transmittance property of wall in
3D Studio Max-8 202

Table 50. Material table for 50% transmittance property of wall in
3D Studio Max-8 203

Table 51. Material table for 0% transmittance property of wall in
3D Studio Max-8 205

Table 52. Test criteria for North wall transmittance in 3D Studio Max-8 206
Table 53. Summary of the test results of all four lighting software programs 214
Table 54. Summary of the test results of all four lighting software programs 220

viii

LIST OF FIGURES

Fig.C1.1. Schematic diagram of human eye 3
Fig.C1.2. Deviation of light beam passing through prism 4
Fig.C1.3. Daylight angle variation as per season 8
Fig.C2.1. Right hand thumb rule demonstration of axis 10
Fig.C2.2. Right hand screw rule demonstration of polygon formation 12
Fig.C2.3. Demonstration of backward ray tracing method 13
Fig.C3.1. Illustration of room dimension for cavity method 45
Fig.C3.2. Illustration of cavity method for a room 46
Fig.C5.1. Room plan with fixture layout 56
Fig.C5.2. Luminiare Orientation Diagram 57
Fig.C5.3. Luminiare Tilt Diagram 58
Fig.C5.4. Luminiare Roll Diagram 59
Fig.C5.5. Luminiare Spin Diagram 60
Fig.C5.6. Cross section of test room with light fixtures placement 61
Fig.C5.1.1.1. Illuminance color plot 65
Fig.C5.1.1.2. Tests – 1 result for specularity (artificial lighting) 66
Fig.C5.1.1.3. Iso image and color coded image for luminance 67
Fig.C5.1.1.4. The workplane grid from the desktop radiance simulation 69
Fig.C5.1.1.5. The Winrview image output from the simulation 70

ix
Fig.C5.1.1.6. Back face visibility 71
Fig.C5.1.1.7. Color coded image for luminance 72
Fig.C5.1.2.1. Specularity test simulation results (test-1) in 3D Studio max – 8 75
Fig.C5.1.2.2. Specularity test simulation results (test-2) in 3D Studio max – 8 76
Fig.C5.1.3.1. Specularity test simulation isometric view (test-1) in Lightscape 81
Fig.C5.1.3.2. Specularity test simulation raytrace view (test-1) in Lightscape 82
Fig,C5.1.3.3. Specularity test simulation raytrace image (test-1) in Lightscape &
color coded luminance plot for logarithmic and linear scales 82

Fig.C5.1.4.1. Analysis report of test – 1 in AGI 86
Fig.C5.1.4.2. Raytrace image of test –A in AGI 87
Fig.C5.1.4.3. Window from AGI explaining about specularity 89
Fig.C5.2.1. 3D model of room configuration for natural lighting testing 93
Fig.C5.2.1.1. Building Orientation Process 96
Fig.C5.2.1.2. Specularity test-1 in natural lighting (Desktop Radiance) 97
Fig.C5.2.1.3. Specularity test-2 in natural lighting (Desktop Radiance) 98
Fig,C5.2.1.4. Specularity test showing reflected specular light bounce on the
floor (Desktop Radiance) 98

Fig.C5.2.1.5. Isocontour Plot confirming specula right bounce on floor
(Desktop Radiance) 99

Fig.C5.2.1.6. Window illustrating the camera properties in Desktop Radiance 100
Fig.C5.2.1.7. Window displaying the winrview property in Desktop Radiance 101
Fig.C5.2.1.8. Camera simulation window in Desktop Radiance 102
Fig.C5.2.1.9. Image rendered in Desktop Radiance 103

x
Fig.C5.2.2.1. Image render in 3D Studio max – 8 shows specualartiy test – 1
(natural lighting) 107

Fig.C5.2.2.2. Image render in 3D Studio max – 8 shows specualartiy test – 1
(natural lighting) 107

Fig.C5.2.3.1. Image render in Lightscape shows specularity test – 1 113
Fig.C5.2.3.2. Image render in Lightscape shows specularity test – 1 114
Fig.C5.2.3.3. Color coded illuminiance plot in Lightscape specularity test–2 114
Fig.C5.2.3.4. Color coded illuminance plot in Lightscape linear/logarithmic
scale for specularity test (natural lighting) 115

Fig.C5.2.3.5. Daylight set up parameters windows in Lightscape 117
Fig.C5.2.3.6. Process parameter set up window for quality output in Lightscape 119
Fig.C5.2.3.7. Process parameter set up window for daylight output in Lightscape 120
Fig.C5.2.3.8. Process parameter set up window for finish wizard in Lightscape 120
Fig.C5.2.3.9. Lighting Analysis widow setup parameters in Lightscape 122
Fig.C5.2.3.10. Illuminance plot for Test – 2 (natural ligting) in Lightscape 123
Fig.C5.2.3.11. Rendered image of the exterior space with the Daylight and
sunlight option ON at 10:00 a.m. 125

Fig.C5.2.3.12. Rendered image of the exterior space with the Daylight and
sunlight option ON at 01:00 p.m. 125

Fig.C5.2.3.13. Raytrace image of the exterior space with the Daylight and
sunlight option ON at 10:00 a.m. 125

Fig.C5.2.3.14. Raytrace image of the exterior space with the Daylight and
sunlight option ON at 01:00 p.m 125

Fig.C5.2.3.15. Color coded illuminance plot of the test of exrterior space with
the Daylight and Sunlight option ON at 10:00 a.m. 125

Fig.C5.2.3.16. Color coded illuminance plot of the test of exrterior space with the
Daylight and Sunlight option ON at 01:00 p.m. 125

xi

Fig.C5.2.4.1. Simulated test 1 result in AGI for specularity in natural lighting 128
Fig.C5.2.4.2. Rendered image of test 1 in AGI for specularity concept 129
Fig.C5.2.4.3. Rendered image of test – 2 in AGI for specularity concept 130
Fig.C5.2.4.4. Window from AGI explaining about specularity. 132
Fig.C5.2.4.5. Calculation mode switch window in AGI 134
Fig.C5.3.1. Flow Chart of Photometry and Lighting 136
Fig.C5.3.1.1. Simulation rendered image of test – 1 in Desktop Radiance for
reflectance test-1 140

Fig.C5.3.1.2. Illuminance rendered image for 100% reflective north wall 142
Fig.C5.3.1.3. Luminance rendered image for 100% reflective north wall 142
Fig.C5.3.1.4. Illuminance iso-lumen plot for 100% reflective north wall 142
Fig.C5.3.1.5. Luminance iso-lumen plot for 100% reflective north wall 142
Fig.C5.3.1.6. Illuminance color coded plot for 100% reflective north wall 142
Fig.C5.3.1.7. Luminance color coded plot for 100% reflective north wall 142
Fig.C5.3.1.8 Illuminance rendered image for 50% reflective north wall 144
Fig.C5.3.1.9 Luminance rendered image for 50% reflective north wall 144
Fig.C5.3.1.10 Illuminance iso-lumen plot for 50% reflective north wall 144
Fig.C5.3.1.11 Luminance iso-lumen plot for 50% reflective north wall 144
Fig.C5.3.1.12 Illuminance color coded plot for 50% reflective north wall 144
Fig.C5.3.1.13 Luminance color coded plot for 50% reflective north wall 144
Fig.C5.3.2.1. Photorealistic image for 100% reflective north wall 149

Fig.C5.3.2.2. Photorealistic image for 50% reflective north wall 149

xii

Fig.C5.3.2.3. Illuminance in test-1 for 100% reflective north wall 149

Fig.C5.3.2.4. Illuminance in test-2 for 50% reflective north wall 149

Fig.C5.3.2.5. Luminance in test-1 for 100% reflective north wall 149

Fig.C5.3.2.6. Luminance in test-2 for 50% reflective north wall 149

Fig.C5.3.2.7. Material properties assigning window in Lightscape 150
Fig.C5.3.2.8. Lighting analysis output window for test – 1 in Lightscape 151
Fig.C5.3.2.9. Lighting analysis output window for test – 2 in Lightscape 152
Fig.C5.3.3.1. Illuminance output in AGI for test-1 for 100% wall reflectance test 156
Fig.C5.3.3.2. Illuminance output in AGI for test-2 for 50% wall reflectance test. 157
Fig.C5.3.3.3. Exitance output for test-1 in AGI for100% wall reflectance test 158
Fig.C5.3.3.4. Exitance output for test-2 in AGI for 50% wall reflectance test 159
Fig.C5.3.4.1. Illuminance output for test-1 in 3D studio max for reflectance test 164
FigC5.3.4.2. Luminance output for test-1 in 3D studio max for reflectance test 165
.Fig.C5.3.4.3. Illuminance output for test-2 in 3D studio max for reflectance test 166
Fig.C5.3.4.4. Luminance output for test-2 in 3D studio max for reflectance test. 167
Fig.C5.3.4.5. Illuminance output for test-3 in 3D studio max for reflectance test 168
Fig.C5.3.4.6. Luminance output for test-3 in 3D studio max for reflectance test. 169
Fig.C5.4.1. Room plan with fixture layout and labeling. 171
Fig.C5.4.2. Room cross section - AA` with fixture layout and labeling. 171
Fig.C5.4.1.1. Transmittance test for 100% transitivity property 176
Fig.C5.4.1.2. Transmittance test for 50% transitivity property 177
Fig.C5.4.1.3. Transmittance test for 100% transitivity property by a professional 178

xiii
Fig.C5.4.1.4. Transmittance test for 50% transitivity property by a professional 181
Fig.C5.4.2.1. Simulation model for the transparency test in Desktop Radiance 185
Fig.C5.4.2.2. Winrview window for transparency test in Desktop Radiance 186
Fig.C5.4.2.3. Test-1 on wall-A for 100% wall transparency 187
Fig.C5.4.2.4. Test-1 on wall-B for 100% wall transparency 188
Fig.C5.4.2.5. Test-2 on wall-A for 50% wall transparency 189
Fig.C5.4.2.6. Test-2 on wall-B for 50% wall transparency 190
Fig.C5.4.3.1. Test-1 on wall-A for 0% wall transparency in Lightscape 195
Fig.C5.4.3.2. Test-1 on wall-B for 0% wall transparency in Lightscape. 196
Fig.C5.4.3.3. Test-1 on wall-B for 0% wall transparency in Lightscape. 197
Fig.C5.4.3.4. Test-1 on wall-A for 100% wall transparency in Lightscape. 198
Fig.C5.4.3.5. Test-1 on wall-B for 100% wall transparency in Lightscape 199
Fig.C5.4.3.6. Test-2 on wall-A for 50% wall transparency in Lightscape 200
Fig.C5.4.3.7. Test-2 on wall-B for 50% wall transparency in Lightscape 201
Fig.C5.4.4.1. Test-1 for 100% wall transparency in 3D studio max-7 207
Fig.C5.4.4.2. Test-1 for 100% wall transparency in 3D studio max-7 208
Fig.C5.4.4.3. Test-2 for 50% wall transparency in 3D studio max-7 209
Fig.C5.4.4.4. Test-2 for 50% wall transparency in 3D studio max-7. 210
Fig.C5.4.4.5. Test-0 for 0% wall transparency in 3D studio max-7 212
Fig.C5.4.4.6. Test-0 for 0% wall transparency in 3D studio max-7. 213

xiv

ABSTRACT

This thesis outlines an approach to compare the various most commonly used
daylighting/ lighting design software programs available in the market and evaluate their
performances based upon their capabilities to fulfill the assigned tasks by the
users/lighting designers. The most widely available and commonly used potentially
powerful lighting software programs for quantitative and qualitative daylight
performance will be evaluated by assigning some test on various lighting concepts. A
summary chart and the detailed evaluation procedures performed is to be created to guide
the users and emphasize the available features and accuracy of the software for
Architectural daylighting. These tests will bring to light the hidden bugs within these
lighting software programs and will help users, cautioning them of the possible data
errors while performing the analysis of their project jobs using these lighting design
software programs. Physical models or base case real buildings may be used depending
upon the requirements and time to analyze the accuracy of the final outputs of the
computer software program generated models.

xv

PREFACE

With the rise of computer simulations, designers are able to estimate the interior
and the exterior illumination levels, glare, potential energy impact of daylighting, etc
with great ease in less time using lighting design software programs. Architects are able
to design artificial lighting in accordance to the daylighting. For large scale project
buildings the physical model becomes very difficult and time consuming, but by
introducing the new generation of computer software programs, designers are able to
perform the analysis at much cheaper and faster rates, with good accuracy in prediction
of daylight in buildings and its surroundings.
This thesis compares the various most commonly used daylighting/ lighting
design software programs available in the market and evaluates their performance based
upon their capabilities to fulfill the tasks assigned by the users/lighting designers. The
most widely available and commonly used which are potentially powerful software
programs for quantitative and qualitative daylight performance will be evaluated by
assigning a few tests on various lighting concepts. The sequence of tests will start from
the very basic concepts of lighting and will lead to further more detailed and specific tests
for various conditions depending on their range of accuracy. A summary chart of the
detailed evaluation procedures performed will be created to guide the users to perform
any further tests. This report generated should be able to emphasize the available features
and accuracy of the tested lighting software programs for Architectural daylighting.

xvi
These tests will cast light on hidden bugs within these lighting software programs
and will be helpful for the users providing a note of caution of the possible errors while
performing the analysis on their project jobs using these lighting design software
programs. If required, physical models may be used to analyze the accuracy of final
outputs of the computer software program generated models. A base case of real building
field measurements may also be used to evaluate the software’s performance in real life
case depending upon the requirements and the time criteria of study.
This thesis will outline the qualities and capabilities of few lighting software
programs for daylighting in buildings and environment. The analysis and evaluation will
be performed on Windows operating PCs, to narrow down the complexity of the work for
the schedule time criteria. Some large architectural design firms have developed their
own lighting software programs for their personal use. Most of the lighting software
programs for commercial use and a few from research organizations are selected for the
study and only 3 to 4 top priority software programs highly used in United States are
evaluated and analyzed. The analysis is performed to help guide an amateur user to know
all about available features and drawbacks in various lighting softwares.
Most of the lighting software programs do a great job by integrating the geometric
simulation with the analysis, which can satisfy the demands of the designer/architect. I
intend that this thesis should uncover the aspects of availability, cost, and ease of
learning/ using, input requirements, time, accuracy, final outputs…etc. This thesis may
not be able to cover the lighting software programs in sufficient depth to know all its
components and capabilities. This thesis will look in depth at some issues of interest to
everyone, but will necessarily not cover all possible issues.

1
CHAPTER- 1
INTRODUCTION TO LIGHT
Light is a form of radiant energy, which stimulates our sense of vision. The sense
of vision is one of the most important senses for most living creatures which enable them
to know the objects surrounding them in their environment. A luminous source such as a
candle sends out light. In the absence of light, it’s not possible for the eye to function and
perceive objects. When light is incident on a non-luminous object, part of it is scattered.
This scattered light from the object enters the eye and enables it to identify the object.
Some self luminous sources, such as an electric lamp, or a burning candle, not only make
themselves visible by the light they radiate, but also make the non luminous objects
visible.
The light propagation takes place both in the form of waves and in the form of
quanta. The wave theory of light can explain the interference, diffraction, and
polarization of light whereas the quanta or photon theory was successful in explaining the
concepts of Compton effect, Photo-electric emission etc. thus light has a dual character,
namely that of a wave and that of a particle.
Some of the facts about light and its propagation through medium are:
• No material medium is required for light propagation.
• The velocity of light in air/vacuum is 3 x 10
8
ms
-1

• The speed of light decreases as it passes through a denser medium.
• Light incident on a surface can be absorbed, transmitted or reflected.
• The energy is carried in light waves.

2

Daylight plays a very crucial role in human survival. It is being utilized in all
aspects of life. Daylight sustains life and provides richness to the sense of vision. In some
cases daylight is also termed as natural light. Plants use natural light for the process of
photosynthesis in the presence of air, chlorophyll and water to produce energy which
feeds life and recycles the air. Natural light provides the true richness of color for humans
to perceive the entire color range. The eye is stimulated by light reflected from objects,
thus light is a prerequisite of vision. In the human eye, the pupil functions as a light
limiting device to protect the rods and the cones and the lens functions as a convex lens
with in the eye. The rays from the object get focused on the retina in the eye. The image
in the retina is converted by rods and cones into signals and is transferred by the optic
nerve to deliver the information to the brain, so as to enable the person to identify the
object and process the information.
The functionality of the eye generally depends upon the distance of the object and
the angle which the object subtends at the eye. This angle is called visual angle. The
apparent size of an object depends on the visual angle. The greater the distance of the
object the smaller this angle, hence the smaller the apparent size of the object or vice
versa. If the object is placed less then the minimum distance of 25cm from the eye, it can
cause strain on the eye. This focal distance for a person with nominal vision (without
spectacles) is called as the ‘Least distance of distinct vision’. The nearest point at which
the object can be seen without any strain is called the near point and the point at the
greatest distance at which an object can be seen without any strain is called the far point.
The distance between the far point and the near point is known as ‘range of vision’.

3

Fig.C1.1: Schematic diagram of a human eye
1
.

1
http://en.wikipedia.org/wiki/Image:Schematic_diagram_of_the_human_eye_with_
English_annotations.svg. (Downloaded: Aug 10, 2006).

4

Poor lighting can cause eyestrain, fatigue, headaches and irritability. The human
eye can adapt very effectively over a large range of light levels from 100,000 lux
(daylight) to 0.1 lux (moonlight) a one million to one ratio. But this adaptability is
constrained by the time required to adjust from high light levels to low light levels. The
eye can adapt comfortably with a ratio of 200:1 when moving from bright outdoor
environment to indoor artificially lit spaces. It takes about 15 minutes to fully adapt to the
first 100: 1 light level drop. 70% of the light level adjustment can be made in the first 90
seconds. This time lag explains the reason for the cause of temporary blindness when
moving from a less lit or dark space to a brightly lit space. This strain on the eye causing
discomfort in vision can be called glare which can be witnessed when looking at the
direct sun or a highly specular surface in the direct sunlight.

Fig.C1.2: Deviation of light beam passing through prism

5

When a ray of light passes through any refracting medium, there is a change in the
direction of the path of light. The angle between the incident ray and the emergent ray is
called the angle of deviation, ‘d’. A ray of white light passing through the prism splits
into 7 different colored rays. This property of splitting composite light into its constituent
colors is called dispersion which takes place due to the refractive index of the material
through which the light ray is passing and the fact that different wavelengths refract at
different rates. This property of light dispersion is primarily used in the design of
chandeliers and decorative fixtures for the antique-lighting design.
In architecture light can be broadly classified as natural light (daylight) and
artificial light. Artificial lighting plays an equally important role in the human life as that
of natural lighting. It can reach places where daylight cannot. It is also functional at
night. Electric light was first produced by Thomas Alva Edison when the electric current
was allowed to flow through a thin coil called the filament in an incandescent bulb. When
the filament of incandescent lamp is heated to a very high temperature of 2000 °C due to
the resistance in the coil, it turns red, yellow or white hot which emitted visible light.
Most of the incandescent bulbs have a filament made up with tungsten metal. The glass
bulb is filled with an inert gas to avoid the oxidation of the filament and to prolong lamp
life. The bulbs are very compact in size and ease to use. Incandescent light consumes a
lot of energy and most of the energy consumed is converted to heat as the efficiency of
the early incandescent light bulbs was very low. The amount of light produced when
compared to the amount of heat generated is very low and hence the efficiency is always
a major factor for consideration even up to now.

6
The 97% of the energy supplied to the incandescent bulb is radiated as heat which
in turn can hike air-conditioner loads. Artificial lighting is independent of location,
climate, and the building fabric, where as the daylighting strongly depends on external
conditions and the climatic factors. On an average most of the world relies on artificial
incandescent source. Though fluorescent is more efficient than incandescent in terms of
energy, in the past fluorescent was less used due to the low CRI. The present day research
has developed many fluorescent types that have excellent color rendering qualities. Thus
because of their efficacy and extended lamp life, they are replacing incandescent sources.
Despite low efficiency and cost of artificial lighting compared to natural lighting,
it has a major role being played in most of the building types such as the cinema theaters,
museums, night recreational centers, residential lighting, street and community lighting,
etc. The daylighting can be used effectively in most of the semi open places, but deep
enclosed places rely mostly upon the artificial light source. The better integration of
artificial and daylighting features in lighting software programs will help designers and
architects to use them effectively during their design analysis stage and application. This
can also help in reducing the peak energy loads of the buildings and allow the process to
work effectively and efficiently with in the building spaces.
The great importance of daylighting was felt during the 1970’s energy crisis
together with the recognition of the damage caused to the environment. Working in an
artificial environment under artificial lighting without any interaction to the outdoor
environment has resulted into various psychological problems, SAD (Seasonal Affective
Disorder) and Sick Building Syndrome. Artificial lighting cannot completely remove the
claustrophobia for which the presence of natural light helps significantly.

7

There are many case studies being performed to identify the possible relationship
between productivity and daylight in the work space. Most of the results prove that the
well lit and daylit spaces have higher productivity. People in such work spaces express
their opinion desiring to have some visual contact with the outdoor environment.
Human beings are mostly adapted to daylight with which we measure all other
kinds of light. This is the source in which we view materials and our environment and
establish the relationship of their appearance. Most ancient buildings show large
dependency on natural lighting. Daylight when compared to artificial lighting can render
better health, and energy savings. It is eco friendly. The color appearance of any object
in our surroundings primarily depends upon the spectral composition of the light and we
consider the daylight as the norm by which we classify the color rendering parameters of
other light sources. One measure of how well light will actually show true colors is called
the color rendering index. This is a parameter to identify if all of the colors are properly
rendered by the light from the source. It helps to determine if there are any missing
wavelengths in the light source. It compares the light from a source at a given color
temperature with the light from an incandescent source at the same temperature, or with
natural light, in the color temperatures.
The present available software programs for lighting mainly deal with the prime
factors of artificial lighting, but consider very little about daylighting. There are a few
software programs which have embedded the daylighting calculations along with
artificial lighting but rarely explore the other secondary concepts of daylighting as
mentioned above.

8

The daylighting play in some of the lighting software programs is very limited.
The concepts like rainy day analysis, glare rating, specularity, light dispersion, design for
elderly people etc, are still to be incorporated. These lighting issues are considered not
very crucial in the design of the lighting software program starting from scratch. All the
existing artificial lighting software programs under the development stage should include
and introduce new lighting features which can help in the better output.

Fig.C1.3: Daylight angle variation as per season.

9
CHAPTER – 2.0

BACKGROUND STUDY
Light is a form of radiant energy, which simulates our sense of vision. The light
incident on a non-luminous object scatters it partly. This scattered light from the object
enters our eyes and enables us to identify the objects. The light from some of the
luminous sources are intense enough to make the non-luminous objects visible.
According to Newton’s corpuscular theory a luminous source sends out a number of tiny
particles called corpuscles, which travel along the straight lines with a speed of about
3x10
8
ms
-1
. This theory could successfully explain the phenomena like reflection of light
and refraction of light etc.
The other theory called as Huygen’s wave theory put forward by Huygen and
developed by Thomas Young and Jean Augustine Fresnel considers the molecule and
atoms of the source of light to be in a state of vibration. The energy of vibrations of these
molecules and atoms is communicated from particle to particle in surrounding medium
and this gives rise to the propagation of a periodic disturbance in the medium. Thus light
energy is propagated as wave motion. The main advantage of this theory was that it could
successfully interpret various phenomena like reflection, refraction, interference,
diffraction and polarization of light. The main disadvantage is that it does not explain
light in a vacuum. The above two theories in short explains about the dualistic nature of
light, which behaves both as the particles (photons) and waves. Thus a ray is a line along
the path of light propagation which gives us the path taken by the light. One of the major
obstacles in 3D computer rendering of scenes includes the elimination of hidden surface,
which are not visible to the eye of the viewer.

10

The Z border method assigns color for pixel variation as the depth varies. A ray of
light travels the path from the eye of the viewer to a point on view plane. The distance
required by the ray to travel from surface to surface is calculated and the shortest distance
calculated is considered as the visible surface and all other surfaces behind them as the
invisible surfaces. Hence raycasting is called a hidden surface removal method. This
technique could be employed for rendering volume data.
The basic rule of thumb to understand the right hand Cartesian coordinate system
is explained for the better understanding of how most of the lighting design software
programs work in reality. Stretch the thumb, the fore finger and the middle finger of the
right hand mutually perpendicular to one another as shown in the image below. If the
thumb represents the direction of X-axis, then the index finger represents the direction of
Y-axis and middle finger pointing upwards is Z-axis.

C2.1: Right hand thumb rule demonstration of axis

11
This right-hand Cartesian coordinate system is very useful to work on CAD as
most of the present day software programs are designed on this concept which deals with
2D and 3D modeling. Like the Right hand thumb rule, there is another similar Cartesian
coordinate system called Left hand thumb rule which is also similar to this concept and is
often used in physics (magnetism) and electronics. To explain this concept in brief,
extend the thumb and first two fingers of the left hand, so as to be mutually perpendicular
to each other. The first finger (index finger) gives the direction of X axis, middle finger
points the direction of Y-axis and the thumb shows the direction of Z-axis
One may also be familiar with another concept in computer graphical applications
for determining the normal vector of polygons. In this method the direction of the normal
vector is considered to be in the direction of the screw driving in when we rotate the
screw head in clockwise direction. Rotating the screw in anticlockwise direction to
remove it from a surface will make the screw to move in the direction away from the
surface to which it is drilled. Hence it represents that in computer graphic applications,
going anticlockwise for a polygon vertices will have its normal vector in a direction
facing towards us and going clockwise will have its normal vector in a direction facing
away from us.
The other way of explaining this is to hold the right hand as shown and the thumb
represents the direction of the normal vector of the polygon and the folded fingers
represent the sequential direction of the formation of the polygon vertices. This is clearly
demonstrated in the image which shows the direction of the normal vector as the
direction of the thumb for a pentagon (polygon) formed.

12

C2.2: Right hand screw rule demonstration of polygon formation
The two very common terms often spoken in the lighting design software
programs are the Radiosity and Raytracing.
Radiosity method: This method also called the radiant flux transfer method is a
computer graphic method primarily used for calculating the diffuse and reflected light
distribution. It is very easy to compute the small spaces using the radiosity method with
out much concerned about the surface reflectance (indirect light) from surfaces adjacent.
This method is direction independent of the viewer. Multi-reflections like the specular
surface reflections are very difficult to simulate in this method. This method is often used
for simulating lighting of the global illumination model.
Raytracing method: This method produces 3D virtual views graphically in
computers, evolved from raycasting technique which is also known as common hidden
surface removal method. Raytracing technique calculates illumination on a surface by
tacking/tracing the path of a light ray undergoing multiple reflections off surfaces.

13
This method is classified into two types:
1. Forward raytracing.
2. Backward raytracing.

Forward Raytracing:
In the forward raytracing technique, the ray of light starts from the light source
and travels in defined fixed direction. Upon the intersection of surface, the ray splits into
reflected and refracted directions. These rays carry color with them depending upon the
properties of the materials assigned by the user. In the whole operation, only a few set of
light reflections /refractions will be successful enough to reach the eye of the viewer and
the rest of them are lost to the environment. The final series of intersected surfaces are
assigned colors depending upon the value of distance traveled.

C2.3: Demonstration of backward ray tracing method

14

Backward Raytracing:
The backward raytracing method is based upon the principle that a path of light
ray is fixed considering that the reflections and refractions follow a path in the same
direction or opposite to each other. This method follows the light way in the backward
direction from the eye of the user to the light source. This is a more efficient technique
compared to forward raytracing as only the required rays travel backward from the eye.
Stochastic Raytracing: One of the powerful tools evolved for dealing the global
illumination model is the stochastic rendering which simulates the diffuse light
distribution and reflections. This tool is considered being used in Radiance software
program.

Distributed Raytracing:
This method is very effective for cases having multiple light source simulations
for radiosity solutions. The exterior environment simulation in a real case is an example.
It is very important to have a proper understanding on these definitions as we very
frequently come across them when speaking about the lighting software programs and
their integral parameters. During the stages of rendering, sometimes to receive a
photorealistic image of the model we have to perform the operation of raytracing after
performing radiosity. Most of the specular surfaces are not photorealistic after we
perform the radiosity and hence raytracing has to be performed to see the desired outputs.

15

PREVIOUS RESEARCH PAPERS AS BACKGROUND STUDY

Others have published research papers on daylighting design software programs
and their evaluation based upon certain specific criteria. This chapter will outline the
testing procedure followed in some of these papers, the research outputs of the tests and
their conclusions. Some of the research papers were inclined towards the energy
calculations and some towards the user friendliness of the simulations software programs
for daylighting. We will outline and evaluate some of the available papers and discuss in
brief their findings. Most of this chapter is in the words of the author of these research
papers published by them and the conclusions are solely their opinion on the final output
results they came upon during their study.

RESEARCH PAPER-1
Mr.Amarpreet Sethi
2
from the college of architecture and environmental design of
Arizona State University published a paper on a study of daylighting techniques and their
energy implications using designer friendly simulation software. The whole abstract of
the paper is about the integration of building design with the daylighting strategies.
ECOTECT was the software program being used in his research, which evaluates both the
energy and daylighting simulations.

2
Amarpreet Sethi, “A study of daylighting techniques and their energy implications using a
designer friendly simulation software”. College of Architecture and Environmental Design,
Arizona State University, P.O Box 871905

16
More than energy conservation, it is occupant satisfaction which Amarpreet
considers more important. The paper considers daylight distribution in rooms as non
uniform emphases the importance of reflected and diffuse light within the space.
This is for the uniformity of light distribution to avoid any possible glare causing
discomfort for the occupants. In his publication, he considers Ecotect having the
capability to do both the solar analysis and daylighting calculations. It is mentioned in his
paper that Ecotect uses the BRE Daylight Factor method for daylight calculation and a
point to point method for electric lighting. The BRE Daylight Factor method ignores
direct sunlight contributions.
In his testing, he modeled a room of 35’ X 24’ X 10’ with a workplane height of
2.5ft having a variable sill height and orientation for different cases. The wall and the
ceiling were painted light grey and the specularity of the light shelf as 0.2(white) –
0.95(mirror) for the location of Phoenix on 23
rd
June and 24
th
September. The glazing
was lintel at ceiling height.
To make it a point of consideration, this was a good case for testing the
specularity in daylighting for the evaluation of lighting performance of the software
program. Various cases were tested by him for light-shelves using Ecotect believing it to
be performing accurately. Hence this program was used as a tool to test a case and no
tests were performed to evaluate the accuracy of this software program. This brings to the
conclusion of presuming that this software program (Ecotect) is performing the lighting
and energy analysis to be very accurate and precise.

17
Here Amarpreet, S concludes that “[t]he simulation software used [Ecotect], has
the ability to simulate daylighting and solar exposure, insolation and further may be used
in other areas of thermal, acoustic, lighting analysis etc”
3
. Of course, this is entirely
incorrect as insolation is not considered in the daylighting calculations of Ecotect.
This was discovered by Evdoxia Giovanopolou at USC in her thesis and verified
by Andrew Marsh of Ecotect. Amarpreets conclusions contain analysis of solar gain due
to the reflective property of daylighting technique. There was not much explained about
the testing of accuracy of this lighting software program other then the tests performed
using this software program for light-shelves.

Comments from the author of this thesis:
Mr.Amarpreet Sethi was using Ecotect software program more as a tool for
analyzing daylighting. The tests performed are not intended to test the accuracy of the
software program but is rather oriented towards the light-shelves testing. The testing
procedure gives us a good idea of how to perform the case platform for testing a
parameter. This procedure when used for testing the software program making the base
case of a space a fixed model can help in organizing a sequential working procedure for
the tests. On an overall, this software program as explained by Sethi is more inclined
towards energy calculations and analysis than lighting. Hence one may not be willing to
call this solely as an independent lighting design software program.

3
Amarpreet, S. Conclusions on the lighting software program (Ecotect). “A study of daylighting
techniques and their energy implications using designer friendly simulation software”(2003: 5).
Available online: http://www.sbse.org/awards/docs/2003/Sehti.pdf. (Downloaded: Aug 10, 2006).

18
RESEARCH PAPER-2
The second paper used as the background for the thesis is on “Daylighting
Simulation: Comparison of Softwares for Architect’s Utilization” by Christakou,
Dimitrios Evangelos, Amorim, Claudia Naves David from Universidade de Brasilia
4
.
The four daylighting software programs: Desktop Radiance, Rayfront, Relux
2004 Vision and Lightscape were analyzed to explore their complexities, software
interface and the levels of hard interpretation of the results for the professional practice of
the architects. The objective of the study was to find the advantages, limits and
drawbacks of each software program and the results were intended to help in the software
improvement within the perspective of interface and help manuals.
The evaluation was performed considering the criteria like user interface,
geometry, output, daylighting parameters, materials description, processing, validation
and user support. Radiosity and raytracing are the two different methods being used at
present for the lighting simulation and evaluation. The four softwares were selected on
the basis of the availability in the LACAM (Laboratorio de Controle Ambiental) in the
post-graduation program in Brasilia. A model was generated in AutoCAD R14 with
specific room dimensions and material properties of the surfaces. Relux 2004 pro+vision
doesn’t import 3d models was the exception in the tests. The location and altitude with
sky conditions were maintained the same for all the cases. The four software programs
available at LACAM (Laboratory of Ambient Control) include Lightscape, Desktop
Radiance, Rayfront and Relux 2004 vision were selected and analyzed.

4
Christakou, Dimitrios Evangelos, Amorim, Claudia Naves David, “Daylighting Simulation:
Comparison of Softwares for Architect’s Utilization”.
Programma de Pos-Graduacao da Faculdade de Arquitectura e Urbanismo, Universidade de
Brasilia-Brasilia, D.F.Brasil .(vangelis@unb.br, elamormin@unb.br)

19
The criteria was based upon the flexibility of use by an architect, state of the art
algorithms, precision of the data, possibility of access from a Brazilian architect. The
eight point evaluation criteria was based upon modeling-input of geometry, user
interface, output, daylighting parameters inputs, optical properties of the surfaces,
processing –efficiency if simulations, validation- precision of outputs, support to the user.
There is no indication of the testing procedure followed nor the detailed test results, but
only a final conclusion was presented. According to the final conclusion, they gave Relux
vision 78 points, Lightscape with 60 points, Desktop Radiance with 23 points and
Rayfront with 17 points.
Lightscape: They say that this program produces good photorealistic images and
is good for presentations considering its animations and VRML resources. They consider
that the programming problems can’t be rectified due to no more in production of this
software program. According to them the full strength of this program lies in the interface
and weakness lies in daylighting parameters matrix.
Desktop Radiance: They say that this program attaches itself to AutoCAD as a
plug-in which helps design integration with simulations. Precision level adjustment is
possible along with both time and weather conditions. Restricted user interaction
interface is a drawback and the program algorithm need more precise and accurate input
information and complex adjustments.
Rayfront: They consider using this software program along with 3D SOLAR has
great strength for the designing process by the architects. It is pointed out by them in their
paper that Rayfront alone cannot satisfy all the need of the design though is a good tool
for research application.

20
It states, “[a]ll the potential of the RAYFRONT is shown when it is running
associated with the 3DSOLAR and the addition of plug-in RAYDIRECT. It becomes
ideal tool to analyze the advanced daylighting devices
5
”. They consider that the
drawback lies in its poor performance of the interface.
Relux 2004 Vision: They consider that the good user interface of this software
program makes it an appropriate program for architects. It has been mentioned that this
program contains a strong internal modeler, efficient enough to work on different design
geometry. They explained that this program being potent enough to directly generate 3D
entity objects without the help of initial lines and curves and also for its potential to
evaluate some of the energy and lighting factors such as glare, annual energy utilization,
color coding and iso-contours of illuminance/luminance of 3D models. They said that this
program can support the design working of architects with qualitative and quantitative
lighting analysis grading this as a very user friendly lighting software program for the
architects and designers.
The final conclusions of the paper say that, “[a]mong the softwares analyzed,
Relux Pro 2004 + Vision is the most adequate for architect’s use; RAYFRONT and
DESKTOP RADIANCE presented more difficulties to be used in the design process….
Lightscape has the user friendly interface, but not as intuitive as Relux
6
”. Desktop
Radiance integrates as a plug-in with AutoCAD.

5
Christakou et al., Discussion on Rayfront. “Daylighting simulation: Comparison of softwares
for architects utilization” pg-4

6
Christakou et al., Conclusion on software programs selected. “Daylighting simulation:
Comparison of softwares for architects utilization” pg-4.

21
The main menu tab in Desktop Radiance (AutoCAD) is comfortable to use similar
to the working process of AutoCAD. The author of this paper specifically mentioned that
“[s]ome aspects of the lacks of precision of the calculations [Lightscape] are mainly
related to the sky models and the absence to treatment of the specular surfaces in the
optical properties of the materials
7
”, which I would contradict partially. Some of the tests
performed by me on Lightscape in chapters-5 will show the treatment of the specular
surfaces in the optical properties of the materials. No production/ development is a big
setback for Lightscape. It is specified by Christakou et al, that Relux vision has a very
reasonable light calculation precision, correct interface, user-friendly and extremely
simple and provides easy learning where as Rayfront and Desktop Radiance have high
potential for the evaluation of the daylight.
They believe that the methodology adopted for evaluation of software showed is
adequate, hence concludes that for present the ideal software of lighting simulation
doesn’t exist. They consider a combination of editing and modeling tools for the
daylighting simulation software program will make it a perfect program.
Table-1: Evaluation ranking of lighting software programs according to Christakou et al.

Lightscape Desktop
Radiance
Rayfront Relux
Vision
1. Modeling input of geometry 5 6 3 3
2-User interface 38 -2 -10 62
3-output 8 9 12 3
4-Daylighting Parameters 0 1 6 1
5-Optical properties of surfaces 4 4 4 4
6-Processing-effeciency if simulations 2 -1 -1 -1
7-Validation 2 2 2 2
8-Support to the user 1 4 1 4
Total 60 23 17 78

7
Christakou et al., Conclusion on Lightscape. “Daylighting simulation: Comparison of softwares
for architects utilization” pg-4

22

Comments from the author of this thesis:
The software programs selected were limited to the availability at LACAM
(Laboratory of Ambient Control) in the university. The good aspect of the paper is its
orientation for helping the architects and designers in selected the appropriate software
program for the task present. Most of the software properties and the various criteria
focused are more of surface brushing which speaks about something of not that important
if the basic responsibility of the software is not performed. No details nor the testing
procedures were explained due to which one can’t make a clear conclusion about the
software program’s real capabilities. Emphasis is more on secondary issues and most of
the primary issues like illumination, reflectance, specularity, etc were not covered.
The comments on Lightscape, “ Lack of calculation precision for the sky models
and non availability of the treatment of specular surfaces in optical properties of materials
and no production/ development is a big setback for Lightscape
8
” is not completely true.
The specular surface properties of materials can be assigned through the material
properties window. In one of the research paper on Walt Disney Concert hall by
Prof.Marc.Schiler from University of Southern California, was using the Lightscape
software program for the glare analysis which had brushed steel and specular steel
surfaces to be analyzed. This will contradict the statement of author’s (Christakou et al).
about his conclusion about specularity using the following lighting software programs as
specified by him.

8
Christakou et al., Conclusion on Lightscape. “Daylighting simulation: Comparison of softwares
for architects utilization” pg-4

23

RESEARCH PAPER – 3
The third paper referred for the background of my thesis is “Lighting/Daylighting
Analysis: A Comparison” by Harvey Bryan, Sayyed Mohammed Autif from School of
Architecture, Arizona State University, Tempe
9
. They wanted to explore both the
advantages and disadvantages of several simulation programs. They made efforts to point
out the efficacy of the various daylighting software programs and have expresses that the
present day rendering software programs can produce realistic images but lack in
accuracy of qualitative and quantitative lighting concepts and values.
The present day techniques to analyze the interior illumination of spaces include
the physical models, computer graphics and analysis. The whole light calculation system
can be as simple as the simplified light calculations or can be very detailed and accurate
as of the computer analyzed calculations. The first generation light calculation programs
were based on lumen method also called as coefficient of utilization method where as the
next successors started using CIE (Commission Internationale de l'Eclairage) sky
luminance technique. The author of this paper specifies that. Microlite is a powerful but
simple program using CIE sky luminance technique, but certainly lacks in accuracy while
using the split flux method for calculating reflected components. On the other hand the
introduction of Lumen II was able to surpass successfully the reflected component issues
of the Microlite though still has the problem of mainframe platform for its full-scale use.

9
Harvey Bryan, Sayyed Mohammed Autif, “Lighting/Daylighting Analysis: A Comparision”
School of Architecture, Arizona State Univeristy, Tempe, AZ. 85287-1605.
harvey.bryan@asu.edu, smautif@hotmail.com, (Downloaded: Aug 10, 2006).

24

Introduction of Superlite was successful to over-come the challenge of the L & U-
shaped building profile. Radiance was evolved in 1980s which was a powerful tool
capable enough to integrate graphics with radiosity. The shift from mainframe to the
present desktop PCs gave birth to Desktop Radiance which turned convenience to a new
horizon for general users. Adeline was brought into existence in 1990s which is also a
powerful lighting software program.
The four lighting software programs that have been chosen by Harvey.B et al, for
the investigation in their study are:
1. Lightscape 3.2
2. Desktop Radiance 1.02
3. Lumen Micro 2000.
4. FormZ RadioZity 3.80.

According to their study and understanding on these four software programs:
• Lightscape, a powerful daylighting software program is expected to be an
integral component of Autodesk VIZ4 in the future.
• Desktop Radiance, a windows operating system based AutoCAD plug-in
contains a good library with-in integrated.
• Lumen Micro, the next generation of Lumen II supports complete lighting
analysis of both indoor and outdoor.
• FormZ Radiosity from FormZ uses radiosity based rendering for the lighting
analysis.

25

The criteria followed by them to compare the above four lighting software
programs include modeling and input, daylighting setup, surface properties,
simulating/rendering output, user interface, online help etc.

Lightscape:
Modeling & Input: The capability to import various file format extensions and the
ability of the software program to understand surface orientation and normal is quite
impressive.

Daylight set up: The sky conditions are well organized and easy to use.
Geographical positioning can be made with respect to altitude and azimuth further
defined by time, date and month of the year. The author of this research paper makes a
statement that some “tests [performed] with the program showed that it does not use an
accurate clear sky model
10
”.
The test was to check the Iso-lumen contour illuminance graph in a room with a
south facing window when the sun is due east under the clear sky conditions. They found
that the plot for Lightscape was very uniform as if the sun was placed exactly
perpendicular to the window (but the sun is due east). The Lumen Micro program shows
it correctly which was compared to the Lightscape to show the range of error.

10
Bryan.H et al,. Comments on Daylighting Setup program (Lightscape). “Lighting/Daylighting
Analysis: A Comparision”. Available online: http:// www.sbse.org/awards/docs/Autif.pdf .
(Downloaded: Aug 10, 2006).

26

Surface properties: Lightscape has a material library included and the material
properties can be modified as preferred accordingly. The procedural textures generated
can be applied onto the surfaces. The warning message often keeps a check on errors,
intimating the users.

Simulating/ Rendering: Lightscape uses the radiosity technique for calculation and
raytracing for final rendered images. The mesh density can be adjusted accordingly to
calculate the radiosity. Some time the light leaks are found in the output images of the
model even under the high accuracy radio button tab which is a point of real concern.

Output: Lightscape has the capability to generate pseudo color images, point by
point illuminance/ luminance with a summary of light values (min, average, max,
min/ave, min/max etc.) of the surfaces. The major drawback is its incapability to save the
final pseudo color images etc for the user for his further use though has the availability to
save them in various file format extensions.

User interface: Wizards help the amateur users for setting up the simulations.
There are also the chances where the user may-not notice some of the simulation settings
like the surface normal orientation procedure. The restriction on returning back to the
preparation file from the solution file doesn’t help us in modifying the surface normal and
various other parameters.

27
Online help: Even though Harvey Bryan and Sayyed Mohammed Autif have explained
about the benefits and drawbacks of this program, at present this program is no more in
production and has no online support.

Desktop Radiance:
Modeling & Input: All the surfaces have the thickness as infinitesimal hence the
surfaces can’t have two different materials on their either sides. The concept of surface
orientation may work only for the transparent surfaces in this lighting software program
due to the negligible thickness.

Daylight set up: Limited locations specified in the program, is well cooperated by
the use of custom buttons which allow us to manually feed the geographical positioning
(latitude, longitude, time-zone and turbidity) options etc. The simulations can perform
illuminance, luminance and daylight factors.

Surface properties: Well defined library is a great boon for the users designing the
space for lighting analysis. Material editor can help users to modify the materials as
desired.

Simulating/ Rendering: This software program uses the backward raytracing
techniques for simulations. The three modes of simulations include the batch mode,
interactive mode and no-image mode where in the interactive mode starts in a window of
draft image of the simulation setup.

28

Output: The output from the simulations can be saved for further processing in
various other software programs.

User interface: The dropdown menu in the menu bar is a real ease to use. The
plug-in capability in AutoCAD does not needs much of explanation about the procedure
to use. The initial stages of operating is very easy and needs no much explanation for the
new users thought the later stages turns little complicated which needs a clear
understanding.

Online help: The help tutorials are very comprehensive and well enhanced.

Lumen Micro:
Modeling & Input: The capability to import the dxf and dwg of AutoCAD file format
is being supported by the Lumen Micro modeler, but the serious limitation include the
incompatibility to simulate complex shapes and forms of geometric models.

Daylight set up: Artificial lighting analysis was the main reason for the
development of this software program and hence its ineffectiveness to perform the
daylighting analysis with out specifying the luminaire was a setback. This setback can be
overcome by assigning the zero wattage for the luminaire and place it in the analysis zone
which will not contribute to any artificial lighting and hence daylighting is not affected
externally from any other artificial lighting components.

29

Surface properties: The non-availability of predefined material library is compensated
by the opportunity to specify the custom material properties by the user. The one most
predominant feature of this program lies in its ability to create a default workplane grid
surface under its own command for the lighting analysis.

Simulating/ Rendering: This program uses the radiosity technique to perform the
light calculations. The calculations can be simple and quick for direct calculation mode
and take good amount of time if commanded to perform the multi surface calculations
(indirect light calculation mode). The whole of the surfaces are broken into smaller
polygons which calculate the light values incident on them using the radiosity technique.

Output: This program has an admirable feature to produce the analysis output in
form of iso-lumen/ rendered images. The output information is Lightscape compatible for
photorealistic rendering.

User interface: The sequential order of the steps provided by the program helps in
a designated path of approach towards the analysis. The program saves a lot of time due
to the well organized simple and easy sequence of steps to be followed.

Online help: The Limited amount of online help availability is not of much concern as
this being a simple interface which has less dependency on out side help other then the
user knowledge and skills.

30

FormZ RadioZity:
Modeling & Input: They consider this program as a most sophisticated modeling
program with advanced features which can support the CAD interface.

Daylight set up: The daylighting parameters are set through the geographical
positioning and lacks in the direct daylight setup options.

Surface properties: This program consists of a well organized library of materials
which can be custom modified on will of the users.

Simulating/ Rendering: This program uses the radiosity technique to run the
analysis of lighting.

Output: It is unfortunate to know that this program can generate only the
photorealistic lighting analyzed images and walk-throughs.

User interface: The basic introduction of the use of this program is required for the
users though some of the working process can be easy to understand due to the
designated icons in the task bar of the main menu.

Online help: The help features are available mainly for the prime definitions of lighting
concepts which can also guide us about the use of the available icons.

31

Comments from the author of this thesis:
There is no testing being performed to support the statement of Harvey Bryan and
Sayyed Mohammed Autif. Most of the statements are general observations which are
qualitative and the authors don’t show any quantitative analysis. This paper gives a broad
understanding about the lighting software programs but doesn’t test or evaluate the
accuracy or range of error in the lighting concepts included in the daylighting software
programs.

RESEARCH PAPER – 4
The fourth paper is written by Robert J.Hitchcock
11
with the aid of building
technologies program, energy and environment division, LBNL and university of
Southern California on a topic: Advanced Lighting And Daylighting Simulation: The
Transition From Analysis To Design Aid Tools. This paper was presented at the
international Building Performance Simulation Association (IBPSA) Fourth International
Conference in Madison, Wisconsin, Aug 14-16, 1995 and was published in the
proceedings. The paper was intended to explore the three significant software
development requirements for making the transition from standalone lighting
simulation/analysis tools to simulation based design aid tools.

11
R.J.Hitchcock, “Advancing Lighting and Daylighting Simulation: The transition from analysis to design
aid tools” May 1995.
Presented at the international building performance simulation association fourth international
conference, Madison, WI, August 14-19, 1995, and published in the proceedings.
Available online: http://www.btech.lbl.gov/papers/37285.pdf. (Downloaded: Aug 10, 2006).

32
His emphasis’s is more on the need for creating the simulation based design aid
mechanism that closely associate lighting and daylighting analysis into the building life-
cycle system.
He has specified some of the very required capabilities in the lighting software
program which are important for lighting analysis, as shown below:
¾ Ability to determine the interior lighting levels.
¾ Potentiality to measure the light comfort levels.
¾ Ability to use the actual weather data for the analysis.
¾ The swiftness of the program while running the analysis.
¾ Ability to quickly adjust the modifications and render the analysis output.
¾ Compatibility of data exporting for integration into design process.

BRIEF EVALUATION OF SOFTWARE PROGRAMS BY ROBERT J.HITCHCOCK IN HIS PAPER:

1. SUPERLITE: The DOS based system using the radiosity technique to analyze the
direct/indirect light in the space. This program can analyze the lighting on
workplane height but unfortunately does not possess any visual comfort
calculation system.
2. DOE-2.0: This is an energy evaluation software program for building sensible and
latent head loads. This program analyzes glare, daylighting factors, artificial
lighting integration and their thermal load impacts. The author (R.J.Hitchcock)
considers the disadvantages of this program as being the limitations of spatial
lighting distribution and a less accurate split-flux algorithm.

33
3. DELIGHT: The author (R.J.Hitchcock) mentions in his present paper that delight is
a lighting and daylighting analysis engine developed from SUPERLITE and DOE-2
algorithms. He concludes saying that Delight lighting software program is still
under the stages of development and integration.

COMMENTS FROM THE AUTHOR OF THIS THESIS:
There is nothing much explained about the testing of the software programs for
daylighting and most of the paper explains about the qualitative properties of the lighting
software programs. There are no instances of evaluation or checking the accuracy of the
programs and no report of proof to support the statement being shown.

The current status of some of the daylighting software programs analyzed from the
above papers of their available at present is as follows
1. Lightscape: This program is acquired by Autodesk and is being incorporated
in Autodesk 3D VIZ-4. The reason behind the action is suggested to be the
low sales of this standalone product.
2. Desktop Radiance: This program had great improvements and developments
with time. The programs associated with Radiance also grew with its success.
This program is now considered as one of the best daylighting software
programs presently available.
3. Lumen Micro: This program is now called as Lumen Designer which has the
strong CAD supportive engine associated within along with the old concepts
of Lumen Micro.

34
4. Form Z Radiosity: This is the successor of the Form Z solid modeling
software which includes the radiosity based rendering of the LightWorks
engine. This product is still active with the research and development.
5. SuperLite2.0: This product was released by LBNL (Lawrence Berkeley
National Laboratory) which is based on radiosity technique running on
DOS/Windows mode of operating systems. This is no active research or
developments being witness these days.

35
CHAPTER – 3.0

METHOD

TYPICAL METHODS FOR DETERMINING LIGHT LEVELS
This chapter will explain the importance of a method (formula) for a lighting
software program and the various formulae being used to calculate the light levels with in
the space. There are some physical parameters that can vary the light levels in the space,
which are briefly explained for the better understanding of their importance. Some of the
professional lighting software programs (for artificial lighting) have already included a
few of these issues discussed in this chapter, but is very important to understand how they
perform.
For every work process there is a need for a method or procedure to be followed
for a systematic approach towards solving a problem/issue. This systematic approach will
help us in remembering the procedure to follow, preserve the data for further use and
overcome the problems or errors (trouble shooting) which make the whole working
process very stable, easy and fast. This is also true for software designing and its end-use.
For a required correct output from the software program, everyone has to follow a
procedure/sequence of steps to perform the analysis using the software as a tool. Since
software is written as a sequential order of functions, every user has to follow the
procedure exactly as written in the program command which will help the computers to
understand and analyze the input.

36

This is also the same for lighting software programs. These lighting software
programs are designed in the form of commands on a computer language which will
perform the tasks as we assign. Hence this whole process is a sequential working order
which needs a method to be followed by both the designer (manufacturer) and end-user.
One can also say that the method to be followed is a formula for the problem/issue (task).
To understand the procedure or method to be followed, we also need to be aware
of the time dependent parameters. Once we know all these parameters, than we can write
a method/working procedure depending upon the formula of what to calculate and on
which parameters is the whole process dependent. For example, in determining the lamp
luminance one has to consider the time parameter of lamp loss factor which is dependent
on various other conditions. Hence while writing the formula for luminance using the
software program; one has to include all these parameters (lamp loss factors, etc.) as the
subset of the formula which the lighting software program will ask us to determine the
value during input. The computer/software then calculates the input values using the
formula and produces the solution (output). This whole process can sometimes be very
complicated and may need many multiple calculations which are performed by the
processor (hardware) of the computer.
Some of the practical lighting design issues that a software programmer may also
need to include in the design of the lighting software programs for both present and
future are mentioned as follows.

37

General suggestions on lighting software design for real practical use.

• Switching of light fixtures in design helps save energy hence lighting softwares
should also incorporate switch/dimmer controls during the design analysis which can
generate various design typologies.
• Lighting software should be able to categorize the various light fixtures types/ lamp
source and help the user to select the appropriate for the prescribed job type (libraries,
museums, etc.).
• The lighting softwares should be able to compare the design job lighting with base
case design using the appropriate codes (Title-24, LEED standards etc) which will
save both energy and revenue making it extra productive.
• Daylighting design can be more productive using the software which can perform
analysis more accurately and at faster pace then humans due to the complexity.
• Softwares should be able to decide the minimum light levels required to be placed in
design depending upon the surface material properties that’s being used.

There are many mathematical methods (formula) being used in the calculation of
illuminance from an electric source. The most commonly used methods are ‘inverse
square method’ also called “grid point method” and the ‘Lumen method’ also called
“room cavity method” or the “zonal cavity method.” Some of the lighting software
programs use this method (formula) for the calculation of light levels with in the space.

38
Inverse square method
In the inverse square method, only the direct light beam arriving from the source
onto the receiving surface is calculated and all other indirect light beams from reflected
surfaces are not considered. This method considers the light arriving from a source as a
point source and is effective only if the distance from the source is at least five times as
large as the diameter or length of the source. The grid layout can also calculate a group of
fixtures termed as point grid method.
This method can help in calculating the amount of light passing through a surface
normal to the beam direction at a given distance from a point source. The use of the
trigonometric cosine factor helps in the calculation of lighting for the non perpendicular
surfaces.
Mathematically: E = I (cos β) / d
2

Where: E = Illumination at desired point on the receiving surface expressed in foot-
candles (fc) as the unit.
I = the luminous intensity at the source when viewed from the direction of the
receiving surface expressed in candela as the unit (cd).
β = it is the angle between a line from the source to the surface and a vector
normal (perpendicular) to the receiving surface.
d = the distance between the source and the surface.

The luminous intensity in a given direction is a polar coordinate plot of the fixture
intensities, which in the past was called as the candlepower distribution curve but is now
also called as photometric test data.

39
Most of the lighting software programs explain about the specific light fixture luminous
distribution in terms of the photometric data which helps in understanding the light
distribution originating from the source radiating into the space all around. This data
helps designer understand the light spread (distribution pattern) from the lamp source
radiating outwards represented on a plane in the 3d space.
Abney’s law is used for the case of multiple fixtures which states that the light
arriving onto a surface is a combination of all light arriving from all the sources (primary
and secondary) to which it is exposed. Thus one can say that the inverse square law when
used for the multiple sources can be added to obtain the formula for the point grid
method.
For the point grid method:
E = { [ I
1
(cos β
1
) / d
1
2
] + [ I
2
(cos β
2
) / d
2
2
] + ……….+ [ I
n
(cos β
n
) / d
n
2
] }.
Hence one can infer that the direct light component from all different fixtures
with in a space can be linearly added to arrive at a whole value of the direct light
component, which doesn’t consider any indirect light or reflected light from any other
surface.

Lumen Method
The Lumen method is based upon the pre-calculated tables of the coefficients
depending upon the fixture type. These coefficients generate from the light distribution
pattern by the fixture considering various factors such as the incident surface reflectance,
orientation if the fixture, workplane height, etc. The coefficient of utilization values range
from 0.0 to 1.0 though typically the values are in-between 0.5 to 0.8 for most of the cases.

40

The light loss factor generally expressed as the decimal or percentage value
should be considered while performing the light calculations. The light transmitting from
the source generally undergoes the transmission loss during its course of travel from the
source to the receiving surface which results in a reduction in useful light. This is an
important parameter which almost all the lighting software programs should include.
There are two types of light loss factors, non-recoverable light loss factor and
recoverable light loss factor.
Non-recoverable light losses are due to ballast factor, ambient temperature of
fixture, voltage variations, optical factor, fixture surface depreciation, etc. which is
inevitable where as recoverable light losses can be reduced by proper maintenance and
cleaning.

Ballast Factor
Lamps and ballasts both undergo loss of wattage during their operation. The
ballast factor is the percentage of the lamps actual lumen output to the rated lumen output
when configured to a specific ballast type.

Ambient temperature of fixture
Fluorescent fixtures are deeply affected to deliver the actual lumens when the
fixture temperature falls out side the ideal fixture temperature.

41

Supply Voltage Variation
Variation of the supply voltage will result in the variation in the lamp lumen
output. The more the voltage supplied than specified can result in more light output but
when the voltage exceed the permissible limit can permanently damage the lamp and the
ballast associated with it. This can also cause fire accidents due to the short circuit in the
wiring. A small variation in voltage when attached with the electronic ballast is not easily
perceivable but is clearly visible in lamp output when attached with magnetic ballasts.

Optical Factor
The size of the lamp surface can affect the light output since lamps have mass
which reduces the light output. This factor is considered as the optical factor. Thinner
lamp, larger is the optical factor.

Fixture Surface Depreciation
The internal surfaces of some fixture types depreciate with time of use which is
more like the wear and tear of the fixtures. Some of these light loss factors like room
surface dirt depreciation, fixture (luminaire) dirt depreciation etc are recoverable because
they are dependent on the maintenance factor.

Lamp Burnouts
The lamps burn out when used more than their rated lamp life. Hence lighting
design software programs should be able to provide the ideal time of lamp burnouts.

42
This will give the contractor sufficient time to replace them before all the lamps fail to
function which are more over a recoverable light loss factor. Practically this lamp life
rating is given by the manufacturer which is the time taken for 50% of the lamps to
burnout completely from a set of testing lamps.

Lamp Lumen Depreciation
The lamp output decreases with time when used during their final stages of lamp
life depending upon the type of lamp. The maintenance staff can take the necessary
action to replace all the lamps periodically under a systematic procedure to avoid any
irregular lamp burnouts. This is sometimes considered as the 40% of lamp life for the
service oriented buildings.
Table-2: Typical LLD values for typical lamps
12
.
Lamp type LLD
F32T8, 85 CRI 0.91
F96T12/CW "Slimline" 0.88
F96T12 "Slimline," 85 CRI 0.94
F96T12HO/CW 0.83
F96T12/HO, 85 CRI 0.90
Compact fluorescent 0.85
Mercury vapor 0.79
Metal halide 0.83
High pressure sodium 0.91

12
Table on Lamp lumen depreciation, (www.lightsearch.com). “Light Guide: Light Loss Factor”
.Available online: http://www.lightsearch.com/resources/lightguides/lightloss.html.
(Downloaded: Aug 10, 2006).

43

Fixture (Luminaire) Dirt Depreciation
The dirt is a major factor in the luminaire dirt deprecation which reduces the
lumen output of the lamps. This is a recoverable factor which can be overcome by
periodic maintenance and cleaning. The extent and intensity of this factor varies with
type of function of buildings, environmental location, extent of exposure, proximity for
maintenance and cleaning, etc. The fixture type maintenance category is available in
IESNA Lighting Handbook which categorizes the group as I to VI. This categorized
group helps in determining the luminaire dirt depreciation factor.

Examples of each categories:
Category I: An industrial strip fixture with no top or bottom enclosure.
Category II: A direct-indirect fixture
Category III: An industrial strip fixture with an apertured top and bottom.
Category IV: Deep-celled parabolic fluorescent fixtures.
Category V: A lensed fluorescent troffer.
Category VI: A pure indirect fixture is a Category VI

The final light loss factor is the product (multiplication) of all the respective light loss
factors (recoverable and non recoverable light loss factor) which are used for the light
level calculations.

44
Lumen Method:
The general form of equation (Lumen Method) is:
E = ( N x n x LL x LLF x CU ) / A.
Where :
E = the illuminance (fc)
N = the number of fixtures
n = the number if lamps per fixture
LL = the number of lumens produced per lamp
LLF = the combined light loss factor
CU = the coefficient of utilization from the tables
A = the area of the working plane (or floor) that will be illuminated by the
fixtures.
The determination of the CU requires the calculation of the room cavity ratio
(RCR). In the zonal cavity method (lumen method), the room space is categorized into
three sections. The upper section or the zone is the space between the lamp fixture and
the ceiling which in case of suspended fluorescent ceiling is the length of the suspension
and for the recessed lamps the value is zero.
The zone between the workplane and the fixture plane is the zone related to the
wall and the amount of light reflected varies with the aspect ratio of the space. Based on
the ceiling cavity ratio, wall and the ceiling reflectance of the corresponding surface
areas, the weighted average reflectance is determined which is also called as the effective
ceiling reflectance (ρ
c
). This is the zone lying between the upper and the lower zone.

45
The zone in between the workplane and the floor must be considered. This may
vary anywhere in depth from the working plane platform height to containing just the
floor itself, if floor illumination for the foot traffic is the main aspect for consideration.
This determines the effective floor reflectance ( ρ
f
).
Hence it can be concluded from the above concept that more light will be
absorbed by tall narrow spaces than the low wide spaces. The formula for determining
these aspect ratios is termed as the cavity ratio and hence been expressed mathematically:
Cavity ratio = 5 x h (length + width) / (length x width).
= 5 x h (L + W) / (L x W).

Fig.C3.1: Illustration of room dimension for cavity method

LUMEN METHOD WORK SHEET OF PROF. MARC SCHILER.

Project Number and Name: __________________________
Design illuminance (E) desired at workplane: ____________

46

Fig.C3.2: Illustration of cavity method for a room.
Luminaire Data:
Manufacturer: ______________________ Type:___________________________
Catalog Number: ____________________ Number of fixtures: _______________
Lamp Data:
Type and color: _____________________ Number per luminaire (n) : _________
Lumens per lamp (LL): _______________
Room cavity ratios
Length = _____________________ Width = ______________________
CCR = 5 x h
cc
x (L + W) / (L x W)
= _______________________
RCR = 5 x h
rc
x (L + W) / (L x W)
= _______________________
FCR = 5 x h
fc
x (L + W) / (L x W) = ________________
Effective ceiling cavity reflectance = ________________
Effective floor cavity reflectance = _________________

47
Coefficient of Utilization (CU) = ___________________
Light Loss Factors
Non Recoverable factors:
Lamp Lumen depreciation (LLD): _________________
Initial Lumens: ________________________________
Or maintained lumens (LL): ______________________
Recoverable factors:
Luminaire Dirt depreciation (LDD): ________________
Room surface dirt depreciation ( RSDD): _____________
LLF = LLD x LDD x RSDD x (other) = _______________
Formulae
For the number of luminaries needed to attain the design illuminance (E) use:
N = E x A / (n x LL x LLF x CU) = ___________________
For illuminance resulting from a given number of luminaries use:
E = (N x n x LL x LLF x CU) / A = ____________________

Visual comfort
The direct glare of the luminaire is determined by comparing the maximum
verses the average luminance of that luminaire for different range of angles which lie in
the field of view. The VCP (visual comfort probability) method evaluates all of the
luminaires within a specific field of view and thus combines the VCP of each to
determine a “discomfort glare rating” (DGR). The method is further explained by Guth
(1966) for the basic principles and DiLaura (1976) for computer applications.

48
Glare is defined as the unwanted light in a visual scene as perceived by the eye.
Bright surfaces when exposed to high intensity of light, may cause a temporary blinding
effect. The glare is often classified as direct or indirect which is also termed as reflected
glare. The contrast is calculated using the equation generated by

Blackwell which is represented as shown below.
C = abs { [(E
o
ρ
o
) – (E
b
ρ
b
)] / (E
b
ρ
b
)}

Where: C = the Contrast
E
o
= illumination on the object.
E
b
= illumination on the background.
ρ
o
= reflectance of the object.
ρ
b
= reflectance of the background.
If the above equation is modified slightly which includes the real contrast in the
real situation from a specific viewpoint is known as the “color rendition factor” (CRF).

CRF = abs [ (L
o
– L
b
) / L
b
]
Where L
o
= Σ [ E
(n)o
x β
(n)o
]
L
b
= Σ [ E
(n)b
x β
(n)b
]

The object sample points are (n)
o
and the background sample points are (n)
b

49
CHAPTER – 4.0

DATA
This chapter will discuss the procedure followed for selecting the daylighting software
programs from various programs available in the market and the special tests performed
on these selected daylighting software programs to judge their accuracy, efficiency and
ease of use on Windows based platforms for both natural and artificial lighting. Though
the concentration of this thesis is on daylighting seeing the importance of the role played
by the artificial lighting in the present days, it has been included for the analysis of the
selected lighting design software programs. It is also an easy way to test simply luminous
relationships as simulated by the programs.
Daylighting simulation tools have been available for many years and the
computer simulations of these daylighting calculations and renderings have been a great
help for lighting designers and architects. These Daylight design software programs are
intended to provide a very high accuracy in their results for natural lighting and artificial
lighting.
The preliminary steps to identify the daylighting software programs started with
collecting the information of the presently available lighting software programs. The
information about the available lighting software programs was gathered from the
internet, books and journals and a chart was prepared to identify the software programs
which best suits our requirements to be considered for comparing and analyzing them. An
online search was performed to identify the available lighting software programs and cut-
sheets were prepared. The cut-sheets are brief enough to explain about the capabilities
and the features available in those lighting software programs. [Refer to appendix C].

50
A small survey was conducted by asking 10 different people related to the
concerned fields of lighting and architecture. This method was adopted to identify what
the user’s wants in a lighting software program and what is the rank order of the features
and their preferences according to the high to low levels of importance. Their information
and feedback was important to identify the various factors and features that have to be
tested for identifying their accuracy. With their input information a rank order list was
prepared depending upon the parameters and features which most considered important
according to their opinion which was also what the author though was an appropriate
judgment. A process of filtering was performed on these various available lighting design
software programs (LDSPs) out of which only four LDSPs were successful enough to
pass the preliminary selection test for my thesis. This thesis was looking for the LDSPs
which are PC compatible and can run for both daylighting and artificial lighting. We have
selected four different software programs which passed the above mentioned challenges
and also those which are used by most of the lighting designers in US. They were AGI32
version 1.84 from Lighting Analyst, 3D studio Max-8 from Discreet, Desktop Radiance
version 2.0 (beta) from LBNL and Lightscape release 3.2. The following Table- 1 show
the sorting out process of the four software programs from a cluster

Legend for the Table – 3 as shown below:
√ Available
O Not sure
X Not available
Web Web based tool

The * represents the software programs which are free to download for the web.

51
Table – 3: Sorting list of lighting software programs for testing.
S.NO TOOL CHARACTERISTICS
Daylighting.
Photometric
(ies)
PC
compatible.
Description.
1. 3D Studio Max 8.0 √ √ √
Good graphics and
animations
2. Adeline √ O X Non standard (US) CAD
3. Agi32 √ √ √
Many lighting designers
are using
4. Bsim2002 X X √ -
5.* Building design advisor √ X √ No complex 3 D geometry
6.* Daylight √ X √
Calculates for Uniform
sky only
7.* Desktop Radiance √ √ √
A research project
( LBNL)
8.* Daysim √ O √ Based on Radiance
9. Ecasys X X Web -
10. Eco Lumen X O √
No out door lighting/
daylighting
11.* EcoAdvisor X O Web
Needs refinement and
clarifications
12. ecotect √ O √
Awareness on data
processing required
13. Energy Profile Tool X X Web -
14.* Envstd and ltgstd X X √ No software updates
15. Flucs √ √ √ No for complex shapes
16.* HiLight X X √
No illumination
calculations
17. Lesodial √ O √ Restrictive data
18. Lighting Boy √ O √
Calculates power
consumption
19. Load Express X O √ For Load calculations
20.* Radiance √ √ X
Lacks Graphical user
Interface
21.* Radiance control Panel √ O √
Needs Desktop Radiance
support
22. Radiance Interface √ O √ -
23.* SkyVision √ X √
No complex building
shapes
24. Sombrero 3.01 √ X √ -
25.* SuperLite √ O √
Non interactive Inputs/
Outputs
26.* The Lightswitch Wizard √ X Web
Limited building
geometry
27.* Visual X √ √ No renderings
28. Lightscape √ √ √ No more in Production

52
Criteria list of importance in lighting software programs
• Illuminance.
• Luminance.
• Specularity.
• Reflectance of materials.
• Transmittance of materials.
• Absorptance of materials.
• Shininess.
• Color coding Graph (False Color).
• Iso-lumen contour graph.
• Point by point illuminance/ luminance values.
• Glossiness.
• Ambient light.
• Outdoor/indoor daylighting calculations.
• Latitude and altitude inputs.
• Unusual and complex shape of Buildings.
• Importing files of all Geometrics shapes.
• Inputs for various atmospheric conditions.
• Values for Uniform/cloudy sky.
• Rainy day analysis.
• Complete weather data.
• Shadow and shade patterns.
• Material library.

53
• Materials characteristics( Transparent, Translucent, etc
• Rendered image quality (Photo realistic).
• Spectrum characteristics.
• Importing .ies files. (photometric data)
• Large file sizes importing.
• Various import/ export of file choices.
• Computer platform (operating system) compatibility.
• Ease of use of software program.
• Levels of analysis ( introductory to advanced)
• Tutorial and help command features.
• Tech support.
• Fenestrations (Light shelves, sky lights, etc)
• Preformatted text file output of data.
• Plotting.
• Video animations/ walk through.
• Visual comfort levels.
• Floor surface area coverage.
• Glare analysis.
• Daylight factor distribution.

54
CHAPTER - 5.0
TESTS AND RESULTS

In order to identify the performance and accuracy of the software programs, there is
always a testing stage. Almost all the software programs in real life are tested before their
launch to check the performance. These tests are performed by the manufacturer and are
sometimes not very precise on the concepts. They may get the software approved because
it is working and able to give an output for the assigned task. These people may not
always be testing the accuracy of the program which gives a scope for the users to reveal
the hidden bugs within the software programs.
Lighting design software programs may also have similar challenges that are to be
addressed by the lighting professionals who are using them in their day to day life. These
challenges are called bugs in the software which have to be corrected before the launch of
new versions of the software programs. The lighting software programmers and the
debuggers might have done a good job in making these lighting software programs to
run, but this thesis is oriented towards organizing some lighting concept tests with some
depth on these working programs and check the accuracy and performance of the lighting
concepts. This can help to expose the possible bugs hidden within these lighting software
programs which can be corrected for better and more accurate performance of the
programs for lighting designers.
There is often a difference between what is being claimed by a software program
and what it actually calculates. The sorted lighting design software programs as shown in
the previous chapter are assigned some challenges to be performed.

55
The specularity is the first test, so every-one of us are eager to know if the
program can calculate a single reflection from a specular surface? To know the answer
for it, a test has been designed and named the specularity test. The Specularity test is
categorized into two different sections where the first one is to run the test on artificial
lighting as the light source. The second test was with natural lighting (Daylighting) as the
light source. For designing the tests, great care is being taken to reduce the number of
variables so that we are least affected by various other factors and also we can track and
identify the right reason and troubleshoot the factor which is causing the variation.
The first test challenge was on specularity with an artificial light source as a light
emitter and the specular wall acting like a mirror and the floor to capture a reflected light
bounced off the specular wall. A room 40 foot in length 20 foot wide and 20 foot high
has been designed and oriented with its longer axis to east west direction. The inside of
the north wall is made specular like a mirror and the rest of the walls were non-specular
matte surfaces (diffuse surfaces). The wall and ceiling also share almost the same
properties as the rest of the walls except the north wall. We want to aim the artificial light
source from the ceiling onto the centre of the north specular wall and check if the light
emitted from the lamp is aimed on to the specular wall and casts a reflected light patch on
the correct location on the floor. By moving the light source we want to make sure that
light is reflected in the right manner and the images on floor are not just the reflections of
the wall image but rather a reflected spot cast onto the correct location. The test
performed is explained both graphically and verbally below in Fig.C5.1

56

Fig.C5.1: Room plan with fixture layout.
Fig.C5.1 shows the basic plan for setting up the test apparatus and technical
information about the orientation and the positioning of the lamps and aiming of light
beams. The room is rectangular with all adjacent sides being perpendicular (makes 90°
with adjacent surfaces). Three lamps, designated Lamp-X, Lamp-Y and Lamp-Z, were
located along the longer axis (center line) such that each lamp is 10 feet away from
adjacent lamp. The lamp-X is 10 feet away from adjacent wall. These lamps were placed
on to the ceiling like ceiling surface fixtures and are oriented such that each lamp aims
exactly to the centre of the interior surface of the north specular wall. Graphically the
spot of the target will be 20 foot from east or west wall and 10 foot above from floor
level which is also 10 foot below ceiling surface on the north specular wall. The Lamp-X
is oriented at 45°, Lamp-Y at 90° and Lamp-Z at 135° from room axis in plan view.

57
It is very important to remember how to use trigonometric calculations while
orienting lamps/fixtures when looking into the section graphically. This is a critical
position where people can go wrong seeing the sketch of room section and
underestimating the tilt of the lamp to be same for all three lamps aiming on to the north
specular wall. The terminology might look confusing if we are not aware of the
architectural lighting definitions of the terms ORIENTATION, TILT, ROLL and SPIN as used
by most of the lighting designers and experts. Special care has been taken so that we are
not confused and hence the definition with graphical diagrams has been illustrated.
Graphical representation has an icon (coordinate axis) in black box showing the direction
of view.

Orientation:

Fig.C5.2: Luminaire Orientation diagram.

58
Looking at the fixture aiming downwards in plan view, when rotated counter-
clockwise is the orientation of the fixture. In plan view, when the fixture is aiming
towards the (-ve Z-axis), 0° starts at (+ ve X-axis) and 90° is at (+ ve Y-axis) which
continues with 180° at (- ve X-axis) and 270° at (-ve Y-axis). The world coordinate
system of the lighting software program should be the same as the local coordinate
system of the model (fixture) generated. In short, the orientation is the angle between the
(+/-) X and (+/-) Y coordinates and the axis of rotation is along (+/-) Z-axis.

Tilt:

Fig.C5.3: Luminaire Tilt diagram.

Looking at the fixture in elevation as shown above, rotating the fixture counter-
clockwise with its centre being the Y axis of the world coordinate system is the tilt of a
fixture. Tilt is 0° at (+ve) X-Axis and turns 90° when rotated towards (+ve) Z-Axis.

59
This continues to 180° at (-ve) X-Axis and 270° at (-ve) Z-Axis. Tilt is the other aiming
angle applied when placing a fixture in AGI.
Example: When looking towards north having a light fixture in front of us aiming
straight down, tilting a fixture 90° keeping the orientation at 0° will make a fixture
(luminaire) point towards North. If the light fixture is tilted 90° with the orientation at
90° will make it (fixture/ photometric nadir) point towards north at horizon.

Fig.C5.4, Luminaire Roll diagram.

Roll:
The fixture rolls on its X-Axis with the centre of a fixture passing through a local
X-axis. When a light fixture takes the roll from 0° to 90°, it turns from (+ve) Y-axis to
(+ve) Z-axis. Roll angle continues to 180° at (-ve) Y-axis and takes a value of 270° at
(-ve) Z-axis. This is the third parameter used while aiming the lamp fixtures in AGI.

60
Example: When looking towards north having a light fixture in front of us aiming
straight down, a Roll angle as 90° considering the orientation of 0° and tilt of 0° makes
the fixture (photometric nadir) aim towards north.

Fig – C5-5, Luminaire Spin diagram.
Spin:
When looking towards north having a light fixture in front of us aiming straight
down, the spin of a luminaire takes place along the Z-axis. The spin is positive when
looked at a luminaire from top towards (-ve) Z-axis makes the luminaire move from
(+ve) X-axis towards the (+)ve Y-axis. The centre of the luminaire is not always through
Z-axis of the world coordinate system icon as seen in Fig-C5-5.
Example: A Spin angle of 135 degrees when considered with having an
Orientation of 0° and Tilt as 90° will Spin a luminaire about the Z-axis by 135°.

61

Fig.C5.6: Cross section of test room with light fixtures placement.

The above diagram represents the section along the shorter axis of the room
where a lamp tilts and the path of light normal emitted from a fixture lamp is been
demonstrated. Looking at the above section, there are chances that we may assume the
roll assigned to the above lamp as 45° and it is same for all lamps. The Lamp-Y requires
the roll of 45° to position its lamps normal light beam onto the centre of north specular
wall but for in case of Lamp-X and Lamp-Z, the roll is 55° (the tilt also changes with roll
angle in the present case). Presuming all lamps make the same roll, will definitely make
the lamp aiming inaccurately and disoriented at the centre of north specular wall. While
dealing with such situations it is very important that we look at the room’s 3D model and
not anymore as 2D plans and sections on a paper. The lamps are assigned the VNSP
(very narrow spot) lamp configuration so that the light beam from fixture is very narrow
and there is not much spill of the emerging beam of light from the source.

62
The lighting design software program can input IES files which are the
photometric file data of some specific fixture deigned by the manufacturer. Each lamp
type will have a different IES file for different lamp categories and fixture types. For the
present case MR16 – VNSP - 7° (GE Lighting – 20816.IES) has been selected which is a
very narrow beam angle of 7°. The MR -16 (Multi-segmented Reflector) lamps have a
very tight optical control and can shoot light for longer distances with less light spill
away from beam centre line.
Lamps were aimed to spot onto the centre of the north specular wall which could
reflect that light onto the floor at a point mathematically calculated on the matte finish
(diffuse) floor. Any light beam which hits a specular surface bounces off the surface at an
angle equal to incident angle. In the present case, the north specular wall is a mirror like
specular surface and the floor is a second matte surface receiving that reflected light.
Tests were performed in three cases where in each case one lamp is on and the other two
were kept off. In case 1, Lamp-X is ON but Lamp-Y and Lamp-Z are kept OFF. This will
help to identify the light aiming appropriateness in each case. The angle of view was
fixed for consistency in testing.
With a very basic configuration, the tests were performed on 4 different lighting
design software programs which were Desktop Radiance, 3D Studio max, Lightscape and
AGI32. A separate check-sheet was prepared which has all the configuration of
parameters applied to a program while testing and all test outputs produced after the
analysis/simulation.

63

TEST FOR SPECULARITY (Artificial Lighting)

Software: Desktop Radiance

Definition: The surface is considered specular if light bounced off the material doesn’t
scatter but retains any reflected image (such as with a mirror) and the angle of reflection
is equal to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto
the centre of the North wall as shown in drawing Fig – C5-1 and Fig – C5-6.

Material Properties
Table – 4. Material properties for specularity (artificial lighting) test.
Testing
Terminology
Desktop
Radiance
Terminology
North wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance (%) 95 49.7 49.7 49.7 96.7 80
Specularity Shininess (%) 95 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Roughness Roughness (%) 2 0 0 0 0 0
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Surface
Orientation
Interior Interior Interior Interior Interior Interior
Self
illumination
-
n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittan
ce
Transparency
(%)
0 0 0 0 0 0
Refractive
Index
Refractive Index
n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name
Luminaire
Reflector
Green-
7K708
LES091
Green-
7K708
LES091
Green-
7K708
LES091
RAL
1013
Oyester
_white
Luminai
re
Support
material

64
Table – 4. (continued).

Material
Texture
Procedural
texture
n/a n/a n/a n/a n/a n/a

Hue n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a
Color
Colo
r
Value n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing n/r n/r n/r n/r n/r n/r
Calculation type
Luminance/
Illuminance
n/r n/r n/r
Luminan
ce/
Illumina
nce
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type R40 flood reflect skir, 45º cutoff – LBNL
Daylighting Daylighting u/s ( no )

Luminance
rating
n/a

u/s Unselect the option as we are not using these parameters in the present case
n/r Not Required as we are not using these parameters in the present case
n/a Not Available as the software doesn’t ask for these values in the present case

Tests:
Table – 5. Lamp configuration table for testing specularity (artificial lighting).
Test-1 Test-2 Test-3

Lamp-X On Off Off
Lamp-Y Off On Off
Lamp-Z Off Off On

65

Test anticipation:
Run tests for artificial lighting. Identify if we find any reflected light patch on diffuse
floor bouncing off the specular north wall emitted by a lamp source aimed towards centre
of north specular wall from ceiling. The complete configuration on aligning the lamps
and the room dimensions, etc is expressed diagrammatically in Fig C5-1 and Fig C5-6.

Results:

Fig C5.1.1.1: Illuminance color plot, human sensitivity image.

The light aimed onto the center of north specular surface doesn’t seem to be
aiming properly. The output image is not very clear to explain what really is happening
with the lamp aiming onto the north specular wall. Though the lamp was aimed into the
centre of the north specular wall, but still we find the light being off-centered. The
irregular and non definite patches on the floor grid make the task of recording the light
level very difficult.

66

Fig C5.1.1.2: Test – 1 result for specularity (artificial lighting).
Note: The lamps Y & Z are not seen as they were deleted to run the test with one lamp
ON (Lamp-X on).

These tests might have to be re-performed with a narrower beam spread lamp.
We are unable to find any sharp specular light patch of light being reflected from the
north specular wall surface onto the floor. Re-testing is performed by varying the lamp
tilt accordingly and the rendered iso-lumen, color coding images are shown below.
Note: We see some hinting traces of reflected light in iso-lumen image and color coded
image in Fig C5.1.1.4. This information is not sufficient to give a clear conclusion about
this lighting design software program passing the specularity test.

67

Fig C5.1.1.3: Iso lumen image and color coded image for luminance.
The software program Desktop Radiance did not pass the specularity test with artificial
lighting as it couldn’t provide the spot of reflected beam on the floor.

Experiences during testing:
During the process of the testing using this software program, there were many
occasions where adjustments were forced to be made and modification had to be
experienced. In the Desktop Radiance it was not very easy to assign a new IES file
(photometric file) to a fixture though it is very easy to select a lamp fixture from the
library. There is no option for the user to change or modify the photometric data of a
fixture from the library directly. It consumes a great amount of time to redesign and
assign photometric data to the fixture drawing and saving or importing a file in/from a
different format named .rif.
After assigning the lamp photometric data and when running the test, modifying
the lamp orientation or changing the directions afterwards doesn’t sometimes update
changes and hence we may sometimes see the lamp aim to an old point rather then
changing its aiming to a new assigned point. This can cause big problems leading to an
error in final lighting calculations while designing on a large scale projects.

68
Most of the instances designers have no/less time to go through all of the drawings in a
very detailed and specific fashion.
This software program has a scroll down menu to assign materials, luminaires,
glazing and furnishings for designed surface or spaces. After spending considerable time
assigning these variables, the user is asked to assign a tedious work of organizing the
analysis process where they set the orientation, camera and/or reference grid or reference
point. After spending so much valuable time assigning that entire configuration, comes
the simulation stage where we perform the test simulation for an output from the testing
model. Many times these programs don’t give the simulation output due to some error
while assigning the above mentioned configurations and the program doesn’t even inform
us about possible types of error(s) nor the method for locating the error. Just to be
successful with our test we may have to select the AutoCAD drawing from base level
stage and then apply all materials and new luminaire etc and reach a stage of simulation
during which we lose a lot of time.
If we are simulating a model with the reference grid as the analysis, the program
gives us an ANSI text file (.txt) compatible enough to easily export into a Microsoft
Office Excel document. The final output is not very easy to understand and doesn’t give
any clear information about which light sensor the light value is coming from and where
is it located as it doesn’t name the sensors. The table below is an example to demonstrate
the above mentioned case. The table is an extract of the information available from the
window work plane grid from the output results of a simulated test. The Fig C5.1.1-5
shows workplane grid and the table- 4 is export information to an excel format.

69
Table - 6. Extracted light level values from workplane grid in Fig C5.1.1.5
0 240 0.0101 2847.35029
12.30769 240 0.0101 2790.7532
24.61539 240 0.0101 1340.88258
36.92308 240 0.0101 1336.05753
49.23077 240 0.0101 1329.55071
61.53846 240 0.0101 1332.68912
73.84615 240 0.0101 1363.06469
86.15385 240 0.0101 1381.81538

These values continue as the number of grid sensors increase in a model.

Fig C5.1.1.4: The workplane grid from desktop radiance simulation.

Once we pass through the simulation stage process and using the camera as an
analysis tool, instead of the grid sensors, this program gives a rendered window which is
a 3-dimensional model of the rendered space. This opens up in a window which has an
option for modifying the parameters of camera and various others as seen in Fig C5.1.1.6.

70

Fig C5.1.1.5: The winview image output from the simulation.

While changing a few of the parameters in the above Fig C5.1-6 as an example,
we some times encounter a situation where the above window crashes and are forced to
rerun the start command in the simulation manager window to get back the new window
for the above output. All the assigned values return to default and we have to reassign the
required values. Due to this problem occurring all time, it is very wise to note the values
all time during analysis/ simulation process so as to save time during the working
process.
One method of viewing an interior space is to cull off the walls whose normals
are away from the viewer to have a clear vision of the inside space.

71
Desktop radiance follows a method where all wall and ceiling surfaces are retained and
only a space falling under the culled zone is made invisible which sometimes makes it
difficult to analyze the space from few specific angles.

BACKFACE VISIBILITY OFF BACKFACE VISIBILITY ON

Fig C5.1.1.6: Back face visibility.

In the above two images, the one on the right has all surfaces visible which have
their surface normal away from the eye of the viewer. The image on to the left has the
surfaces which are culled but all the surfaces are visible hence making it tough to read the
drawing and understand it to analyze the whole image. Thus, the image on to the right is
very easy to read compared to one on the left. To overcome this situation we have to use
the back face visibility option. This tool can turn on or off the walls whose surface
normal is pointing away from your viewpoint. This tool is useful when we wish to see
through rear side of a building. When the camera is placed, both the inside and the
outside of a building can be viewed instantaneously in review. For this tool to work, the
surface normal of all wall surfaces must be oriented inwards into a building. This tool
turns off all those wall surfaces whose surface normal is pointing away from viewpoint.

72
This could be the display option where the undeserved light calculations on surfaces are
made invisible and the analysis just shows the values which we requested.

The rendered images in artificial lighting specularity test are some times not
accurate enough to make any conclusion on test performed. The output data of an image
is very inaccurate as seen in Fig C5.1.1-8. We see that the floor has patterns of patches
(green and red color patches). These patches lead to inaccurate light values when
calculated on the floor which is one of the major setbacks. Though the accuracy of a
model simulation was opted for maximum, the image output is still not satisfactory
enough to be used for analysis of test result.

Fig C5.1.1.7: Color coded image for luminance

73

TEST FOR SPECULARITY (Artificial Lighting)

Software: 3D Studio max-8

Definition: The surface is specular if light bounced off a material doesn’t scatter but
retains any reflected image (such as with a mirror) and the angle of reflection is equal to
the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto the centre of
the North wall as shown in the drawing Fig – C5-1 and Fig – C5-6 .

Material Properties

Table – 7. Material properties for specularity (artificial lighting) test.

Testing
Terminology
3D studio max
Terminology
North wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance map Assign n/a n/a n/a Assign n/a
Specularity Specular level 999 0 0 0 50 0
Diffuse Soften 0 0 0 0 0 0
Roughness Glossiness 100 0 0 0 0 0
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Shader 2 sided
2
sided
2
sided
2
sided
2 sided 2 sided
Self
illumination
-
n/a n/a n/a n/a n/a n/a
Opacity Opacity 100 100 100 100 100 100
Transmittance - n/a n/a n/a n/a n/a n/a
Refractive
Index
Luminance glow
0 0 0 0 0 0
Material
Texture
Texture Map u/s u/s
u/s u/s
u/s u/s
Bounce coefficient 1 1 1 1 1 1

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

74
Table – 7 (continued).

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Light
calculation
Exposure control
Luminance/
Illuminance
n/r n/r n/r
Luminance/
Illuminance
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20186.IES) equivalent.
Daylighting Daylighting u/s ( no )
Luminance rating n/a

u/s Unselect the option as we are not using these parameters in the present case
n/r Not Required as we are not using these parameters in the present case
n/a Not Available as the software doesn’t ask for these values in the present case

Tests

Table – 8. Lamp configuration table for testing of specularity (artificial lighting).
Test-1 Test-2 Test-3

Lamp-X On Off Off
Lamp-Y Off On Off
Lamp-Z Off Off On

Test anticipation:
Run tests for artificial lighting. Identify if we find the reflected light patch on floor
bouncing off the specular north wall emitted by lamp source from ceiling.

Results:
The test was performed and the south west isometric view was chosen for the
consistency. The wall and the floor materials assigned were clearly visible in the image
rendered window of the lighting design software program – 3D studio max-7.0.

75

Fig C5.1.2.1: Specularity test simulation results (test-1) in 3D Studio max – 8.

NOTE: The lamps X, Y & Z are not seen as they were hidden while running the test with
one lamp ON (Lamp-X on).

From the rendering plot for the Test-1 we see a bright specular light spot on floor
reflected off north specular wall from a lamp source (Lamp-X). The light aimed from
Lamp-X is able to cast reflection onto other corner of room successfully. This whole
image of the floor is also visible on the north wall as an image. The north wall being
mirror like was able to retain the image of the floor which will show that graphically the
material assigned was able to perform as a specular surface. Now its time to know if this
material is also able to record the light pattern as assumed for Test-2.

76

Fig C5.1.2.2: Specularity test simulation results (test-2) in 3D Studio max – 8.

From the rendering plot for Test-2, a bright specular light spot on floor is seen
reflected off the north specular wall from the lamp source (Lamp-Y). Light aimed from
Lamp-Y which is the middle lamp is able to cast light reflection below a lamp which is a
good sign of specularity test working.
We are able to find the specular light being reflected from the north specular wall surface
on to the floor.
Therefore the software program (3D studio max -8) did pass the specularity test but has a
fudge factor involved in it.

77

Experiences during testing:
In 3D studio max-8, the specularity test at initial stages was unsuccessful. During
the initial phase of the testing the north wall of the room was made specular by increasing
the specularity and the glossiness to the maximum. The other surfaces were non specular
and hence they just retained the default value anticipating that the surfaces could be
considered as diffuse/matte surfaces. Having these as the main parameters the surfaces
were rendered with having the lamps assigned as mentioned in the test. There was a great
flexibility controlling the lamp and hence the lamp was assigned an equivalent
configuration as that of the MR-16 – VNSP - 7° (GE Lighting – 20186.IES) equivalent.
The lamp falloff and hotspot was continued to 7° which mimics the lamp used in all other
test for specularity with artificial lighting.
After the test simulation, we were expecting the light emitted from the lamp to
aim onto the center of the north specular surface and bounce back on to the floor casting
a light patch on the floor. The light from the lamp fixture was able to aim exactly on to
the target as anticipated but failed to cast any reflected light bounced off the north
specular wall onto the floor. Later on it was figured out that this software program require
the user to assign the caustic and global illumination parameters to the test. This option
helps in assigning the photons to the reflected light and makes them cast a light patch on
the floor. There was great flexibility in controlling the size of the photon and number of
the photons to be used for the rendering.

78
This fudge in the 3D studio max-8 not only makes the work more complicated but
also it creates a room where the final outputs can be manipulated. If they are not
considered or not known to the user before running such a test and can result in
completely wrong outputs. For the best results, we have to apply the raytrace map and
reflection map to the required surface.
The default values are not suitable to run the tests for specularity. They have to be
modified and new parameters have to be assigned to get the required outputs as
anticipated. There is always a great need for the user to be experienced and well aware of
not only the commands in this software program but also the expected results in order to
use it effectively and to achieve the desired outputs.
It can be said this software program (3D Studio Max) by default has nothing
assigned and wants the user to specify each and every concept for the analysis. This in
one way is like creating our own environment and analyzing it which may work well for
the graphics development but is never a right option to analyze the light and its
properties. This software program is more like mimicking the reality to the possible
extent and to our desired choice and like.
People have to be aware of this issue and should take the necessary precautions to
avoid the undesired, unrealistic outputs during the lighting analysis. Only a 3D studio
max expert can clearly tell what values to assign and the method to follow to reach to the
right output. This will certainly cause a lot of inconvenience for the amateur users losing
a lot of productivity time in the case of offices. This software program certainly should
get the credit for its high capability to render the model to look almost real and natural.

79

TEST FOR SPECULARITY (Artificial Lighting)

Software: Lightscape

Definition: The surface is specular if the light bounced off the material doesn’t scatter
and retains any reflected image (such as with a mirror) and the angle of reflection is equal
to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto
the centre of the North wall as shown in the drawing Fig – C5-1 and Fig – C5-6.

Material Properties
Table – 9. Material properties for specularity (artificial lighting) test
Testing
Terminology
Lightscape
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 2/2 1/2 1/2 ½ 1/2 1/2
Specularity Shininess 1 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Roughness - n/a n/a n/a n/a n/a n/a
Color Bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface
Orientation
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Self
illumination
Luminance glow 0
0 0 0 0 0
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transparency 0 0 0 0 0 0
Refractive
Index
Refractive Index 1 1 1 1 1 1
Material
Texture
Texture > Name None None None None None None

Procedural
texture
u/s
u/s u/s u/s u/s u/s

80
Table – 9 (continued).
Hue 0.0 29.96 29.96 29.96 29.96 29.96
Saturation 0.0 0.6 0.6 0.6 0.6 0.6 Color Color
Value 1.0 0.5 0.5 0.5 0.5 0.5

Light sensors
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Calculation type
Luminance/
Illuminance
n/r n/r n/r
Luminance/
Illuminance
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting u/s – no
Luminance rating Percentage – 100%

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Tests:
Test-1 Test-2 Test-3

Lamp-X On Off Off
Lamp-Y Off On Off
Lamp-Z Off Off On
Table – 10. Lamp configuration table for testing of specularity (artificial lighting).

Test anticipation:
Run tests for artificial lighting.
Identify if whether we can find the reflected light patch on the floor bounced off the
specular north wall emitted by the lamp source from the ceiling. This is considered as a
good lighting software program by many users and hence the expectations are very high
about its capabilities.

81

Results:
We are unable to find any specular light being reflected from the north specular wall
surface onto the floor. The expected light patch on the floor at the anticipated point, as
indicated above is not generated. Light is scattered evenly (diffusely) from the north
specular wall. The images shown below in fig C5.1.3.1 and fig C5.1.3.2 demonstrate that
the light aimed onto the centre of the north specular wall is not reflected and the specular
light spot onto the floor even thought the material properties of the surfaces of north
specular wall was assigned. Table 9 shows the values assigned to make surface specular.

Fig C5.1.3.1: Specularity test simulation isometric view (test-1) in Lightscape.

82
.

Fig C5.1.3.2: Specularity test simulation raytrace image (test-1) in Lightscape.

Luminance - logarithmic Luminance - linear

Fig C5.1.3.3: Specularity test simulation raytrace image (test-1) in Lightscape and color
coded luminance plot for logarithmic and linear scales.

83
We are unable to find any specular light being reflected from the north specular
wall surface on to the floor even from the ray traced image.
Therefore the software program (Lightscape) didn’t pass the specularity test for
the artificial lighting.

Experiences during testing:
In this lighting software program (Lightscape), the specularity test was a failure.
There were no traces of reflections found on the floor bouncing off the north specular
wall. We had high expectations for this software program. Many designers believe in
Lightscape for performing specularity and hence the tests were performed several times
upon failure.
This software program is no more in production due to which the availability of
this package is less which made a tough time to get it. This software program is available
in multi disks which contain the library of material and other accessories, which are now
hard to find as people often sell the main program compact Disk and all other extra
compact disks may not be available. There are very little posting s online about this
software program due to which people learning first time from scratch finds it a very
tough time with out the user manuals. The user manuals are very helpful, as they clearly
explain the working process and the procedure working on this software program. \
People/ users buying this software program from others are suggested to even buy
the manual books which are going to be a great help at time of need, which is worth like a
help tutorial from the manufacturer.

84

TEST FOR SPECULARITY (Artificial Lighting)

Software: AGI32

Definition: The surface is specular if the light bounced off the material doesn’t scatter
and retains any reflected image (such as with a mirror) and the angle of reflection is equal
to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto
the centre of the North wall as shown in the drawing Fig – C5-1 and Fig – C5-6.

Material Properties:

Table – 11. Material properties for specularity (artificial lighting) test
Testing
Terminology
AGI
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 1 0.5 0.5 0.5 1 0.8
Specularity Specularity 1 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness
Color bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface Type
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Self
illumination
- n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transmittance n/a n/a n/a n/a n/a n/a
Refractive
Index
Refractive Index
n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None

85
Table – 11 (continued..)
Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Points on surface
Normal
Side
(Front/Top)
n/r n/r n/r
Normal Side
(Front/Top)
n/r
Light meter type
Normal
to
Surface
n/r n/r n/r
Normal to
Surface
n/r
Light-sensor
grid
Grid spacing 1x1 n/r n/r n/r 1x1 n/r
Calculation type Exitance n/r n/r n/r Illuminance n/r
Calculation points On Off Off Off On Off

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -
Luminance rating n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Tests:
Table – 12. Lamp configuration table for testing of specularity (artificial lighting).
Test-1 Test-2 Test-3

Lamp-X On Off Off
Lamp-Y Off On Off
Lamp-Z Off Off On

Test anticipation:
Run tests for artificial lighting. Identify whether we can find the reflected light patch on
the floor reflected off the specular north wall emitted by the lamp source from the ceiling.

86

Results:
The tests are performed with lamp - X on and the other two lamps off. The lamp
is aimed on to the centre of the north specular wall. The simulation is performed after
assigning the values as prescribed in Table – 9. The simulated model provides the data
output in the left window which shows the illuminance values in the present case for the
surfaces to which the calculation grids are assigned. This lighting software program has
the option to calculate the light values and also render the model to give photorealistic
images as shown below in Fig C5.1.4-1and Fig C5.1.4-2. This lighting software program
can also perform the direct and indirect light calculation analysis individually.

Fig C5.1.4.1: Analysis report of test – 1 in AGI.

87

Fig C5.1.42: Raytrace image of test – 1 in AGI.

It can be concluded from the test that. we can’t find any light being reflected from the
specular wall surface on to the floor’s anticipated point. The light from the Lamp -X is
successful to aim on to the centre of the north wall but is not able to reflect the light on to
the anticipated point on the floor. The raytrace image above does not show any traces of a
reflected light spot on the floor caused by the specular reflection from the north wall.
Therefore the software program (AGI) didn’t pass the specularity test for the
artificial lighting.

Experiences during testing:
In this lighting software program (AGI32) the manufacturer says:
“Advanced Surface Properties : This section provides additional surface parameters for
ray tracing applications as well as advanced surface modifications.

88
Specularity (Ray Trace Only) - Indicates the specularity (glossiness or shine) of the
selected surfaces. By default, the value is 0 (no specularity), it may be increased up to 1
(100%, mirror reflection). The value may be entered directly, or specified in the
Specularity dialog. To use the Specularity dialog, click in the Specularity text box, then
click on the ellipsis icon (or Press F4).
Surfaces may be made to look shiny or glossy by adding a Specularity value to their
surface properties. This attribute is only visible in Ray Trace images and is not used in
the numeric and radiosity calculations in any way. It is simply a post process "layer" that
is added to the surface when Ray Trace images are created.

Technical Details
“Specularity Value indicates the amount of incident light that will be reflected
back to the observer in the Ray Traced image.
For example, a Specularity value of 1, indicates that 100% of the incident light on the
surface is reflected back in the reflection image (mirror like). A Specularity value of 0.5,
indicates that 50% of the incident light on the surface is reflected back in the reflection
image”
13
.

13
This information can be accessed from AGI32 HTML Help in AGI.

89

Fig C5.1.4.3: Window from AGI explaining about specularity.

The software program was unable to perform the specularity test for artificial lighting
successfully.

The window states that the specularity in this lighting design software program
(AGI) is used only with raytracing and has no affect on the calculated values. The
specularity sets the intensity of the surface reflective highlights. A mirror would have the
specularity = 1.0, a perfectively diffuse surface would have specularity = 0.0.

90

SPECULARITY TEST (NATURAL LIGHTING)

This chapter explains the process followed for testing the daylighting/ natural
lighting feature in the four Lighting design software program that were selected from a
group of various Lighting design software program. These four Lighting design software
program are Lightscape, AGI32, 3D studio Max-8 and Desktop Radiance which passed
through the screening process for identifying the various effective Lighting design
software program. The tests are little similar to that of the artificial lighting, only that we
are now testing the specularity in daylighting.
The room dimensions measure the same but will have three openings of size 2’ x
2’ exactly located in the position where the artificial lamps were placed in the case of
artificial lighting. These openings have no partition (like glazing, etc) between them
which create a direct link between the interior and the exterior. Some of the Lighting
design software programs may ask the user to define the opening in which it may ask us
sometimes to assign the material and the transparency. If this parameter is brought in to
the testing it can make the whole process complicated and tough to analyze. We are
actually trying to test the Lighting design software program with the least number of
parameters possible in the testing so that the results can be analyzed easily. In the present
case, the room has no glazing for the openings. In the case of artificial lighting the lamps
were used to aim the light onto the north specular surface whereas in the natural lighting
we are looking for the sun to shoot light on the north specular wall surface for which we
have to identify the right solar position and location of the sun.

91
For the sun to aim onto the north specular wall, one has to identify the sun altitude
and azimuth which plays a major role in designing with natural light. In the present case
some of the solar gnomon charts were analyzed and found that for the location of Los
Angeles, the sun casts the shadows exactly along the north- south cardinal axis at 12.00
noon. This implies that the shadows parallel to the line of the north-south cardinal
direction. Fixing this parameter which is the azimuth of the sun, we have to identify the
month which can let us have an altitude of the sun to be as 45°.
In the month of December on the 15
th
at 12:00PM for the location of Los Angeles,
the sun casts the shadow exactly as anticipated for the test. The rays from the sun pass
through the opening in the ceiling and casts light onto the centre of the north specular
wall. This preserves the identicality between the two testing case types of artificial
lighting and natural lighting. All the material properties of the room surfaces remain the
same as was for the case of the artificial lighting test. The surface orientation of the
surfaces in the room is towards the inside, which makes the analysis accurate in
performing the daylighting test for the interiors. The camera is located in the same
position as was for the testing case of artificial lighting which gives the same viewing
angle of the south east isometric in order to facilitate the reader to understand and
compare the outputs for both the artificial and natural lighting tests.
In the case of the artificial lighting, there were 3 lamps labeled Lamp-X, Lamp-Y
and Lamp-Z, having the tilt of 55°, 45°and 55° respectively. In order to achieve the same
conditions in the daylighting testing, the tilting of the sun is difficult as it has both the
altitude and azimuth applied. To overcome this situation to achieve both simultaneously,
it is more appropriate to rotate the building instead of changing the sun position.

92
The sun position was kept constant by not varying the time and date, instead for
the Tests-1 in natural lighting the room was assigned its longer axis making an angle of
45° with the east- west cardinal direction. Thus the sunlight from the slot-X casts a strong
beam of light close to the centre of the north specular wall. We are very much interested
to see the reflected light bouncing off the north specular wall to cast the light patch on the
floor at a mathematically calculated anticipated location on floor. For test-2, where the
direct sunlight was intended to aim exactly onto the centre of the north specular wall
passing through the Slot-Y in the ceiling, the building is oriented with its longer axis
aligning the north-south cardinal direction and a small change in altitude to fix the light
spot onto the centre of north specular wall.
Some of the Lighting design software programs performed well and some other
programs failed even in the case of natural lighting. The testing procedure performed is
explained in detail below.
The Table – 13 helps as the legend in understanding the material properties table for the
various lighting software programs testing which are performed in the tests and results
chapter. These are used at places where the value to be indicated has no option to turn on
or turn off or places where the value can’t be entered in the lighting software program.

Table – 13: Abbreviations used in material properties table for lighting software
programs testing

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

93

Fig.C5.2.1: 3D model of room configuration for natural lighting testing.

The fig C5.2.1 shows the room configuration having the length of 40 feet and width of 20
feet. The height of the room is 20 feet with the ceiling having three opening to the outside
environment. The opening s are placed 10 feet c/c apart from each other and from the
walls. The north interior wall is made specular to run the tests as planned and configured.
The surface materials remain the same for both the artificial and natural lighting tests.

94

TEST FOR SPECULARITY (Natural Lighting)

Software: Desktop Radiance

Definition: The surface is specular if the light bounced off the material doesn’t scatter
and retains any reflected image (such as with a mirror) and the angle of reflection is equal
to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Create the opening slot on the ceiling
at position X and Y, aiming the sunlight onto the approximate centre of the North wall as
shown in the Fig – C5.2-1. Replace lamps with ceiling slots as explained in the ceiling to
allow sun light to pass through it and cast light on north specular wall.
Material Properties

Table – 14. Material properties for specularity (Natural lighting) test
Testing
Terminology
Desktop
Radiance
Terminology
North wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance (%) 95 49.7 49.7 49.7 96.7 80
Specularity Shininess (%) 95 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness Roughness (%) 2 0 0 0 0 0
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Surface
Orientation
Interior Interior Interior Interior Interior Interior
Self
illumination
- n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance
Transparency
(%)
0 0 0 0 0 0
Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a

95
Table – 14. (continued..)
Material
Texture
Material Name
Luminaire
Reflector
material
Green-
7K708
LES091
Green-
7K708
LES091
Green-
7K708
LES091
RAL
1013
Oyester
_white
Luminaire
Support
material

Procedural
texture
n/a
n/a n/a n/a n/a n/a

Hue n/a n/a n/a n/a n/a n/a
Saturat
ion
n/a n/a n/a n/a n/a n/a
Color Color
Value n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r

Calculation
type
Luminance/
Illuminance
n/r n/r n/r
Lumina
nce/
Illumina
nce
n/r

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type -
Daylighting Daylighting Dec15 at 12:00PM for Los Angeles.

Luminance
rating
n/a

For u/s, n/r, n/a terms refer to Table - 13

Tests:
Table – 15. Sun configuration table for testing specularity (natural lighting).
Test-1 Test-2 Test-3
SLOT - X Open Close Close
SLOT – Y Close Open Close
SLOT – Z Close Close Open
BUILDING ANGLE 45 0 - 45

96

Fig C5.2.1.1: Building Orientation process.

Building angle is the smaller angle made between the longer axis of the building
and the east-west cardinal directions. This helps in orienting the sun onto the centre of the
specular wall as illustrated in Fig C5.2.1.1.

Test anticipation:
Run tests for natural lighting.
Identify if we can find the reflected light patch on the floor reflected off the specular
north wall by the sunlight through the Slot – X (opening) from the ceiling for Test 1 &
Slot-Y for Test-2.

97

Results:

Fig C5.2.1.2: Specularity test – 1 in natural lighting (Desktop Radiance).

The light is incident on the north specular wall from Slot-X which is casting a
light patch on the floor at the anticipated point. This to some extent gives a sigh of relief
that at least to an extent this program is able to perform the natural lighting specularity
test. We are not yet sure with this test of what are the light values on the floor and what is
actually incident on the north specular wall. This analysis will help us to uncover the
range of accuracy of the lighting software program (Desktop Radiance).

98

Fig C5.2.1.3: Specularity test – 2 in natural lighting (Desktop Radiance).

We are able to see the light spot on the floor reflected off the north specular wall.

Fig. C5.2.1.4: Specularity test showing reflected specular light bounce on floor
(Desktop Radiance).

99
We see the reflected light from the north specular wall onto the floor in human sensitive
image and color coded image above for Test 1. By the change in the sun position during
the day, the specular light on the floor is moving in the opposite direction which is the
clear demonstration of a successful specularity test.

Fig C5.2.1.5: Isocontour plot confirming specular light bounce on floor
(Desktop Radiance).

Therefore the software program test for specularity (natural lighting/ daylighting)
on Desktop Radiance passed successfully.

Experiences during testing:
In the present software program for lighting (Desktop Radiance), there is a
scroll down menu containing materials, luminaire, glazing and furnishings that can be
selected by following the options in their sub menu to assign them to the model. After
assigning the required materials and their properties to the room, one has to pass through
a tedious task of organizing the model for simulation through the analysis process where
we set the orientation, camera and/or reference grid or reference point. Assigning the
orientation and reference grid or the reference point in this program is very easy.

100
To assigning the camera one has to pass through the series of anticipation and
calculations to assign the direction for the camera and its position.

Fig C5.2.1.6: Window illustrating the camera properties in Desktop Radiance.

The camera height feature in the analysis window which is accessed from
Radiance > Analysis > Define camera position scroll down menu is also somewhat
confusing. The following window opens as shown in Fig C5.2.1-6. The N indicates the
north orientation and the camera properties window has the camera elevation and the
Height relative to the current elevation. Selecting this option requires a good knowledge
and experience on this program for orienting the camera in the winrview window. The
new users can find it very difficult to assign the right configuration to the camera to
capture the required view as anticipated.

101
This option when selected can make us a little confused as it will be a bit tough to orient
the camera to the required point when we are working on the yaw, roll and pitch on the
window. The users do need to spend some extra time to figure out the right position and
orientation of the camera to look to a desired point on/in the model. The Fig C5.2.1-7
shows the winrview window.

Fig C5.2.1.7: Window displaying the winrview property in Desktop Radiance.

During the simulation stages many times the program doesn’t give the simulation
outputs due to some error after assigning all the required material properties and features.
The program doesn’t even inform us about the possible type of error and the location of
that error.

102
Just to be successful with our test we may have to select the AutoCAD drawing
from the base level and then apply all the materials etc and reach the stage of simulation
during which we lose a lot of time for reassigning all the materials and required stuff on
the model thereby retarding the work time efficiency.
As mentioned above in the case of the artificial lighting, the issues about the
challenges using this software program remain the same even for the natural lighting. The
test of specularity in daylighting was successful with this software program. The camera
simulation setup has the accuracy set to medium as default which apparently can’t be
changed to any other option.

Fig C5.2.1.8: Camera simulation window in Desktop Radiance.

The camera simulation window has an option for selecting the entities from the
current drawing. The selected surfaces are analyzed and rendered for the simulation
output. Users can be confused with this option thinking that by selected the surfaces in
the drawing for analysis, it can help us cull the non-required surfaces and the final output
of the simulation would be excluding the unselected surfaces.

103

Fig C5.2.1.9: Image rendered in Desktop Radiance.

The Fig C5.2.1.9 shows the final output of the simulation window in which the
part of the ceiling and the south wall were not selected and the rest of the entities in the
drawing were included in the selection. In the simulation output window (winrview)
shown above, we see that the sun casts the light on the floor and the specular north wall.
In Fig C5.2.1.9 we can see that this software program is considering the surfaces not
selected as non existent. Though in the drawing we have these walls and the ceiling is
present, still the non selected surfaces are not included in the simulation. Hence it can be
concluded that by performing this operation in the present software program that it
considers the non selected entities in the drawing as non existing surfaces. Users should
not consider that by going through this process they will be able to cull the non required
surfaces and could get the required (correct) output.
This lighting design software program (Desktop Radiance) has successfully
passed the specularity test for natural lighting.

104

TEST FOR SPECULARITY (Natural Lighting)

Software: 3D Studio max-8

Definition: The surface is specular if the light bounced off the material doesn’t scatter
and retains any reflected image (such as with a mirror) and the angle of reflection is equal
to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Create the opening slot on the
ceiling at position X and Y, aiming the sunlight onto the approximate centre of the North
wall as shown in Fig.C5.2.1. Replace lamps with ceiling slots as explained in the ceiling
to allow sun light to pass through it and cast light on north specular wall.

Material Properties

Table - 16: Material properties for specularity (Natural lighting) test in 3D studio Max-8
Testing
Terminology
3D studio max
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance/raytrace select n/r n/r n/r n/r n/r
Specularity Specular level 999 0 0 0 50 0
Diffuse Soften 0 0 0 0 0 0
Glossiness Glossiness 100 0 0 0 0 0
Roughness - n/a n/a n/a n/a n/a n/a
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Shader 2 sided 2 sided 2 sided 2 sided 2 sided 2 sided
Self
illumination
Luminance glow
0 0 0 0 0 0
Opacity Opacity 100 100 100 100 100 100
Transmittance - n/a n/a n/a n/a n/a n/a
Refractive
Index
- n/a n/a n/a n/a n/a n/a

105
Table – 16 (continued..)
Material
Texture
Texture Map u/s u/s
u/s u/s
u/s u/s
Bounce coefficient 1 1 1 1 1 1

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Light
calculation
Exposure control
Luminance/
Illuminance
n/r n/r n/r
Luminance/
Illuminance
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type -
Daylighting Daylighting Dec15 at 12:00PM for Los Angeles.
Luminance rating n/a

For u/s, n/r, n/a terms refer to Table - 13

Tests:
Table – 17: Sun configuration table for testing specularity (natural lighting) in 3D Studio
max-8.

Test-1 Test-2 Test-3
SLOT - X Open Close Close
SLOT – Y Close Open Close
SLOT – Z Close Close Open
BUILDING ANGLE 45 0 - 45

The building angle as illustrated in Fig C5.2.1.1 is the smaller angle made
between the longer axis of the building and the east-west cardinal directions. This helps
in orienting the sun onto the centre of the specular wall.

106

Test anticipation:
Run tests for natural lighting. Identify whether we can find the reflected light
patch on the floor reflected off the specular north wall by the sunlight through the Slot –
X (opening) from the ceiling for Test 1 and Slot-Y for Test-2. Table – 15 explains the
process and the parameters to be fixed to run the test. The tests are to be performed in a
controlled manner so that the process of trouble shooting becomes very easy. This
systematic problem approach will help us in understanding it very clearly.

Results:
From the rendering plot for the Test-1 we see the bright specular light spot on the
floor reflected off the north specular wall from the Slot-X. The light aimed through the
Slot-X is able to cast the reflection on the other corner of the room successfully as seen
above. The flooring was assigned a material which best suits the properties of the
material illustrated in table – 14 of the specularity test for the natural lighting in 3D
Studio Max – 8 lighting software program.

107

Fig C5.2.2-1: Image render in 3D Studio max – 8 shows specularity test – 1
(Natural lighting).

Fig C5.2.2-2: Image render in 3D Studio max – 8 shows specularity test – 2
(natural lighting).

108
From the rendering plot for the Test-2, the bright specular light spot on the floor is
seen reflected off the north specular wall from the Slot-Y. The light aimed through the
Slot-Y (middle slot) is able to cast the light reflection below the slot which is a sign of a
successful specularity test. We are able to find the specular light being reflected from the
north specular wall surface on to the floor. The size and shape of the light patch on the
floor confirms that the test performed is successful in this lighting software program
though there is a small fudge factor involved in its analysis and simulations.

Therefore the software program (3D studio max-8) did pass the specularity test for
(Natural lighting/ daylighting) in the specularity tests performed.

Experiences during testing:
In the present software program for lighting (3D Studio Max-8), the specularity
test for the artificial lighting during the initial stages was unsuccessful. After the test
simulation, we were expecting the light to aim on to the center of the north specular
surface and bounce back on to the floor casting a light patch on the floor. The light as
expected was able to aim exactly on to the target as anticipated but failed to cast any
reflected light bounced off the north specular wall on to the floor. Later on it was figured
out that this software program requires the user to assign the caustic and global
illumination parameter to the test. By adjusting some of the parameters (caustic and
photons for global illumination) the specularity test for artificial lighting turned
successful hence same method was followed by using the same settings as the past and
the test was performed on daylighting in this program and it was also successful.

109
The fudge in the 3D studio max was with the photons and the opportunity to vary the size
of each photon and number of photons. Manipulation of final output is easy which leads
an amateur user to incorrect, inconsistent and unanticipated outputs.
For the best results, we have to apply the raytrace map and reflection map to the
required surface. The values to the default are not suitable to run the tests for specularity.
They have to be modified and new parameters have to be assigned to get the required
outputs as anticipated. There is always a great need for the user to be experienced and
well aware of the commands in this software program and the expected output in order to
use it effectively to receive the desired outputs.

It can be said this software program (3D Studio Max) by default has
nothing assigned and wants the user to specify each and every concept for the analysis.
This in one way is like creating our own environment and analyzing it which may work
well for the graphics development but is never a right option to analyze the light and its
properties. This software program is more like mimicking the reality to the possible
extent and to our desired choice and like.
People have to be aware of this issue and should take the necessary precautions to
avoid the undesired, unrealistic outputs during the lighting analysis. Only a 3D studio
max expert can clearly tell what values to assign and the method to follow to reach to the
right output. This will certainly cause a lot of inconvenience for the amateur users losing
a lot of productivity time in the case of offices. This software program certainly should
get the credit for its high capability to render the model to look almost real and natural.

110

TEST FOR SPECULARITY (Natural Lighting)

Software: Lightscape

Definition: The surface is specular if the light bounced off the material doesn’t scatter
and retains any reflected image (such as with a mirror) and the angle of reflection is equal
to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Create the opening slot on the
ceiling at position X and Y, aiming the sunlight onto the approximate centre of the North
wall as shown in Fig – C5.2-1. Replace lamps with ceiling slots as explained in the
ceiling to allow sun light to pass through it and cast light on north specular wall.

Material Properties
Table - 18: Material properties for specularity (Natural lighting) test in Lightscape.

Testing
Terminology
Lightscape
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 2/2 1/2 1/2 1/2 1/2 1/2
Specularity Shininess 1 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness - n/a n/a n/a n/a n/a n/a
Color Bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface
Orientation
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Self
Illumination
Luminance
glow
0
0 0 0 0 0
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transparency 0 0 0 0 0 0
Refractive
Index
Refractive
Index
1 1 1 1 1 1

111
Table - 18: (continued..)

Material
Texture
Texture > Name None None None None None None

Procedural
texture
u/s
u/s u/s u/s u/s u/s

Hue 0.0 29.96 29.96 29.96 29.96 29.96
Saturation 0.0 0.6 0.6 0.6 0.6 0.6 Color Color
Value 1.0 0.5 0.5 0.5 0.5 0.5

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Calculation type
Luminance/
Illuminance
n/r n/r n/r
Luminanc
e/
Illuminanc
e
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type -
Daylighting Daylighting Dec 15
th
at 12:00PM for Los Angeles
Luminance rating Percentage – 100%

Tests
Table – 19: Sun configuration table for testing specularity (natural lighting) in
Lightscape.

Test-1 Test-2 Test-3
SLOT - X Open Close Close
SLOT – Y Close Open Close
SLOT – Z Close Close Open
BUILDING ANGLE 45 0 - 45

The building angle as illustrated in Fig C5.2.2-1 is the smaller angle made
between the longer axis of the building and the east-west cardinal directions. This
arrangement helps in orienting the sun onto the centre of the specular wall.

112

Test anticipation
Run tests for natural lighting. Identify if we can find the specular light patch on
the floor reflected off the specular north wall by the sunlight through the Slot – X
(opening) from the ceiling for Test 1 & Slot-Y for Test-2. The test parameters for the
operations of slots are shown in table – 17. This lighting software program is no more in
production and hence no technical support is available, which makes it necessary for me
to explain the method and systematic procedure of using this program to run the tests.

Sequential steps of working in Lightscape.
The tasks to be performed for running this software program for attaining the required
outputs include the following steps:
• Importing the Data.
• Preparing Data
• Creating the radiosity solution
• Fine tuning the solution
• Outputting the results.

Results:
From the rendering plot for the Test-1 in Fig C5.2.3-1, we see the bright specular
light spot on the north specular wall from the Slot-X but there is no reflected specular
light patch found on the floor surface.

113
The light aimed through the slot-X, slot – Y and slot – Z is able to cast the sharp light
spots in the shape of rhombus and square depending on the sun position successfully but
yet this lighting software program shows no traces of specular light reflected onto the
floor from the north specular wall.

Fig C5.2.3.1: Image render in Lightscape shows specularity test – 1 (natural lighting).

114

Fig C5.2.3.2: Image render in Lightscape shows specularity test – 2 (natural lighting).

Fig C5.2.3.3: Color coded illuminance plot in Lightscape shows specularity test – 2.

115

We are unable to find any specular light being reflected from the north specular
wall surface on to the floor.
….

Fig C5.2.3.4: Color coded illuminance plot in Lightscape showing blue plot in linear
scale and yellow plot in logarithmic scale for specularity test (natural lighting).

The Fig C5.2.3.4 is showing the liner
*
and logarithmic
*
pseudo color coding
images which doesn’t show any red color patch on the floor surface (indicating no
specular reflections on ground) for Test-1.
We are unable to find any reflected light from north specular wall surface onto the floor.
Therefore the software program (Lightscape) couldn’t pass the specularity test for
(natural lighting / daylighting).

Experiences during testing:
In this lighting software program (Lightscape), the specularity test was a failure.
There were no traces of reflections found on the floor bouncing off the north specular
wall even for the natural lighting. We expected this software program to be successful.

116
Many designers trust Lightscape for performing specularity analysis and hence the tests
were performed several times upon failure to increase the confidence level of the test.
The model can be imported from an external program or can be created in the
Lightscape itself. In the present case we have imported the drawing from external
program (AutoCAD) and the materials were assigned to the surfaces. The whole process
of working on this software program is typically into two sections. The initial stage of the
preparation of the working file for developing the model and assigning the materials is
called as the Lightscape preparation file and is saved with an extension .lp in the
Lightscape. The second part of the working process which basically includes the running
of the simulation is saved as solution file having an extension .ls in Lightscape.

Assigning the daylighting configuration for the above test.
Using natural lighting.
Lightscape uses two daylight algorithms: Interior Daylight and Exterior Daylight.

Each method provides an efficient algorithm for the appropriate situation. When
we are using the interior daylight algorithm, daylight and sunlight are only calculated
through surfaces that are specified as a window or an opening.

• A window is defined such that the properties of the materials assigned to a
window (i.e. the material should be transparent) affect the amount and color of
the light that enters the space.
• An opening is treated as if there is no surface there at all.

117
We can modify the following sun and daylight parameters by choosing Light >
Daylight:
• Direction of north
• A city location
• Latitude and longitude
• Time zone
• Day of the year
• Time of the day
• Daylight saving time on/off
• Sun color
• Sky color
• Sky conditions

Fig C5.2.3.5: Daylight set up parameters windows in Lightscape.

118

Setting the global process parameters
Choose the Process > Parameters.
1. This value continues the speed and quality of the radiosity process.
2. Click the wizard button to activate the wizard.
3. Selecting the appropriate radio button will decide the quality of the model
with 5 standing the highest.
4. Click Next to move further.
5. Selecting Yes will activate the daylighting parameter.
6. Click Next to move further.
7. Click Finish to save the information and move out of the wizard
8. Selecting the low mesh spacing (0.25) in the Receiver group box will
allow for close meshing.
9. Initialization Minimum area at 12 in the tolerance group will help in
geometrical refining during the simulation/analysis.
10. Click OK to close Process Parameters dialog in the current window.

119

Fig C5.2.3.6: Process parameter set up window for quality output in Lightscape.

The illuminance rating is the fraction of the area of a surface that satisfies (or
exceeds) a specified criterion. You can use this option to obtain more information about
the distribution of light over a selected surface. About this property, it is further explained
below in illuminance / luminance rating criteria and color /grey scale coding plots.

120

Fig C5.2.3.7: Process parameter set up window for daylight output in Lightscape.

Fig C5.2.3.8: Process parameter set up window for finish wizard in Lightscape.

121

Rules of thumb
It is very important to know the optimum meshing parameters for the specific test
about to be performed using the radiosity solution. The best efficient way is to perform
the testing with a very coarse mesh setting and later refine the settings to a further small
spacing if satisfied about the output that we are looking for. Having a refine mesh spacing
for the surfaces intended for analysis and all other unwanted surfaces if assigned a coarse
mesh setting will help a lot in saving time for the complete analysis.
Users performing the analysis need to run few sample tests to arrive at a required
high level of output, little practice and some patience. The guidelines below will help one
in setting up the initial test parameters.

Receiver group guidelines
To determine the Mesh spacing maximum and minimum: Model size ratio 1-10-
100- estimate or determine the average of the length, width and height of the model. For
the present example of a room 40 foot long x 20 foot wide x 20 foot high would have an
average of (40 + 20 + 20 ) / 3 = 26.66 foot
• The mesh spacing maximum should be 1/10 of this value (2.66 foot in the above
example)
• The mesh spacing maximum should be 1/100 of this value (0.26 foot in the above
example).
• The subdivision contrast threshold should be set to 0.8.

122

Source group guidelines:
To determine source group parameters.
• Direct source min – set to the receiver mesh spacing minimum value. (0.26).
• Direct and indirect source subdivision accuracy- set to 0.4.
• Indirect Min- Use the same values that we set for the Receiver Mesh Spacing
Minimum. (0.26).
• Shadow grid Size – Set to Two.
Source: Lightscape, “Lightscape Visualization System, version 3 for Windows NT and Windows 95)”.
Ligthscape Tutorial, 4, 4-30.

Fig C5.2.3.9: Lighting Analysis window setup parameters in Lightscape.

Following all of the above process systematically as mentioned, the final color
coding plot has been obtained which doesn’t show any light reflected off the north
specular wall onto the anticipated point on the floor as shown below. Hence it can be
concluded from the test output below that Lightscape is unable to pass the assigned
specularity test conducted by us for daylighting.

123

Fig C5.2.3.10: Illuminance plot for Test – 2 (natural lighting) in Lightscape.

We expected this software program to be successful. Many designers trust
Lightscape failed in performing specularity analysis and hence the tests were performed
several times to increase the confidence level of the test.

New Test for specularity analysis.
From the above test, except the floor and the north specular wall all other surfaces
are deleted. The analysis is performed for 15
th
DEC at 10:00 AM and 1:00PM. The
simulation output results of rendered image, raytrace image and color coding plot is
shown below. The final test outputs for the above test are shown in Table – 18 which
contains rendered images for testing carried out at 10:00 a.m and 01:00 p.m.

124

Fig C5.2.3-11 shows the rendered image of the exterior space with the Daylight
and Sunlight option ON at 10: 00 a.m.
Fig C5.2.3-12 shows the rendered image of the exterior space with the Daylight
and Sunlight option ON at 01: 00 p.m.
Fig C5.2.3-13 shows the raytrace image of the exterior space with the Daylight
and Sunlight option ON at 10: 00 a.m.
Fig C5.2.3-14 shows the raytrace image of the exterior space with the Daylight
and Sunlight option ON at 01: 00 p.m.
Fig C5.2.3-15 shows the color coded illuminance plot of the test of exterior space
with the Daylight and Sunlight option ON at 10: 00 a.m
Fig C5.2.3-16 shows the color coded illuminance plot of the test of exterior space
with the Daylight and Sunlight option ON at 01: 00 p.m.

All the possible analysis results were searched to see if any of the above
capabilities can record the specular light reflected on to the floor from the highly specular
wall as mentioned about the testing procedure previously.
The results doesn’t show the specular light reflection from the wall reflected on to
the floor. The color coded plot at 1:00 pm shows the reflected light bounce onto the floor
and not specular light bounce.

125
Table – 20: Simulated output results at 10:00 a.m & 01:00 p.m for new test on specularity
(natural lighting) in Lightscape.

At 10:00 AM At 1:00 PM
Fig C5.2.3-11 (Render plot)

Fig C5.2.3-12 (Render plot)

Fig C5.2.3-13 (Raytrace plot)

Fig C5.2.3-14 (Raytrace plot)

Fig C5.2.3-15 (Color coded illuminance
plot)

Fig C5.2.3-16 (Color coded illuminance plot)

Thus the software program Lightscape didn’t pass the specularity test for Natural
lighting.

126

TEST FOR SPECULARITY (Natural Lighting)

Software: AGI

Definition: The surface is specular if the light bounced off the material doesn’t scatter
and retains any reflected image (such as with a mirror) and the angle of reflection is equal
to the angle of incidence. This concept is called specularity

Model: Create a room of size 40’x20’x20’. Create the opening slot on the
ceiling at position X and Y, aiming the sunlight onto the approximate centre of the North
wall as shown in the Fig – C5.2-1. Replace lamps with ceiling slots as explained in the
ceiling to allow sun light to pass through it and cast light on north specular wall.

Material Properties

Table - 21: Material properties for specularity (Natural lighting) test in AGI
Testing
Terminology
AGI
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 1 0.5 0.5 0.5 1 0.8
Specularity Specularity 1 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness
Color bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface Type
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Self
illumination
- n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transmittance n/a n/a n/a n/a n/a n/a
Refractive
Index
Refractive Index
n/a n/a n/a n/a n/a n/a

127
Table - 21: (continued..)
Material
Texture
Material Name n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Points on surface
Normal
Side
(Front/Top)
n/r n/r n/r
Normal
Side
(Front/Top)
n/r
Light meter type
Normal to
Surface
n/r n/r n/r
Normal to
Surface
n/r
Light-sensor
grid
Grid spacing 1x1 n/r n/r n/r 1x1 n/r
Calculation type Exitance n/r n/r n/r Illuminance n/r
Calculation points On Off Off Off On Off

View Camera Position South east isometric view.
Lamp
specification
Lamp type -
Daylighting Daylighting Dec15 at 12:00PM for Los Angeles.
Luminance rating n/a

For u/s, n/r, n/a terms refer to Table - 13

Tests:
Table – 22: Sun configuration table for testing specularity (natural lighting) in AGI.

Test-1 Test-2 Test-3
SLOT - X Open Close Close
SLOT – Y Close Open Close
SLOT – Z Close Close Open
BUILDING ANGLE 45 0 - 45

The building angle as illustrated in Fig C5.2.1-1 is the smaller angle made
between the longer axis of the building and the east-west cardinal directions. This
arrangement helps in orienting the sun onto the centre of the specular wall.

128

Test Anticipation
Run tests for natural lighting. Identify whether we can find the reflected light
patch on the floor reflected off the specular north wall by the sunlight through the Slot –
X (opening) from the ceiling for Test 1 and Slot-Y for Test-2. AGI is the lighting
software program which came into the market recently and is developed commercially
for the lighting designers based in Colorado, USA.

Results:

Fig C5.2.4.1: Simulated test – 1 result in AGI for specularity concept in natural lighting.

It can be concluded from the test-1 that we can find some light reflected from the
specular wall surface on to the floor but it is not at the anticipated point.

129
Fig- C5.2.4.1 shows that the light is not reflected off the north specular wall onto the
anticipated point on the floor. The iso-lux line contour plot represents the high light
intensity points on the floor and on the north specular wall. The high intensity point on
the floor doesn’t match with the anticipated point of high specular reflection. This implies
that this software program is unable to perform the specular bounces off the materials
properly in AGI32.

Fig C5.2.4.2: Rendered image of test – 1 in AGI for specularity concept natural lighting.

The sunlight is successfully penetrated through the Slot-X and was able to cast
light on the north specular wall surface as intended for the test, but failed to cast the
reflected light bounce onto the floor at the right position as anticipated.

130
Though we are able to see some light reflected off the wall on to the floor more diffusely,
which is certainly the concept of reflectivity and doesn’t count under specular reflections.
As mentioned earlier, the light patch on the floor has to be in the form of a rhombus for
test – 1, test- 3 and square in shape for test-2 reflected off the north specular wall from
the ceiling slots during the time of the day with various configurations being assigned.
This action of reflections is the clear demonstration of specularity and specular
reflections of the materials in the lighting design software program.

Fig C5.2.4.3: Rendered image of test – 2 in AGI for specularity concept natural lighting.

131

Experiences during testing :

In this lighting software program (AGI) the manufacturer says:
Advanced Surface Properties :-

“This section provides additional surface parameters for ray tracing applications as well
as advanced surface modifications.
Specularity (Ray Trace Only) - Indicates the specularity (glossiness or shine) of the
selected surfaces. By default, the value is 0 (no specularity), it may be increased up to 1
(100%, mirror reflection). The value may be entered directly, or specified in the
Specularity dialog. To use the Specularity dialog, click in the Specularity text box, and
then click on the ellipsis icon (or Press F4).
Surfaces may be made to look shiny or glossy by adding a Specularity value to their
surface properties. This attribute is only visible in Ray Trace images and is not used in
the numeric and radiosity calculations are any way. It is simply a post process "layer" that
is added to the surface when Ray Trace images are created.”
14

14
This information can be accessed from AGI32 HTML Help in AGI.

132

Fig C5.2.4.4: Window from AGI explaining about specularity.

The software program was unable to perform the specularity test for artificial
lighting successful. Therefore the software program (AGI) didn’t pass the specularity test
for (Natural lighting/ daylighting) as assigned.

Test conclusion
The final appearance of the architectural space depends upon the lighting levels
specified, the intensity of the light and the reflectance from the surfaces of the buildings
materials or the surrounding surfaces. The Illuminance and Luminance values vary with
the type of surfaces present within a room. Varying the surface properties like
reflectance, shininess, roughness, transparency, color, etc of walls, floor and ceiling
affect the Illuminance/Luminance with in the space. The following table suggests the
illuminance values for use in primary design.

133
Table – 23: Typical materials surface properties and estimated illuminance output from
the surfaces
15
.

approximate
reflectance
typical
materials*
surface
condition
illuminance (lux)/ district
brightness†
low medium high
clean 15 25 40
fairly clean 20 35 60 0.8 white brick
fairly dirty 45 75 120
clean 20 35 60
fairly clean 35 55 90 0.6 Portland stone
fairly dirty 65 110 180
clean 30 50 80
fairly clean 45 75 120 0.4
middle stone,
medium
concrete fairly dirty 90 150 240
clean 40 60 100
fairly clean 55 90 150 0.3 dark stone
fairly dirty 110 180 300
clean 55 90 150
fairly clean 80 140 230 0.2
granite, red
brick
fairly dirty 160 280 450

The Fig C5.2.4.5 shows the calculation mode options in Lighting Analyst (AGI)
as an example. The first radio button option is the full calculation mode where the
reflectance and occluding properties of all room and object surfaces are considered in the
calculations. The second radio button option is the direct calculation mode where
reflectance and transmittance values properties of all surfaces are NOT considered in the
calculations. While simulating the model under the full calculation mode, the light level
value output from the program under the influence of the surrounding specular surfaces
will be inaccurate as some of the software programs failed the specularity test.

15
CIBSE Lighting Guide LG6 (1992).
* Based on reflectance for a white light. Values may differ if low pressure sodium or high
pressure mercury lamps, or lamps emitting light of a predominant color are used;
illuminance should then be decided by site trials.
† Typical districts are: low brightness- rural; medium brightness- suburban; high brightness-
town and city centers.

134
Hence the above testing software programs which failed the specularity test
cannot provide full complete accurate illuminance and luminance values within the space
where the surfaces are specular or reflective.
This lighting software program is being used presently by many lighting
designers. The specularity test is certainly a disappointment for the people who are using
this software program unaware of this hidden bug. To regain the trust of existing users,
the manufacturer has to rectify this bug and give a version which can help lighting
designers with accurate results.

Fig C5.2.4.5: Calculation mode switch window in AGI

135
REFLECTANCE TEST

This chapter explains about the process followed for testing the reflectance
property of the materials in the four Lighting design software program that were selected
for testing. These four Lighting design software program are Lightscape, AGI, 3D Studio
Max-8 and Desktop Radiance which passed through the screening process for identifying
the various available effective Lighting design software program. This test looks little
similar to the previous test of specularity performed.
The room dimension measures the same but will be having three lamps positioned
as in the case of the specularity test for artificial lighting. We are actually trying to test
the Lighting design software program with the least number of parameters possible in the
testing so that the results can be analyzed easily. In the present case, the room has no
glazing or the openings.
There are several older units of luminance:
Apostilb (deprecated) 1 asb = 1/pi cd/m2
Blondel (deprecated) 1 blondel = 1/pi cd/m2
Candela per square foot 1 cd/ft2 = 10.764 cd/m2
Candela per square inch 1 cd/in2 = 1550 cd/m2
Footlambert (deprecated) 1 fL = 3.426 cd/m2
Lambert (deprecated) 1 L = 104/pi cd/m2
Nit 1 nit = 1 cd/m2
Skot (deprecated) 1 skot = 10-3/pi cd/m2
Stilb (deprecated) 1 sb = 10'000 cd/m2

136

Typical luminance values:
16

1.6 x 10
9
cd/m
2
Solar disk at noon.
600,000 cd/m
2
Solar disk at horizon
120,000 cd/m
2
Frosted bulb 60 Watt
11,000 cd/m
2
T8 cool white fluorescent
8,000 cd/m
2
Average clear sky
2,500 cd/m
2
Moon surface
2,000 cd/m
2
Average cloudy sky
0.0004 cd/m
2
Darkest sky

Flow chart of the photometry and lighting.
17

Fig.C5.3.1: Flow Chart of Photometry and Lighting.

Contributing author for photometry and lighting: Thom Beaulieu.

16
http://www.schorsch.com/kbase/glossary/luminance.html
17
http://hyperphysics.phy-astr.gsu.edu/Hbase/vision/photomcon.html#c1

137

TEST FOR REFLECTANCE
Software: Desktop Radiance

Definition: The surface is reflective if the light bounced off the material scatters in all
directions and doesn’t retain any reflected image (such as with a white surface and the
angle of reflection is equal to the angle of incidence). This concept is called reflectivity.

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto the
centre of the North wall as shown in Fig – C5.2-1.

Material Properties

Table - 24: Material properties for 100% reflectance test in Desktop Radiance

For 100% Reflective Surface
Testing
Terminology
Desktop
Radiance
Terminology
North
wall
South
wall
West
wall
East wall Floor Ceiling

Reflectance
Reflectance
(%)
100 1
1 1 100 1
Specularity Shininess (%) 0 0.5 0.5 0.5 0 0.5
Diffuse - n/a n/a n/a n/a n/a n/a
Roughness
Roughness
(%)
0 15 15 15 0 15
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Surface
Orientation
Interior Interior Interior Interior Interior Interior
Self
illumination
-
n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittanc
e
Transparency
(%)
0 0 0 0 0 0
Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a

138
Table - 24: (continued..)

Material
Texture
Material
Name
RAL9003
_Signal
_White
Luminai
re
Baffle
material
Luminai
re
Baffle
material
Luminaire
Baffle
material
RAL900
3_Signal
_White
Lumina
ire
Baffle
materia
l

Procedural
texture
n/a
n/a n/a n/a n/a n/a

Hue
n/a n/a n/
a
n/
a
n/a n/a
Saturati
on
n/a n/a n/
a
n/
a
n/a n/a
Color
C
o
l
o
r
Value
n/a n/a n/
a
n/
a
n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r

Calculation
type
Luminance/
Illuminance
n/r n/r n/r
Luminan
ce/
Illuminan
ce
n/r

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type High bay narrow clear HID (175W, 12000Lumen, 1lamp fixture)
Daylighting Daylighting u/s ( no )

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table - 25: Material properties for 50% reflectance test in Desktop Radiance

For 50% Reflective surface

Testing
Terminology
Desktop
Radiance
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance (%) 50.41 1 1 1 100 1
Specularity Shininess (%) 0 0.5 0.5 0.5 0 0.5
Diffuse - n/a n/a n/a n/a n/a n/a
Roughness Roughness (%) 0 15 15 15 0 15

139
Table - 25: (continued..)

Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Surface
Orientation
Interior Interior Interior Interior Interior Interior
Self illumination - n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance
Transparency
(%)
0 0 0 0 0 0
Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name
RAL50
24_Past
el
_violet
Lumina
ire
Baffle
materia
l
Lumina
ire
Baffle
materia
l
Lumina
ire
Baffle
materia
l
RAL90
03_Sign
al
_White
Luminai
re Baffle
material

Procedural
texture
n/a
n/a n/a n/a n/a n/a

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a
Color
C
o
l
o
r
Value
n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r

Calculation
type
Lumina
nce/
Illumina
nce
n/r n/r n/r
Luminan
ce/
Illumina
nce
n/r

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type High bay narrow clear HID (175W, 12000Lumen, 1lamp
fixture)
Daylighting Daylighting u/s ( no )

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Tests:

Table – 26. Material configuration table for reflectance testing in Desktop Radiance

Test-1 Test-2

North Wall Reflectance 100% 50%

140

Test anticipation:
Run tests with the specified artificial lamp.
Calculate the amount of light arriving the surface at the centre of the wall where the lamp
is aimed and compare it with the amount of light bouncing off the surface at that specific
point. For the 100% reflective surface the illuminance should be equal to exitance and for
the 50% reflective surface the exitance should be half the illuminance.

Results:

Fig C5.3.1.1: Simulation rendered image of test – 1 in Desktop Radiance for reflectance

141
Test-1 shows the reflectance test for the 100% reflective surface (north wall) where the
lamp-X was aimed on to the centre of the north reflective wall. The test-2 was for the
north reflective wall having the reflectance of 50%. The illuminance and the luminance
values of the north reflective wall were printed and organized as shown below in table -
27. The amount of light received on the surface at the point on the north reflective wall
having the light aimed onto it should be equal to the amount of light bouncing off the
wall (north reflective wall), if the north reflective wall is 100% reflective. Hence in
simple words the illuminance equals exitance at a point on the north wall having the light
aimed from Lamp-X. For the north wall having the 50% reflectance should have its
exitance equal to half the illuminance at the above specified point.
The final plots of the tests show that for the Test-1 having the north wall 100%
reflective bounces off the same amount of light received at the point specified for the test.
The illuminance color coded image looks similar to the luminance color coded image and
hence the amount of light arriving the surface equals the amount leaving the surface. The
units used for calculating the illuminance is ‘Lux’ and for the luminance it is ‘nits’. The
‘nits’ as the term for unit of luminance is rarely used. The clear explanation about this
unit is explained below.

142
Table - 27: Test results of 100% reflectance properties for materials in Desktop Radiance.

TEST ON 100% REFLECTIVE NORTH SURFACE WALL
ILLUMINANCE LUMINANCE
Fig C5.3.1.2 (render image)
Fig C5.3.1.3 (render image)
Fig C5.3.1.4 (iso-lumen plot)
Fig C5.3.1.5 (iso-lumen plot)
Fig C5.3.1.6 (color coded plot)
Fig C5.3.1.7 (color coded plot)

143

The above images in table – 26 show the Test-1 (reflection test) for the north
reflective wall surface with 100% reflective surface properties. The first set of images
show the illuminance and luminance plot of the room (isometric view) and the second set
show the iso-lumen contour plots and the third set of the images show the color coded
graph of the room. The left column has the illuminance plots and the right column has the
luminance plot for the specific test.
The light aimed onto the center of the north specular surface doesn’t seem to be
aiming properly. The light is cast just above the centre of the north specular wall. While
aiming the lamp, special precautions were taken and a check has been performed before
the analysis to confirm that the lamp was aimed properly, but still the final outputs show
that the lamp is not aiming onto the intended position. Thus while performing the test
(analysis) using the artificial lamps, special precautions and care have to be taken to
overcome the inaccurate output results. During this process sometimes we may have to
rerun the simulation several times and check visual if the lamp aiming is onto the desired
position as required.
From the above test we can infer that the 100% reflective surface is able to reflect
almost the same amount of light from the surface as it was receiving. Thus illuminance
almost equals luminance in the present case at a point centre of the light spot on the north
reflective wall.
Similar method is being followed to perform the test – 2 which is with the north
wall being assigned the 50% reflectance properties instead of 100% as in the previous
case. Testing procedure remains unchanged and the final output is as shown below in
table – 28.

144
Table - 28: Test results of 50% reflectance properties for materials in Desktop Radiance.
TEST ON 50% REFLECTIVE NORTH SURFACE WALL
ILLUMINANCE LUMINANCE
Fig C5.3.1.8 (render image)
Fig C5.3.1.9 (render image)

Fig C5.3.1.10 (iso-lumen plot)

Fig C5.3.1.11 (iso-lumen plot)
Fig C5.3.1.12 (color coded plot) Fig C5.3.1.13 (color coded plot)

145
The above image in table – 28 shows the reflective test for the north reflective wall with
50% reflectance. The testing configuration is almost the same except that the north wall
reflectance properties are modified by assigning a new material which has the reflectance
of 50.41% named as (RAL5024_Pastel _violet). In the present case we are comparing the
ratio of luminance at the centre of the light spot on the north reflective wall compared to
illuminance at that point on the surface.

Using the formula L = E x ( ρ)
Where L = the luminance
E = the illuminance
ρ = the reflectance (in the case of reflected luminance).

Hence from the above formula, the luminance is directly proportional to the
illuminance and the reflectance of the surface on which the light is incident. This tells us
that the change in Luminance should vary the illuminance linearly when the reflectance is
constant (not varied). The increase in the reflectance should increase the Luminance
when the illuminance remaining as constant.
The amount of light leaving the 50% reflective surface should be half the value of
illuminance arriving the surface at that point. This is not a careful definition but is rather
a simple way to calculate the value. The 50% reflective surface should have the
luminance half the value of luminance as in for the 100% reflective surface.

146

TEST FOR REFLECTANCE
Software: Lightscape

Definition: The surface is reflective if the light bounced off the material scatters in all
directions and doesn’t retain any reflected image (such as with a white surface and the
angle of reflection is equal to the angle of incidence). This concept is called reflectivity.

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto
the centre of the North wall as shown in Fig – C5.2-1.

Material Properties

Table - 29: Material properties for 100% reflectance properties of materials in Lightscape

For 100% Reflective Surface
Testing
Terminology
Lightscape
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 2/2 0/2 0/2 0/2 0/2 0/2
Specularity Shininess 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness - n/a n/a n/a n/a n/a n/a
Color Bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface
Orientation
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Self
Illumination
Luminance
glow
0
0 0 0 0 0
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transparency 0 0 0 0 0 0
Refractive
Index
Refractive
Index
1 1 1 1 1 1
Material
Texture
Texture >
Name
None None None None None None

Procedural
texture
u/s
u/s u/s u/s u/s u/s

147
Table – 29 (continued..)

Hue 0.0 29.96 29.96 29.96 29.96 29.96
Saturation 0.0 0.6 0.6 0.6 0.6 0.6 Color Color
Value 1.0 0.5 0.5 0.5 0.5 0.5

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Calculation type
Luminance/
Illuminance
n/r n/r n/r
Luminance/
Illuminance
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting u/s – no
Luminance rating Percentage – 100%

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table - 30: Material properties for 50% reflectance properties of materials in Lightscape

For 50% Reflective Surface
Testing
Terminology
Lightscape
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 1/2 0/2 0/2 0/2 0/2 0/2
Specularity Shininess 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness - n/a n/a n/a n/a n/a n/a
Color Bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface
Orientation
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Towards
(inside)
Self
Illumination
Luminance
glow
0
0 0 0 0 0
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transparency 0 0 0 0 0 0
Refractive
Index
Refractive
Index
1 1 1 1 1 1
Material
Texture
Texture >
Name
None None None None None None

Procedural
texture
u/s
u/s u/s u/s u/s u/s

148

Table – 30 (continued...)

Hue 0.0 29.96 29.96 29.96 29.96 29.96
Saturation 0.0 0.6 0.6 0.6 0.6 0.6 Color Color
Value 1.0 0.5 0.5 0.5 0.5 0.5

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Calculation type
Luminance/
Illuminance
n/r n/r n/r
Luminance/
Illuminance
n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting u/s – no
Luminance rating Percentage – 100%

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Tests:

Table – 31. Material configuration table for reflectance testing in Lightscape

Test-1 Test-2

North Wall Reflectance 100% 50%

Test anticipation:
Calculate the amount of light arriving the surface at the centre of the wall where
the lamp is aimed and compare it with the amount of light bouncing off the surface at that
specific point. Check if the materials are properly assigned and the material properties
suit as mentioned in table – 29 and table -30 for their respective tests. The test names are
assigned as shown in table -31in the present test for reflectance using the lighting design
software program Lightscape. This lighting software program is no more in production.

149
Table – 32. Comparison of test – 1 & 2 simulated in Lightscape for reflectance test.

100 % REFLECTIVE NORTH WALL 50 % REFLECTIVE NORTH WALL

FIG C5.3.2.1: PHOTOREALISTIC IMAGE

FIG C5.3.2.2: PHOTOREALISTIC IMAGE

FIG C5.3.2.3: ILLUMINANCE IN TEST -1

FIG C5.3.2.4: ILLUMINANCE IN TEST-2

FIG C5.3.2.5: LUMINANCE IN TEST-1

FIG C5.3.2.6: LUMINANCE IN TEST-2

150

Fig C5.3.2-7: Material properties assigning window in Lightscape

The general material properties assigned for the north reflective wall surface
performing the Test-2 (50% reflective test) is shown above in fig- 78. The transparency,
shininess and the reflective index is assigned the minimum possible and the reflectance
scale is assigned as 1.0 (ranges from 0.0 – 2.0). Assuming that the highest being the
100% reflective equal to 2.0 in reflectance scale and the lowest being the 0% reflective
equal to 0.0 in reflectance scale, and the intermediate being the 50% equal to 1.0 in the
reflectance scale as seen in the above material properties window of Lightscape. In all the
tests, the color bleed scale is always kept constant (highest possible) and is equal to 1.00
in the present software program.

151
The lighting analysis output after the simulation with 50 % reflective north wall surface.

Fig C5.3.2-8: Lighting analysis output window for test - 1 in Lightscape

A point on the centre of the north reflective wall was picked to identify the
illuminance at that point. For the present test, the centre of the north reflective wall when
picked shows the value as (5.92766, 6.0198, 3.22372) as seen above succeeding the
illuminance/luminance value at that point. In the present case the illuminance at the point
is 25260 lux. The above window also shows the average, maximum and minimum light
values.
According to the formula : L = E x ( ρ)
Where L = the luminance
E = the illuminance
ρ = the reflectance (in the case of reflected luminance).

152
Hence from the above formula, the amount of light leaving the 50% reflective
surface should be half the value of illuminance arriving the surface at that point. This is
not a careful definition but is rather a simple way to calculate the value.
The Fig C5.3.2-9 below shows the luminance test output for the 50% north
reflective wall.

Fig C5.3.2-9: Lighting analysis output window for test - 2 in Lightscape

The luminance at the same point (5.92766, 6.0198, 3.22372) has a value 8032.68
cd/m
2
. The point for both the illuminance and the luminance is picked the same to
compare them. The illuminance has the units as ‘lux’ and the luminance has the units as
cd/m
2
in the present test.

153

TEST FOR REFLECTANCE
Software: AGI

Definition: The surface is reflective if the light bounced off the material scatters in all
directions and doesn’t retain any reflected image (such as with a white surface and the
angle of reflection is equal to the angle of incidence). This concept is called reflectivity.

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto
the centre of the North wall as shown in Fig – C5.2-1.

Material Properties

Table - 33: Material properties for 100% reflectance properties of materials in AGI

For 100% Reflective Surface
Testing
Terminology
AGI
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 1 0 0 0 0 0
Specularity Specularity 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness
Color bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface Type
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Self
illumination
- n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transmittance n/a n/a n/a n/a n/a n/a
Refractive
Index
Refractive Index
n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None

154
Table – 33.(continued..)

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Points on surface
Normal
Side
(Front/Top)
n/r n/r n/r
Normal Side
(Front/Top)
n/r
Light meter type
Normal
to
Surface
n/r n/r n/r
Normal to
Surface
n/r
Light-sensor
grid
Grid spacing 1x1 n/r n/r n/r 1x1 n/r
Calculation type Exitance n/r n/r n/r Illuminance n/r
Calculation points On Off Off Off On Off

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -
Luminance rating n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table - 34: Material properties for 50% reflectance properties of materials in AGI

For 50% reflective surface

Testing
Terminology
AGI
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance 0.5 0 0 0 0 0
Specularity Specularity 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a
Roughness
Color bleed Color Bleed 1 1 1 1 1 1
Surface
Orientation
Surface Type
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Single-
Sided
Self
illumination
- n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a
Transmittance Transmittance n/a n/a n/a n/a n/a n/a

155
Table - 34:(continued..)

Refractive
Index
Refractive Index
n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Points on surface
Normal
(Front/Top)
n/r n/r n/r
Normal Side
(Front/Top)
n/r
Light meter type
Normal
Surface
n/r n/r n/r
Normal to
Surface
n/r
Light-sensor
grid
Grid spacing 1x1 n/r n/r n/r 1x1 n/r
Calculation type Exitance n/r n/r n/r Illuminance n/r
Calculation points On Off Off Off On Off

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -
Luminance rating n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Tests:

Table – 35. Material configuration table for reflectance testing in AGI

Test-1 Test-2

North Wall Reflectance 100% 50%

156
Test anticipation:
Run tests with the specified artificial lamp. Calculate the amount of light arriving
the surface at the centre of the wall where the lamp is aimed and compare it with the
amount of light bouncing off the surface at that specific point. Check if the materials are
properly assigned and the material properties suit as mentioned in table – 33 and table -34
for their respective tests. The test names are assigned as shown in table -35in the present
test for reflectance using the lighting design software program AGI. This lighting
software program is for commercial use for the lighting designers.
For the 100% reflective surface the illuminance should be equal to exitance and
for the 50% reflective surface the exitance should be half the illuminance.
The simulation outputs for the test – 1 and test – 2 are shown in fig – 81 and fig –
82 respectively for the reflectance test in lighting software program AGI.

Fig C5.3.3.1: Illuminance output in AGI for test-1 for 100% wall reflectance test.

157

Fig C5.3.3.2: Illuminance output in AGI for test-2 for 50% wall reflectance test.

The value of illuminance is the same as the exitance in the 100% reflectance test
(test-1) and the exitance is half the illuminance in the 50% reflectance test (test-2). The
row of images on the left shows the 100% reflectance case and the row of images to the
right shows the 50% reflectance case (test-2).
It can be inferred from the above images that the software program (AGI) is able to
calculate the values accurately and hence it is able to pass the reflectance test.

158

Fig C5.3.3.3: Exitance output for test-1 in AGI for100% wall reflectance test.

The wall reflectance of the north wall is 100 % for test-1 and the exitance value
recorded by the gird at the centre of the north reflective wall is 36 lumens per square foot.
The area just away from the centre of the north reflective wall has recorded the exitance
values as 30 lumens per square foot. This light is projected from the lamp –X and the rest
if the two lamps (lamp-Y and lamp-Z) were turned off.

159

Fig C5.3.3.4: Exitance output for test-2 in AGI for 50% wall reflectance test.

The wall reflectance of the north wall is 100 % for test-1 and the exitance
value recorded by the gird at the centre of the north reflective wall is 36 lumens per
square foot. The area just away from the centre of the north reflective wall has recorded
the exitance values as 30 lumens per square foot. This light is projected from the lamp –X
and the rest if the two lamps (lamp-Y and lamp-Z) were turned off.

160

TEST FOR REFLECTANCE
Software: 3D Studio max -8

Definition: The surface is reflective if the light bounced off the material scatters in all
directions and doesn’t retain any reflected image (such as with a white surface and the
angle of reflection is equal to the angle of incidence). This concept is called reflectivity.

Model: Create a room of size 40’x20’x20’. Aim the lamps X, Y and Z onto
the centre of the North wall as shown in Fig – C5.2-1.

Material Properties

Table - 36: Material properties for 100% material reflectance properties in 3D studio max

For 100% Reflective Surface
Testing
Terminology
3D studio max
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance map
100
(assign)
n/r n/r n/r n/r n/r
Specularity Specular level 0 0 0 0 50 0
Diffuse Soften 0 0 0 0 0 0
Roughness Glossiness 0 0 0 0 0 0
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Shader 2 sided 2 sided 2 sided 2 sided
2
sided
2 sided
Self
illumination
-
n/a n/a n/a n/a n/a n/a
Opacity Opacity 100 100 100 100 100 100
Transmittance - n/a n/a n/a n/a n/a n/a
Refractive
Index
Luminance glow
0 0 0 0 0 0
Material
Texture
Texture Map u/s u/s
u/s u/s
u/s u/s

Bounce
coefficient
1
1 1 1 1 1

161
Table - 36: (continued..)

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Light
calculation
Exposure control
Luminance/
Illuminance
n/r n/r n/r n/r n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20186.IES) equivalent.
Daylighting Daylighting u/s ( no )
Luminance rating n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties
Table - 37: Material properties for 50% material reflectance properties in 3D studio max

For 50% Reflective Surface
Testing
Terminology
3D studio max
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance map
50
(assign)
n/r n/r n/r n/r n/r
Specularity Specular level 0 0 0 0 50 0
Diffuse Soften 0 0 0 0 0 0
Roughness Glossiness 0 0 0 0 0 0
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Shader 2 sided 2 sided 2 sided 2 sided
2
sided
2 sided
Self
illumination
-
n/a n/a n/a n/a n/a n/a
Opacity Opacity 100 100 100 100 100 100
Transmittance - n/a n/a n/a n/a n/a n/a
Refractive
Index
Luminance glow
0 0 0 0 0 0
Material
Texture
Texture Map u/s u/s
u/s u/s
u/s u/s

Bounce
coefficient
1
1 1 1 1 1

162
Table - 37: (continued..)

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Light
calculation
Exposure control
Luminance/
Illuminance
n/r n/r n/r n/r n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20186.IES) equivalent.
Daylighting Daylighting u/s ( no )
Luminance rating n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table - 38: Material properties for 0% material reflectance properties in 3D studio max

For 0% Reflective Surface

Testing
Terminology
3D studio max
Terminology
North
wall
South
wall
West
wall
East
wall
Floor Ceiling

Reflectance Reflectance map 0 (assign) n/r n/r n/r n/r n/r
Specularity Specular level 0 0 0 0 50 0
Diffuse Soften 0 0 0 0 0 0
Roughness Glossiness 0 0 0 0 0 0
Color bleed - n/a n/a n/a n/a n/a n/a
Surface
Orientation
Shader 2 sided 2 sided 2 sided 2 sided
2
sided
2 sided
Self
illumination
-
n/a n/a n/a n/a n/a n/a
Opacity Opacity 100 100 100 100 100 100
Transmittance - n/a n/a n/a n/a n/a n/a
Refractive
Index
Luminance glow
0 0 0 0 0 0
Material
Texture
Texture Map u/s u/s
u/s u/s
u/s u/s

Bounce
coefficient
1
1 1 1 1 1

163
Table - 38: (continued..)

Hue n/a n/a n/a n/a n/a n/a
Saturation n/a n/a n/a n/a n/a n/a Color Color
Value n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r n/r n/r n/r
n/r
Light
calculation
Exposure control
Luminance/
Illuminance
n/r n/r n/r n/r n/r

View Camera Position South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20186.IES) equivalent.
Daylighting Daylighting u/s ( no )
Luminance rating n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Tests:

Table - 39: Table of tests for reflectance in 3D studio max

TESTING PROPERTY Test-1 Test-2 Test-3

North Wall Reflectance 100% 50% 0%

Test anticipation:
Run tests with the specified artificial lamp.
Calculate the amount of light arriving the surface at the centre of the wall where the lamp
is aimed and compare it with the amount of light bouncing off the surface at that specific
point. For the 100% reflective surface the illuminance should be equal to exitance and for
the 50% reflective surface the exitance should be half the illuminance.

164

Results:

Fig C5.3.4.1: Illuminance output for test-1 in 3D studio max for reflectance test.

The above image shows the light being aimed on to the centre of the north
reflective wall though the lamp is not visible. The north wall has been assigned the
reflectivity as 100 and the reflective/raytrace map has been assigned to perform the
reflectivity test on the above specified lighting software program. The illuminance scale
in the image is for the amount of light being received on the surface of the north wall.
The north wall receives light more then 270lux and for the 100% reflective surface, we
expect all the light to reflect from the north wall. Hence the luminance plot should show
the light values (luminance) less then or equal to half the value received on the surface.
The fig C5.3.4.2 shows the luminance plot for the above specified test.

165

Fig C5.3.4.2: Luminance output for test-1 in 3D studio max for reflectance test.

The amount of light leaving the north wall surface (luminance) is between
178cd/m2 to 224.10 cd/m2. This value of luminance is close to half the illuminance. The
tests are performed for the 50% reflectance properties of the north wall. Let’s look into
the test results of the 50 % reflectance and the 0% reflectance tests. All the views in the
following tests were fixed at south east isometric view which makes it easy for the
readers to read and understand the test results. The Lamps are invisible in that analysis as
the above lighting software program doesn’t show the fixtures in the rendered images as
already noted in the specularity tests before.

166

Fig C5.3.4.3: Illuminance output for test-2 in 3D studio max for reflectance test.

The above image shows the illuminance plot for the 50% reflectance test. The
illuminance at the centre of the north reflective wall for 50% reflectance property is
above 270 lux. This value is almost the same as that in the case of the 100 % reflective
wall.
The image below shows the luminance plot for the 50% reflectance test ( test-2).
The plot for the 50% reflectance resembles the same as the luminance of 100%
reflectance test. The luminance for the 100% north reflective wall is twice the luminance
of 50% reflective wall surface. But in the present case we see both the tests showing the
same amount of luminance.

167

Fig C5.3.4.4: Luminance output for test-2 in 3D studio max for reflectance test.

The results from the tests show that the luminance for the 50% case and the 100%
case is the same. The test results show no variation in the light values reflecting off the
north wall. The test-3 is with the wall surface having the 0% reflectance meaning that no
light is reflected off the north wall. Hence the luminance from the north wall has to be
almost close to 0 cd/m
2
. The tests are performed and the image below shows the
illuminance and the luminance color coded plot of test – 3.
In all the three cases the illuminance plot is the same as expected, but the
luminance has to change with the change in the material reflectance property of the north
wall onto which we have aimed the lamp to cast the light at the centre of the wall.

168
The illuminance plot is expected to show the traces of red color on the floor
reflected off the floor. This is somewhat similar to the specularity test but the light on the
floor has to be more diffused unlike the sharp light patch as in the case of the specularity
test. Unfortunately there is no light seen on the floor as being reflected from north wall.

Fig C5.3.4.5: Illuminance output for test-3 in 3D studio max for reflectance test.

169

Fig C5.3.4-6: Luminance output for test-3 in 3D studio max for reflectance test.

Hence it can be concluded that the 3D studio max – 8 has the capabilities to
render the color coded plots for the illuminance and the luminance, but the plot remains
the same for any time of reflective material. This value remains constant to the case of
the 100% reflective properties of the material.

Therefore the lighting software 3D Studio Max – 8 has failed to perform accurate, the
reflectance test assigned by us.

170
TRANSMITTANCE TEST

This chapter explains about the process followed for testing the transmittance
property of the materials in the four Lighting design software program that were selected
for testing. These four Lighting design software program are Lightscape, AGI, 3D Studio
Max-8 and Desktop Radiance which passed through the screening process for identifying
the various available effective Lighting design software program. This test looks little
similar to the previous test of reflectance test performed.
Transmission is a characteristic of many materials like glass, plastic, etc, which is
the ratio of the total emitted light to the total incident light. The two prime factors which
affect the transmittance property of a material are reflections at each surface of the
material and absorption with in the material. The transmittive property of a material can
be categorized as diffuse transmission and mixed transmission. Diffuse transmission is a
result of diffuse material scattering light in all directions where as mixed transmission is a
result of a spectrally selective diffusion characteristic exhibited by certain materials such
as fine opal glass etc.
The room dimension measures the same and will be having three lamps
positioned as in the case for the reflectance test. We are actually trying to test the
Lighting design software program with the least number of parameters possible in the
testing so that the results can be analyzed accurately and trouble shooting the problem
will be very easy. In the present case, the room has no glazing or openings.

171
DRAWING LAYOUT FOR TRANSMITTANCE TESTING

Fig C5.4.1: Room plan with fixture layout and labeling.

Fig C5.4.2: Room cross section - AA` with fixture layout and labeling.

172

TEST FOR TRANSMITTANCE

Software: AGI

Definition: The transmissivity is the fraction of the light falling on one side of the
surface that passes through the material and leaves the other surface. It is sometimes
expressed as a percentage.

Model: Create a room of size 40’x20’x20’. Aim the lamps X onto the centre of the
North wall as shown in Fig C5.4-1 and Fig C5.4-2.

Material Properties

Table – 40. Material table for 100% transmittance property of wall in AGI

For 100% transmittive surface
Testing
Terminolog
y
AGI
Terminology
North
Wall - A
North
Wall - B
Sout
h
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance Reflectance 0 0 0 0 0 0 0
Specularity Specularity 0 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a n/a
Roughness n/a n/a n/a n/a n/a n/a n/a
Color bleed Color Bleed 0 0 0 0 0 0 0
Surface
Orientation
Surface Type
20-
Transition
Window
(transpare
nt)
Single-
Sided
Singl
e-
Sided
Singl
e-
Sided
Singl
e-
Sided
Singl
e-
Sided
Single
-Sided
Self
illumination
- n/a n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a n/a
Transmittan
ce
Transmittance 1 0 n/a n/a n/a n/a n/a

173

Table – 40. (continued..)

Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name n/a n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None None

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Colo
r
Value n/a n/a n/a n/a n/a n/a n/a

Points on
surface
Normal
Side
(Front/Top)
Normal
Side
(Front/Top)
n/r n/r n/r n/r n/r

Light meter
type
Normal to
Surface
Normal to
Surface
n/r n/r n/r n/r n/r
Light-sensor
grid
Grid spacing 1x1
1x1
n/r n/r n/r n/r n/r

Calculation
type
Illuminanc
e
Illuminan
ce
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

174
Material Properties

Table – 41. Material table for 50% transmittance property of wall in AGI

For 50% transmittive surface
Testing
Terminolog
y
AGI
Terminology
North
Wall - A
North
Wall - B
South
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance Reflectance 0 0 0 0 0 0 0
Specularity Specularity 0 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a n/a
Roughness n/a n/a n/a n/a n/a n/a n/a
Color bleed Color Bleed 1 1 1 1 1 1 1
Surface
Orientation
Surface Type
20-
Transition
Window
Single-
Sided
Singl
e-
Sided
Singl
e-
Sided
Singl
e-
Sided
Singl
e-
Sided
Singl
e-
Sided
Self
illumination
- n/a n/a n/a n/a n/a n/a n/a
Opacity - n/a n/a n/a n/a n/a n/a n/a
Transmittan
ce
Transmittance 0.5 0 n/a n/a n/a n/a n/a
Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name n/a n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None None

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Colo
r
Value n/a n/a n/a n/a n/a n/a n/a

Points on
surface
Normal
Side
(Front/Top)
Normal
Side
(Front/Top)
n/r n/r n/r n/r n/r

Light meter
type
Normal to
Surface
Normal to
Surface
n/r n/r n/r n/r n/r
Light-sensor
grid
Grid spacing 1x1
1x1
n/r n/r n/r n/r n/r

Calculation
type
Illuminanc
e
Illuminan
ce
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -

Luminance
rating
n/a

175
Tests:
Table – 42. Test criteria for North wall transmittance in AGI

Test-1 Test-2

North Wall –A
Transmittance
100% 50%

Test anticipation:
Run tests with the specified artificial lamp.
Calculate the amount of light arriving the surface at the centre of the transmittive wall
(Wall-A) where the lamp is aimed onto and compare it with the amount of light measured
on the surface of another wall (Wall-B) just behind this transmittive wall surface, where
the light beam normal from the lamp passing through the transmittive wall-A falls onto
the wall-B. Assign no transparency to the wall B. For the 100% transmittive surface the
illuminance on (Wall-B) should be almost equal to or slightly less then the illuminance
on Wall-A and for the 50% transmittance surface, the illuminance on Wall-B should be
half or slightly less then half the illuminance values received at the centre of the of the
North transmittive wall surface (Wall-A).

Results:
The tests were performed as demonstrated and the test results are ready for analysis. In
the lighting design software program AGI the north wall-A is labeled as Room_Wall_3
which is the transmittive wall, and the North wall-B which is the solid non transparent
wall is placed at a distance less then 1 foot away from the wall-A. The wall-B has been
labeled as Object_Side_3.

176

Fig C5.4.1.1: Transmittance test for 100% transitivity property.

The 100% transmittive surface (wall-A) has the maximum illuminance of 37.7 fc
in the centre of the north wall-A. The light passing through the north transmittive value
has the maximum illuminance value of 35.9 fc on the wall-B. The test results look the
same as we anticipated. Since the wall-B was placed little away from the wall-A, and
since the light is passing through a surface, so we can assume the transmission losses
through the medium and the distance factor for the reduction in the intensity of the light
transmission. Looking through the present case, we can expect that the 50% transmittive
wall (wall-A) can allow the 50% of the light to pass through it and record an illuminance
values (on wall-B) of half the amount recorded on the wall-A. The tests are further
carried with the 50% transmittive wall surface and the testing conditions are adjusted to
suit the requirements.

177

Fig C5.4.1.2: Transmittance test for 50% transitivity property.

The wall – A is made the 50% transmittive and the lamp is aimed from the centre
of the ceiling on the centre of the north wall – A. The lamp used is the VNSP (very
narrow spot) and the beam angle is 7°. The analysis window shows the north wall – A
(Room_Wall_3) has the maximum value recorded as 37.7 fc which is the illuminance
level from the lamp on the surface of the wall. The illuminance value on the wall – B
(Object_Side_3) has recorded the maximum illuminance value of 35.9 fc. The
illuminance values recorded for 100% transmittance surface is the same as the one for the
50% transmittance surface which hints us to recheck the test and the material properties
assigned.

178
The tests were re-performed but the new output results remained the same. This
looks more like a bug in this software program which has to be rectified considering the
process that I performed were appropriate. If there is any other method to be followed,
then I think that the manufacturers/ designers of this software program should state it
very clearly and it has to be very bold and open for the users to understand. In order to
check the method which other lighting designers are following for such cases, the testing
requirements were explained to a lighting designer who uses this software program in an
architectural lighting firm. He has good knowledge on the use of this software program.
The outputs of his test are as follows which he performed for the space with a
transparent window and also the case where the surface itself bears the transparency
property according to the test mentioned. Let’s see what his results say from the tests.

Fig C5.4.1.3: Transmittance test for 50% transitivity property by a professional.

179
This test was performed by a lighting professional who chose a room of 20’x20’
and has run the tests with walls of 1% reflectance. The wall-A is 50% transmittive and
the wall-B (Object_2_Side_4) is non-transmittive surface. If we read the analysis report,
it shows that the wall-A has the maximum illumination of 29.5 fc at the centre of the wall
and hence we can image that the wall-B should have the illumination less then or equal to
half the value on the wall-A. To the surprise the maximum illumination on wall-B is out
of imagination. The wall-B recorded the illumination level as 42.4 fc, which is higher
then the amount of light incident on the wall-A. This is more than a miracle in the fantasy
world but in reality this is not possible in the present time. This is certainly a bad bug in
the AGI software program.

Just to confirm the testing appropriateness, we have decided to place a window on the
wall-A surface and want to shoot the light through it on the wall-B behind the window.
Even in this case the wall-A has the window which was assigned 50% transmittive
property.

Counter checking the tests:
The test analysis was performed and everyone in the team wishes for it to be
appropriate and successful. Being the lighting designers, we were using this software
program and would be very pleased if this program passes the test successful. We have
used this program and designed many projects. If we look into the Fig C5.4-6, it shows
the illuminance values of wall-A (Room_Wall_2) and the wall-B (Object_Side_4).

180
The illuminance maximum on wall – A is 29.2 fc and the illuminance maximum on wall
– B is 29.2 fc. This is to be noted that the window was having 50% transmittance
property, which mean only half the amount of light will be able to pass through the
window pane. Hence practically if 29.2 fc is incident on the centre of the pane then not
more then 14.6 fc can be available on the wall behind the window (wall – B).

Adjusting parameters to check the software program:
The test was also performed by varying the reflectance values of the materials and
still the final light values (illuminance) output from the software program weren’t able to
pass the transmittance test. The final results were very inconsistent to compare due to
which the process of evaluating the cause or the fudge factor is also very difficult. It
seemed as if the whole of the algorithm of the light values through openings is
inappropriate and the error is more than the possible acceptance range. The value of
maximum illuminance that passed through the window is greater than that incident on the
window pane according to the test results. We were all left out pale after seeing the test
outputs.
This certainly gives a much emphasis on the conventional rule of thumb methods
which are not very accurate but still can help us analyze the spaces at a much faster and
easy way without the help of computers and software programs. There is always a
confusion between which is better, a lighting software program or a conventional rule of
thumb knowledge. There is never a clear answer for such questions which basically vary
from person to person. Its all depend upon the convenience of a person using them.

181

Fig C5.4.1.4: Transmittance test for 50% transitivity property by a professional.

Hence the AGI lighting design software program was not able to provide the
correct and accurate outputs for the transmittance test after assigning the above
mentioned task (test of transmittance). The values are very consistent for every new test
with the same parameters of the previous tests. The values are not accurate enough to be
considered with any fudge value. Users need to take extra care wile using this type
configuration for the analysis.

182

TEST FOR TRANSMITTANCE

Software: DESKTOP RADIANCE

DEFINITION: The transmissivity is the fraction of the light falling on one side of
the surface that passes through the material and leaves the other surface. It is sometimes
expressed as a percentage.

MODEL: Create a room of size 40’x20’x20’. Aim the lamps X onto the
centre of the North wall as shown in Fig C5.4-1 and Fig C5.4-2.

Material Properties

Table 43. Material table for 50% transmittance property of wall in Desktop Radiance

For 50% transmittive surface
Testing
Terminology
Desktop
Radiance
Terminology
North
Wall -
A
North
Wall -
B
South
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance Reflectance (%) 7.8% 1.88%
1.88
%
1.88% 1.88%
0 0
Specularity Shininess (%) 0 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a n/a
Glossiness Roughness (%) n/a n/a n/a n/a n/a n/a n/a
Roughness - n/a 0 0 0 0 0 0
Color bleed
Surface
Orientation
0 0 0 0 0 0 0
Surface
Orientation
- Interior Interior
Interi
or
Interio
r
Interior Interior
Interio
r
Self
illumination
- n/a n/a n/a n/a n/a n/a n/a
Opacity
Transparency
(%)
n/a n/a n/a n/a n/a n/a n/a
Transmittan
ce
Refractive
Index
55.1% 0 0
0 0 0 0
Refractive
Index
Material Name
n/a n/a n/a n/a n/a n/a n/a

183
Table – 43 (continued..)

Material
Texture
Procedural
texture
Dup-
Brn_Lit
e
RAL90
05_Jet_
black
RAL9
005_J
et_bla
ck
RAL9
005_J
et_bla
ck
RAL90
05_Jet_
black
RAL90
05_Jet
_black
RAL9
005_J
et_bla
ck
Texture None None None None None None None

Hue n/a n/a n/a n/a n/a n/a n/a
Saturatio
n
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r
Calculation type
Illumin
ance
Illumin
ance
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table 44. Material table for 100% transmittance property of wall in Desktop Radiance

For 100% transmittive surface
Testing
Terminology
Desktop
Radiance
Terminology
North
Wall -
A
North
Wall -
B
South
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance Reflectance (%) 10% 1.88%
1.88
%
1.88% 1.88%
0 0
Specularity Shininess (%) 0 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a n/a
Glossiness Roughness (%) n/a n/a n/a n/a n/a n/a n/a
Roughness - n/a 0 0 0 0 0 0
Color bleed
Surface
Orientation
0 0 0 0 0 0 0

184
Table 44. (continued..)

Surface
Orientation
- Interior Interior
Interi
or
Interio
r
Interior Interior
Interio
r
Self
illumination
- n/a n/a n/a n/a n/a n/a n/a
Opacity
Transparency
(%)
n/a n/a n/a n/a n/a n/a n/a
Transmittan
ce
Refractive
Index
100% 0 0
0 0 0 0
Refractive
Index
Material Name
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Procedural
texture
Special
Illum
RAL90
05_Jet_
black
RAL9
005_J
et_bla
ck
RAL9
005_J
et_bla
ck
RAL90
05_Jet_
black
RAL90
05_Jet
_black
RAL9
005_J
et_bla
ck
Texture None None None None None None None

Hue n/a n/a n/a n/a n/a n/a n/a
Saturatio
n
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r
Calculation type
Illumin
ance
Illumin
ance
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

TESTS:

Table 45. Test criteria for North wall transmittance in Desktop Radiance

Test-1 Test-2

North Wall Transmittance 100% 50%

185

TEST ANTICIPATION:

Calculate the amount of light arriving the surface at the centre of the transmittive
wall (Wall-A) where the lamp is aimed onto and compare it with the amount of light
measured on the surface of another wall (Wall-B) just behind this transmittive wall
surface, where the light beam normal from the lamp passing through the transmittive
wall-A falls onto the wall-B. Assign no transparency to the wall B. For the 100%
transmittive surface the illuminance on (Wall-B) should be almost equal to or slightly
less then the illuminance on Wall-A and for the 50% transmittance surface, the
illuminance on Wall-B should be half or slightly less then half the illuminance values
received at the centre of the of the North transmittive wall surface (Wall-A).

Fig C5.4.2.1: Simulation model for the transparency test in Desktop Radiance.

186

Fig C5.4.2.2: Model in winrview window for transparency test in Desktop Radiance.

RESULTS:

The tests were performed with the above specifications as shown in the table. The Test-1
is with the Wall-A having the 100% transmittance and the Test -2 is with the Wall-A
having the 50% transmittance. The Wall-B in both the test has the transmittance as zero.
The output from the simulation manager is shown in the figures. The value of
illuminance is marked in the red box as we see in the image below.

187

Fig C5.4.2.3: Test-1 on wall-A for 100% wall transparency.

For the North wall-A having the transmittance of 100%, the value of illuminance
at the centre of wall-A is 923 fc, and the value of illuminance at the centre of wall-B is
909 fc. Comparing the illuminance values at the centre of the Wall-A and Wall-B shows
that the transmission of light through the glazing is almost complete.

188

Fig C5.4.2.4: Test-1 on wall-B for 100% wall transparency.

For the next case, with the test-2 where the wall-A is 50% transmittive, the
illuminance values are shown below. The image below shows the simulation manager
results. The test performed is designated as test-2, which is also the south west isometric
view. The transparency is applied on wall-A for a transparency property of 50%.

189

Fig C5.4.2.5: Test-2 on wall-A for 50% wall transparency.

The Illuminance at the centre of wall-A for the case of 50% transmittance properties of
wall-B shows the output as 923 fc and the value of illuminance at the centre of wall-B is
455 fc. This value is almost close to half the value of illuminance on wall-A. Hence the
amount of light that is cast on the surface of the wall-B is half the value of the amount of
illuminance that was on the wall-A which is 50% transmittive surface.

190

Fig C5.4.2-6: Test-2 on wall-B for 50% wall transparency.

It can be concluded from the above test on transmittance that the software program
Desktop Radiance performs well for the transmissive properties of the materials.
Hence this program passed the transmittance test successfully.

191

TEST FOR TRANSMITTANCE

Software: Lightscape

DEFINITION: The transmissivity is the fraction of the light falling on one side of
the surface that passes through the material and leaves the other surface. It is sometimes
expressed as a percentage.

MODEL: Create a room of size 40’x20’x20’. Aim the lamps X onto the
centre of the North wall as shown in Fig C5.4-1 and Fig C5.4-2.

Material Properties

Table 46. Material table for 100% transmittance property of wall in Lightscape.

For 100% transmittive surface
Testing
Terminology
Lightscape
Terminology
North
Wall -
A
North
Wall -
B
Sout
h
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance Reflectance 0/2 0/2 0/2 0/2 0/2 0/2 0/2
Specularity Specularity 0 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a n/a
Roughness n/a n/a n/a n/a n/a n/a n/a
Color bleed Color Bleed 0 0 0 0 0 0 0
Surface
Orientation
Surface Type
Toward
inside
Toward
inside
Towa
rd
inside
Toward
inside
Toward
inside
Towar
d
inside
Towar
d
inside
Self
illumination
Luminance
glow
0 0 0 0 0 0 0
Opacity - n/a n/a n/a n/a n/a n/a n/a
Transmittan
ce
Transmittance 1 0 n/r n/r n/r n/r n/r
Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a n/a

192
Table 46. (continued..)

Material
Texture
Material Name n/a n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None None

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r

Calculation
type
Illumin
ance
Illumina
nce
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table 47. Material table for 50% transmittance property of wall in Lightscape.

For 50% transmittive surface
Testing
Terminology
Lightscape
Terminology
North
Wall - A
North
Wall -
B
South
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance Reflectance 0/2 0/2 0/2 0/2 0/2 0/2 0/2
Specularity Specularity 0 0 0 0 0 0 0
Diffuse - n/a n/a n/a n/a n/a n/a n/a
Glossiness - n/a n/a n/a n/a n/a n/a n/a
Roughness n/a n/a n/a n/a n/a n/a n/a
Color bleed Color Bleed 1 1 1 1 1 1 1
Surface
Orientation
Surface Type
Towards
inside
Toward
inside
Towa
rd
inside
Towar
ds
inside
Toward
s
inside
Towar
ds
inside
Towar
ds
inside

193
Table 47. Material table for 50% transmittance property of wall in Lightscape.

Self
illumination
Luminance
glow
0
0 0 0 0 0
0
Opacity - n/a n/a n/a n/a n/a n/a n/a
Transmittan
ce
Transmittance 0.5 0
n/r n/r n/r n/r n/r
Refractive
Index
Refractive
Index
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Material Name n/a n/a n/a
n/a n/a
n/a n/a
Texture None None None None None None None

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r

Calculation
type
Illumina
nce
Illumin
ance
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES).
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

TESTS:

Test-1 Test-2

North Wall –A
Transmittance
100% 50%
Table 48. Test criteria for North wall transmittance in Lightscape.

194
TEST ANTICIPATION:

Run tests with the specified artificial lamp.
Calculate the amount of light arriving the surface at the centre of the transmittive wall
(Wall-A) where the lamp is aimed onto and compare it with the amount of light
measured on the surface of another wall (Wall-B) just behind this transmittive wall
surface, where the light beam normal from the lamp passing through the transmittive
wall-A falls onto the wall-B. Assign no transparency to the wall B. For the 100%
transmittive surface the illuminance on (Wall-B) should be almost equal to or slightly
less then the illuminance on Wall-A and for the 50% transmittance surface, the
illuminance on Wall-B should be half or slightly less then half the illuminance values
received at the centre of the of the North transmittive wall surface (Wall-A).

RESULTS:
The tests are being performed for three cases with 0% transmittance, 50%
transmittance and 100% transmittance. The images are shown below which are
simulated for the comparison. The values of the illuminance are highlighted with the
red colored box for the sake of identification to be very easy.
Shown below are the simulation rendered images from the Lightscape
software program. The image – 1 shows the illuminance value at the point in the
centre of the north wall – A and the image – 2 shows the illuminance value at the
centre of the north wall – B.

195

Fig C5.4.3.1: Test-1 on wall-A for 0% wall transparency in Lightscape.

The value of illuminance at the centre of the north wall – A arriving from
the lamp is 44269.5 lux. The sensor is placed to record the light value arriving at this
point for all the three cases and the value of illuminance is recorded with out varying
the position of the sensor. Similar sensor is placed on the wall – B which records the
illuminance values arriving the surface passing through the glazing (north wall – A).
This test is performed for 0% transparency, i.e the wall – A is 0% transparent
meaning that the wall – A doesn’t allow any light to pass through it to be cast on wall
– B. Hence the surface (wall – A) is opaque for the present testing case. We are
anticipating that no light pass through the wall – A and thereby no light should be cast
on the wall – B which is placed behind the wall – A.

196
Let us look into the simulation output and the light values recorded by the
sensors on the wall – B. The simulation results for the particular case are shown in
image – 2.

Fig C5.4.3.2: Test-1 on wall-B for 0% wall transparency in Lightscape.

The value on the north wall – B is recorded as 1.7 lux. This value of
illuminance can be considered to be almost equal to 0%. Thought for the ideal
condition this value should be recorded as 0%, but considering certain conditions on
the part of the light software programs, these values are many times visible. Theses
values may be due to the light leak from the corners of the surfaces or due to the
algorithm of the software program of could be any reason which can be neglected.

197

Fig C5.4.3.3: Test-1 on wall-B for 0% wall transparency in Lightscape.

Looking into this situation the amount of light cast on the wall – A at its
centre is 44269.5 lux and the light that is cast on the wall – B passing through the
surface (wall – A) lying in front of it which is opaque records 0.0 lux. Hence it can be
concluded from the above two images that for the case of 0% transmittance of wall –
A, there is no light passing through it.
Now lets look into the second case where the wall – A is 100%
transmittance in property. Hence the light cast on one of its side is allowed to pass
through it completely with out any obstruction. The value on wall – A should be the
same as the value of illuminance on wall – B. The simulations for the 100%
transmittance property of the wall – A is performed and the parameters assigned are
noted in the table of the material properties as shown above.

198

Fig C5.4.3.4: Test-1 on wall-A for 100% wall transparency in Lightscape.

The above image – 3 is the simulation output for the test – 1 performed.
The amount of light arriving at the centre of the north wall – A surface is 44318.2 lux.
The test anticipation is to find the same amount of illuminance or slight less then the
above value to be recorded at the near centre of the wall – B. The value of the
illuminance recorded by the light sensors placed on the wall – B is shown in image –
4 that received 37349.5 lux. This value of illuminance is almost close to the amount
of light that arrived the wall surface – A. Since the two walls are placed little far
apart, so there is the light loss (illuminance) during the propagation.

199

Fig C5.4.3.5: Test-1 on wall-B for 100% wall transparency in Lightscape.

The 100% transmittance surface is able to perform as anticipated and can
be considered as good performance. The light sensor on wall – A has recorded the
illuminance as 44318.2lux and the sensor on wall – B has recorded the value of
illuminance as 37349.5lux. Hence this lighting software program has performed the
Test - 1 successfully and has rendered the appropriate values as anticipated.
Lets look into the third case where the surface is 50% transmittive in
property and this is named as Test – 2. In the Test – 2, the wall – A is 50%
transmittive in property and the wall – B is 0% transmittive. The testing procedure
and the model is the same except that the values of the transmittive property of the
wall – A is modified to half.

200
Since the wall – A is 50 % transmittive, we are anticipating that half the
amount of light will be able to pass through the wall surface–A and is cast on the wall
surface–B.
The image – 5 shows the amount of illuminance that arrived on to the
centre of the north transmittive wall – A from the lamp.

Fig C5.4.3.6: Test-2 on wall-A for 50% wall transparency in Lightscape.

The above image – 5 is the case where the light sensors are placed on the
surface of the wall – A. It shows that the wall – A has received the 44291.8 lux of
illuminance at the centre of the wall. This is the test case for the 50% transmittance
property of wall – A. The image – 6 is the simulation output for the test – 2 with the
sensors placed on the wall – B.

201
The value of illuminance received on the surface of the wall – B close to the centre of
the wall is 18684.9 lux. This value is almost close to half the value of illuminance at
the centre of the north wall – A. As stated earlier that the value of illuminance on
north wall – B is either half the value of illuminance or is slightly less then half the
value of illuminance recorded on the wall – A. In the present test – 2 the illuminance
on the wall – B is slightly less then half the value of illuminance on wall – A.

Fig C5.4.3.7: Test-2 on wall-B for 50% wall transparency in Lightscape.

There by looking into all three above tests, one can infer that the lighting
software program Lightscape is able to perform well as anticipated and the out put
results are close to the approximation.

202

TEST FOR TRANSMITTANCE
Software: 3D STUDIO MAX – 8

DEFINITION: The transmissivity is the fraction of the light falling on one side of
the surface that passes through the material and leaves the other surface. It is sometimes
expressed as a percentage.

MODEL: Create a room of size 40’x20’x20’. Aim the lamps X onto the
centre of the North wall as shown in Fig C5.4-1 and Fig C5.4-2.

Material Properties

Table 49. Material table for 100% transmittance property of wall in 3D Studio Max-8

For 100% transmittive surface
Testing
Terminology
3D Studio
Max-8
Terminology
North
Wall -
A
North
Wall -
B
Sout
h
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance
Reflectance/rayt
race
select select select select select select select
Specularity Specular level 0 0 0 0 0 0 0
Diffuse Soften 0 0 0 0 0 0 0
Glossiness Glossiness 0 0 0 0 0 0 0
Roughness - n/a n/a n/a n/a n/a n/a n/a
Color bleed - 0 0 0 0 0 0 0
Surface
Orientation
Shader
2 Sided 2 Sided 2
Sided
2 Sided 2 Sided 2 Sided 2
Sided
Self
illumination
Luminance
glow
0
0 0 0 0 0
0
Opacity Opacity 0 100 0 0 0 0 0
Transmittan
ce
- n/a
n/a n/a n/a n/a n/a n/a
Refractive
Index
-
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Texture Map
u/s u/s u/s u/s u/s u/s u/s

Bounce
coefficient
1 1 1 1 1 1 1

203
Table 49. (continued..)

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r

Calculation
type
Illumin
ance
Illumina
nce
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES) or equivalent.
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

Material Properties

Table 50. Material table for 50% transmittance property of wall in 3D Studio Max-8

For 50% TRANSMITTIVE SURFACE
Testing
Terminology
3D Studio
Max-8
Terminology
North
Wall -
A
North
Wall -
B
Sout
h
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance
Reflectance/rayt
race
select select select select select select select
Specularity Specular level 0 0 0 0 0 0 0
Diffuse Soften 0 0 0 0 0 0 0
Glossiness Glossiness 0 0 0 0 0 0 0
Roughness - n/a n/a n/a n/a n/a n/a n/a
Color bleed - 0 0 0 0 0 0 0
Surface
Orientation
Shader
2 Sided 2 Sided 2
Sided
2 Sided 2 Sided 2 Sided 2
Sided

204
Table 50. (continued..)

Self
illumination
Luminance
glow
0
0 0 0 0 0
0
Opacity Opacity 50 100 0 0 0 0 0
Transmittan
ce
-
n/a n/a n/a n/a n/a n/a n/a
Refractive
Index
-
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Texture Map
u/s u/s u/s u/s u/s u/s u/s

Bounce
coefficient
1 1 1 1 1 1 1

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r

Calculation
type
Illumin
ance
Illumina
nce
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES) or equivalent.
Daylighting Daylighting -

Luminance
rating
n/a

u/s
Unselect the option as we are not using these parameters in the present case
n/r
Not Required as we are not using these parameters in the present case
n/a
Not Available as the software doesn’t ask for these values in the present case

205

Material Properties

Table 51. Material table for 0% transmittance property of wall in 3D Studio Max-8.

For 0% transmittive surface
Testing
Terminology
3D Studio
Max-8
Terminology
North
Wall -
A
North
Wall -
B
Sout
h
Wall
West
Wall
East
Wall
Floor
Ceilin
g

Reflectance
Reflectance/rayt
race
select select select select select select select
Specularity Specular level 0 0 0 0 0 0 0
Diffuse Soften 0 0 0 0 0 0 0
Glossiness Glossiness 0 0 0 0 0 0 0
Roughness - n/a n/a n/a n/a n/a n/a n/a
Color bleed - 0 0 0 0 0 0 0
Surface
Orientation
Shader
2 Sided 2 Sided 2
Sided
2 Sided 2 Sided 2 Sided 2
Sided
Self
illumination
Luminance
glow
0
0 0 0 0 0
0
Opacity Opacity 100 100 0 0 0 0 0
Transmittan
ce
-
n/a n/a n/a n/a n/a n/a n/a
Refractive
Index
-
n/a n/a n/a n/a n/a n/a n/a
Material
Texture
Texture Map
u/s u/s u/s u/s u/s u/s u/s

Bounce
coefficient
1 1 1 1 1 1 1

Hue n/a n/a n/a n/a n/a n/a n/a
Saturati
on
n/a n/a n/a n/a n/a n/a n/a
Color
Col
or
Value n/a n/a n/a n/a n/a n/a n/a

Light-sensor
grid
Grid spacing
n/r n/r
n/r n/r n/r n/r n/r

Calculation
type
Illumin
ance
Illumina
nce
n/r n/r n/r n/r n/r

Calculation
points
On
On
Off Off Off Off Off

View Camera
Position
South east isometric view.
Lamp
specification
Lamp type MR16 – VNSP - 7° (GE Lighting – 20816.IES) or equivalent.
Daylighting Daylighting -

Luminance
rating
n/a

206

TESTS:

Table 52. Test criteria for North wall transmittance in 3D Studio Max-8.

TESTING PROPERTY Test-0 Test-1 Test-2

North Wall –A Transmittance 0% 100% 50%

TEST ANTICIPATION:

Run tests with the specified artificial lamp.
Calculate the amount of light arriving the surface at the centre of the transmittive wall
(Wall-A) where the lamp is aimed onto and compare it with the amount of light
measured on the surface of another wall (Wall-B) just behind this transmittive wall
surface, where the light beam normal from the lamp passing through the transmittive
wall-A falls onto the wall-B. Assign no transparency to the wall B. For the 100%
transmittive surface the illuminance on (Wall-B) should be almost equal to or slightly
less then the illuminance on Wall-A and for the 50% transmittance surface, the
illuminance on Wall-B should be half or slightly less then half the illuminance values
received at the centre of the of the North transmittive wall surface (Wall-A).

RESULTS:
The tests are being performed for three cases with 0% transmittance, 50%
transmittance and 100% transmittance. The images are shown below which are
simulated for the comparison. The values of the illuminance are highlighted with the
red colored box for the sake of identification to be very easy.

207
Shown below are the simulation rendered images from the 3D Studio max
-8 software program. The image – 1 shows the illuminance value at the point in the
centre of the north wall – A and the image – 2 shows the illuminance value on north
wall – B.

Fig C5.4.4.1: Test-1 for 100% wall transparency in 3D studio max-7.

The above plot is the perspective image generated by the lighting software
program 3D-Studio Max 8. In the above image we see that for the 100% transparency
test (Test-1), the light from the lamp is able to pass through wall – A and cast beam
on wall – B. The value of illuminance on both the walls looks almost the same.

208
Since the wall – B is little farther away from wall – A but still the light level
(illuminance) reduction doesn’t seem to be much. The wall – B is placed little farther
away so as to facilitate the visibility of the light being cast on both the wall and to
read the illuminance color coding image on the surfaces and by this way we don’t
change the orientation of the model to be more consistent with the testing angle.

Fig C5.4.4.2: Test-1 for 100% wall transparency in 3D studio max-7.

In this image for 100% transparency test, we see that the illuminance plot
has the same amount of illuminance on both the walls A and B. This is true and
accurate for the case of 100% transparent surfaces. Now we have to look into the next
set of tests (Test-2) to further analyze the test results on transmittance.

209
The image below is for the case of 50% transmittance test where the wall
– A is 50% transparent and the wall – B is 0 % transparent. Lets look into the output
renderings by the software program below.

Fig C5.4.4.3: Test-2 for 50% wall transparency in 3D studio max-7.

The image above shows the raytrace perspective plot for the 50%
transmittive wall – A. We see that the wall – B which is 0 % transmittive has the
higher level of illuminance marked on it and the wall – A has the lesser amount of
illuminance recorded on it surface. Let us also look into the illuminance plot
generated by this program to compare it with the perspective plot.

210
The illuminance plot generated by the software program (3D Studio max) for the
above 50% transmittive test (test-2) is shown below. This software program generates
so many different types of images like one for perspective and one for illuminance
etc, makes very confusing to compare on as both of them are color coded images but
they are not similar thought the output is for the same testing parameters. This many
times will confuse the new users to select the right color coded graph to analyze their
test outputs.

Fig C5.4.4.4: Test-2 for 50% wall transparency in 3D studio max-7.

211
As we see in the above image for the 50% transmittance test (Test-2), the
illuminance plot and the perspective plot with the color coding graphing ON are not
the same. In the perspective plot for this test we saw that the illuminance on the wall
– B is higher then that on wall – A if we consider that the surface with red tones are
higher as shown in the legend for the illuminance plot generated by the software
program as shown above. Considering that, we can say that the illuminance on the
wall – A is almost equal to the illuminance recorded on wall – B. For the case of 50%
transmittive surface we expect that the wall – B should receive only the half of the
illuminance that has arrived on wall – A. The perspective plot for the above test – 2
specified completely contradicts our prediction.
The illuminance plot is almost similar to the one noticed in the 100%
transmittance test. Hence the final outputs for the transmittance test are away from the
range of expectation and acceptance. Just to confirm the test and being more curious
made me to run the test (test-0) with the surface (wall –A) having the transmittance as
0%. This is to see that if the wall – A is completely opaque and the wall – B is also
opaque, then what are the outputs that the program for the lighting (3D studiomax) is
about to generate.
The test images below shows the perspective and the illuminance plot for
the case having the wall – A to be completely opaque (0% transmittive). Lets look
into the final output renderings for the above case of 0% transmittance property.

212

Fig C5.4.4-5: Test-0 for 0% wall transparency in 3D studio max-7.

The above image is for the wall – A having the surface as 0% transmittive
and is the perspective plot. The image below shows the illuminance plot for the above
case. In both the cases the raytrace option is kept on.

213

Fig C5.4.4-6: Test-0 for 0% wall transparency in 3D studio max-7.

As we see in the above images of perspective and illuminance plots for the 0%
transmittive surfaces, the wall – B is recording the same amount of light passing through
the wall surface A. The wall A is opaque means that no light should pass through it and
the wall –B should have almost no light being recorded on its surface. But this test shows
that there is the same amount of light recorded as in the case with the other two tests
performed before for transmittance. Hence we can say that the software program (3D
Studio Max 8) is unable to perform well with the transmittance testing. For the amateur
users this is really tough for him to analyze the lighting values (illuminance and
luminance) as this program has some many controls on the parameters that people many
times by following the default general method can go wrong with their testing values.

214
As we recollect for the testing of the specularity in the same software program where we
encountered the fudge factor which was turning on the caustics to get the specular
bounces off the wall can always cause great trouble. If we are not very aware of this
program then the default methods as performed for many other software programs for
lighting, following the general rules, principles and method can always lead us to wrong
calculations. This program is so though to understand that some times it takes a lot of
valuable time to just understand and so this is not really so beautiful to use by the lighting
designers unless we are expert in this software program(3D Studio Max).

Hence it can be concluded that this program is not able to perform accurate for the
transmittance testing as specified by us.

SUMMARY OF TEST RESULT.

TESTING
SOFTWARE
SPECULARITY
(NATURAL)
SPECULARITY
( ARTIFICIAL)
REFLECTANCE TRANSMITTANCE

AGI FAILED FAILED PASSED FAILED

DESKTOP
RADIANCE
PASSED FAILED FAILED PASSED

LIGHTSCAPE PARTIAL PARTIAL PARTIAL PASSED

3D STUDIO
MAX-8
PASSED PASSED FAILED FAILED

Table 53. Summary of the test results of all four lighting software programs.
215
CHAPTER – 6.0

CONCLUSION

The test performed in the previous chapters will help us in exercising
caution while using the following lighting software programs. These lighting software
programs are broadly used by many lighting designers and their respective firms. The
rapid emergence of these lighting software programs gives little chance for the designers
to gain expertise in them. Some of the lighting software programs are old and a few are
new but in both the cases, some of the important lighting concepts are always not
properly incorporated. Some cases (like specularity) it is very clearly visible that some of
the bugs are still continuing even upto the present day. The new users in any lighting firm
will know very little about the lighting software programs and hence they will certainly
follow the general method as they use in the case of other lighting software programs to
simulate and analyze their models. Most of the lighting designers hardly have time to
analyze the software programs in depth to identify the bugs. Designers work in pace with
their projects and cannot spend a great deal of time and effort in understanding the
lighting software programs to their depth. I have spent considerable amount of time on
these lighting design software programs being tested in this thesis which can save the
time of readers in directly dealing with few of the issues. It can be assumed that if myself
was not able to understand the use of these lighting software programs even by this time,
then certainly the amateur users cannot understand it with their limited time and
knowledge on these lighting software programs who may have not spent that
considerable amount of time as I was able to which is all they could have.
216
Explaining about the tests in brief, the four lighting software programs that I have chosen
according to criteria of their utilization by the designers are:
1. AGI32-EDU-V1DOT8 version 1.84 copyright 1999-2005 by Lighting Analysts, Inc.
2. Desktop Radiance version 2.0 Beta 2 Build 33a (R15.0) Copyright 1998-2001
Marinsoft, Inc and Lawrence Berkeley National Laboratory.
3. 3D Studio Max version 8.0 Copyright 1997-2005 Autodesk, Inc.
4. Lightscape release 3.2 Build 76 licensed by 3name3d, santa monica, ca; artbeats
software, inc., myrtle creek, or; modern medium, inc. eugene, or; imagecels®
(texture files) copyright © 1987-1999 imagetects(tm).
The four tests that were assigned to evaluate these lighting software programs are
specularity test for both natural and artificial lighting, reflectance test and transmittance
test.
AGI32:
This lighting software program failed to show the specular reflections from a
highly specular surface. Instead it was showing the reflectance and was not the specular
bounce from the surfaces for both the artificial and natural light. This program was able
to perform the reflectance test successfully. It provided the appropriate values as
anticipated. The very odd part of this lighting software program was that it failed to
perform the transmittance test. The results were very vaguely different from the point of
consideration. The transmittance property of the materials is a very big bug in this
lighting software program. This lighting software programs is a commercial program sold
in the market. The bugs found here should be fixed in the new versions coming up. On an
average this program is easy to use and understand.
217

Desktop Radiance:
This lighting software program was initially very difficult to handle as it has no
considerable troubleshooting options for the errors occurred. It’s very tough to identify
the cause of the error and the program crashes with an error message which is very
difficult to understand for the amateur software users. Moreover this program needs the
support of AutoCAD to run and is not compatible with the latest versions of AutoCAD.
This lighting software program passed the specularity test for natural lighting but did not
do so with artificial lighting. It generated color coded plots and the iso-lumen plots
(images) for the artificial lighting specularity test which are very difficult to read and
analyze. This lighting software program was also not that successful in performing the
reflectance test. The transmittance test was successful and the results generated by this
program were good enough to be considered during the evaluation. On an overall scale
this lighting software program is not too difficult to be used in the lighting professional
firms as there is no technical support available and this is more of a research project
rather then a commercial lighting software program.

3D Studio Max-8:
This software program is a very good animation and graphic software program
which is trying to excel in the field of lighting too. This lighting software program is able
to perform the specularity test for both the natural and artificial lighting successfully. It
was able to produce the specular reflections from the surfaces except that it is easier to
tamper the whole graphics.
218
The specular reflections can be controlled and modified according to our desire
and hence there is always a greater scope for the user to fake the results from known
behavior than to rely on the program to provide accurate information. Moreover the
specular bounce off the surface by default is off in this software program and hence
unless users know about the concept of caustics in this graphic software program, the
results would never be correct. This lighting software program was not able to pass either
the reflectance test or the transmittance test. The reflectance test shows the same results
in color coded illuminance and luminance plots for whatever material reflectance
properties were assigned. In the transmittance test, the change in the material
transmittance doesn’t affect the amount of light passing through it and leaving the other
side of the surface. Though we see it visually that the surface looks translucent for 50%
transmittance property assigned and opaque for the 0% transparency assigned but the
color coded plots show the same amount of light in all the cases passing through it.
There may be a hidden unknown command to control this. But the amateur user who is
not highly professional in graphical design and who is more into lighting cannot
understand or identify it. Moreover we can consider that there is a fudge factor lying
within this process which makes analysis very difficult unless we master this lighting
software program completely. The higher level of concepts and large quantity of controls
makes it very tedious for users who rely on speed and time. This lighting software
program is more of a graphical design program and has a lot to do to overcome the
complexity of the program for the use of lighting designers. It would be great if this
lighting software is broken down into a new program and which is more directed towards
the lighting analysis and only the necessary and important concepts of graphics.
219
It will be of great comfort if they are made compatible with any of their other
designing software programs so that users can import them into other programs and
render the requirements. This will greatly help the amateur users with simple and
transparent commands to operate which saves time and increases the work efficiency.

Lightscape:
This lighting software program is no more in production. Many lighting designers
believe this lighting software program to be a successful and good program for lighting.
On an average this program performed fairly well. The specularity test with both the
natural and the artificial light was not entirely successful but it was moreover doing the
reflectance correctly. The reflectance test outputs were little strange as it was the
comparison between the illuminance and the luminance where the directional component
plays a big role, but the values seem to have a fudge factor. Though it was not a complete
failure, the results were not fully accurate. Except this lighting software program, no
other lighting software program tested exhibited this peculiar property. But on an average
we can consider this to be partially appropriate with the reflectance test. This lighting
design software program performed close to accurately as anticipated for the
transmittance test. Lightscape is also easy to use and the chance for the user to get
confused is much less. This lighting software program also has good graphic interface.

This summary is anticipated to help the readers to judge which lighting software
program should be used for some of the very important tests (analysis). This can also help
the users to identify the bugs present in these lighting software programs.

220
SUMMARY OF TEST RESULT.

TESTING
SOFTWARE
SPECULARITY
(NATURAL)
SPECULARITY
( ARTIFICIAL)
REFLECTANCE TRANSMITTANCE

AGI BELOW PARTIAL BELOW
PARTIAL
PASSED FAILED

DESKTOP
RADIANCE
PASSED
(POOR OUTPUT)
BELOW
PARTIAL
FAILED PASSED

LIGHTSCAPE
PARTIAL PARTIAL
ABOVE
PARTIAL
PASSED

3D STUDIO
MAX-8
PASSED
(FUDGED)
PASSED
(FUDGED)
FAILED FAILED

Table 54. Summary of the test results of all four lighting software programs.

LEGEND:

PASSED – If the lighting software program performs as anticipated and the test results
are as we expected.
ABOVE PARTIAL: If the lighting software programs test results are not as accurate as
anticipated but can be considered for analysis.
PARTIAL – If the lighting software programs test results are on an average away from
anticipation.
BELOW PARTIAL: If the lighting software programs test results are way away from
anticipation but still the program is performing the test with some fudge factor involved.
FAILED: If the lighting software programs results are completely inaccurate and the
results are of no use for any analysis or if the program is not performing the test.

221

CHAPTER 7.0
FUTURE WORK

This thesis topic is comparatively very vast and can be never-ending with new
research and development in the field of science and technology. A broad classification
of the future work can be categorized as:
• Running new and more tests.
The possible lighting software tests that can be performed are:
¾ Color interface and its behavior in various lighting design software programs.
¾ Absorptance of materials and their properties depending upon their usage like
glazing, furniture, wall, fenestrations etc.
¾ Point by point illuminance/ luminance value testing and the accuracy of light
readings on various surfaces and at various locations on the model.
¾ Distinguishing the ambient light and its distribution on various surfaces.
¾ Outdoor/indoor daylighting calculations and the accuracy of the sensors to
record the light values simultaneously when placed under two different
comparison tests.
¾ Latitude, Longitude or Altitude, Azimuth inputs and their effects on the light
calculations during the simulations in the lighting software programs.
¾ Accuracy in analysis & simulations of complex building profiles, drawings.
¾ Levels of performance in importing complex building shapes and number of
surfaces for simulation and analysis.

222

¾ Possible features available and the lighting software capabilities in identifying
the surrounding environmental and climatic changes. Accuracy in the values
of the Uniform/cloudy sky and their levels.
¾ Availability and the accurateness of the simulations with the input of the
weather data. The lighting software capabilities in anticipating and analyzing
the shade and shadows patterns. Available features in the lighting software
programs for the rainy day analysis and the simulations.
¾ Quality of the rendered image (Photo realistic), the capabilities to import the
photometric files for simulation, levels of walkthroughs, video animations, the
capability of lighting software program to import large file formats and the
possible export extensions of output files to various other software programs.
¾ The capability of the software program to be used on various operating
systems and their compatibility to run on different computer platforms.
¾ The levels of ease of use of various lighting software programs and the
possible available levels of analysis. The levels of help provided by the
tutorials, their access and availability for the users including technical support
¾ Check for the availability of all the latest lighting design concepts in
architectural construction like the fenestrations (Light shelves, sky lights, etc),
glare analysis and daylight factor distributions.

223
• Identifying the bug locations and fixing them.
Possible future work can be to identify the location of the bugs in these software
programs and trying to fix them. It can also be that a proper justification can be provided
for the reasons for the test findings that occurred in my test. Some of the possible test
fixings that can be taken over are:
¾ The transmissive properties of materials in AGI32 for the glazing assigned
and the transmissive properties of materials. This will greatly help in
designing glass buildings and running the simulations on them using this
lighting software program.
¾ Fixing the specularity fudge factor in 3D studio max and
transmissive/reflectance simulations outputs in the color coded plot windows
as explained in the test conclusions.
¾ Fixing up the specularity property in the Lightscape lighting software
program.
¾ Trying to resolve the problems of lamp aiming and the error window dialog
box to be more interactive in Desktop Radiance. Most of the problems that I
have encountered while testing have been included in the test report, which
can be fixed.

• Retesting the old tests to reconfirm the appropriateness of the test.
The other possibility of future work can be to retest all the tests that I have
performed using the same conditions and bringing out new findings that
contradict my statements about the tests.

224
There are two possibilities where one can either use the same parameters chosen
by me and run the tests with the same conditions which can bring out if any of my
test have wrong findings and errors in them or the second possibility is to run the
test with similar material properties and similar conditions and bring out the
findings that may support my tests or contradict. Either of these is always
welcome as we are intended to state the truth and express the facts and hence
everyone has the right to contradict false statements and expressions. Human
errors are always possible, no matter how professional we are in any field.

• Using the help of the external evaluator to check for and compare the results
of his findings. Etc.
The other series of possible future work can be to ask the help of
professionals and their guidance in re-performing the tests to bring out the right
method that has to be followed while running the specific tests. All my tests use a
very general approach of testing and analysis which is basically intended to mimic
the amateur users who know very little or medium level users of these lighting
design software programs. Taking the advice of the expert in each program or the
manufacturers and their research team can help us in knowing the right approach
and procedure which is a great asset for the readers of this thesis who can go
through the document and know what not to do. A the new thesis can help them
guide in which way to do it. This thesis is more of problem searching and hence a
new thesis can be the problem resolving approach or a problem avoiding
approach.

225

BIBLIOGRAPHY

1. AGI32 html help, ver-1.80.
2. Amarpreet, S. Conclusions on the lighting software program (Ecotect). “A study of
daylighting techniques and their energy implications using designer friendly
simulation software”(2003: 5). http://www.sbse.org/awards/docs/2003/Sehti.pdf.
(Downloaded 06Aug2006).
3. Bryan.H et al,. Comments on Daylighting Setup program (Lightscape).
“Lighting/Daylighting Analysis: A Comparision”.
http://www.sbse.org/awards/docs/Autif.pdf, 2006. (Downloaded 06Aug2006).
4. Christakou, Dimitrios Evangelos, Amorim, Claudia Naves David, “Daylighting
Simulation: Comparison of Softwares for Architect’s Utilization”. (Downloaded
06Aug2006)
5. CIBSE Lighting Guide LG6 (1992).
6. Derek Phillips, The Lit environment, Architectural Press, 2002
7. Glare analysis report on Walt Disney concert hall, Marc E.Schiler.
8. Harvey Bryan, Sayyed Mohammed Autif, “Lighting/Daylighting Analysis: A
Comparision” School of Architecture, Arizona State Univeristy, Tempe, AZ.
85287-1605. (Downloaded 06Aug2006).
9. Marc.E.Schiler, Simplified Design of Building Lighting, John Wiley and sons, 1992
10. http://www.chemie.fu-berlin.de/cgi-bin/units?from=&to=&have=lux&want=nit.
(Downloaded 06Aug2006).
11. http://www.eere.energy.gov/buildings/tools_directory/subjects.cfm/pagename=subj
ects/pagename_menu=materials_components/pagename_submenu=lighting_system
(Downloaded 06Aug2006)
12. http://www.schorsch.com/kbase/glossary/luminance.html. (Downloaded
06Aug2006).
13. http://www.sciencemadesimple.com/metric_conversion_chart.html. (Downloaded
06Aug2006).
14. http://lesowww.epfl.ch/anglais/Leso_a_frame_sof.html. (Downloaded 06Aug2006).

226
15. http://hyperphysics.phy-astr.gsu.edu/Hbase/vision/photomcon.html#c1.
(Downloaded 06Aug2006).
16. Illuminating Engineering Society, IES Lighting handbook, IES, Newyork, 1972
17. K.Shanker Rao et al., Intermediate Physics. S.Chand, 1996.
18. Koenigsberger, Manual of Tropical Housing and Building, Orient Longman, 1998
19. Light Guide, Light Loss Factor,
http://www.lightsearch.com/resources/lightguides/lightloss.html, 2006.
(Downloaded 06Aug2006).
20. Lightscape, “Lightscape Visualization System, version 3 for Windows NT and
Windows 95)”. Ligthscape Tutorial.
21. R.J.Hitchcock, “Advancing Lighting and Daylighting Simulation: The transition
from analysis to design aid tools” May 1995.
http://www.btech.lbl.gov/papers/37285.pdf. (Downloaded 06Aug2006).
22. Ross, Foundations of 3D studio max-6,
23. Ultimate lighting design, teNeues, 2005
24. Wikipedia, http://en.wikipedia.org/wiki/Image. (Downloaded 06Aug2006).
25. William M.C.Lam, Perception and lighting as formgivers for architecture, Mc.
Graw Hill Book Company, 1966.

227
APPENDIX A: PHYSICAL UNITS
1

APPROXIMATE CONVERSIONS FROM
STANDARD / US CUSTOMARY UNITS TO SI / METRIC UNITS
(Scroll down for conversions from metric to standard measurements)
SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL
LENGTH
in inches 25.4 millimeters mm
ft feet 0.305 meters m
yd yards 0.914 meters m
mi miles 1.61 kilometers km
AREA
in
2
square inches 645.2 square millimeters mm
2
ft
2
square feet 0.093 square meters m
2
yd
2
square yard 0.836 square meters m
2
ac acres 0.405 hectares ha
mi
2
square miles 2.59 square kilometers km
2
VOLUME
fl oz fluid ounces 29.57 milliliters mL
gal gallons 3.785 liters L
ft
3
cubic feet 0.028 cubic meters m
3
yd
3
cubic yards 0.765 cubic meters m
3
MASS
oz ounces 28.35 grams g
lb pounds 0.454 kilograms kg
TEMPERATURE
o
F Fahrenheit (F-32) x 5 / 9
or
(F-32) / 1.8
Celsius
o
C
ILLUMINATION
fc foot-candles 10.76 lux lx
fl foot-Lamberts 3.426 candela/m
2
cd/m
2
FORCE and PRESSURE or STRESS
lbf poundforce 4.45 newtons N
lbf/in
2
poundforce per square inch 6.89 kilopascals kPa

1
http://www.sciencemadesimple.com/metric_conversion_chart.html

228
APPROXIMATE CONVERSIONS FROM
SI / METRIC UNITS TO STANDARD / US CUSTOMARY UNITS
2
SYMBOL
WHEN YOU
KNOW
MULTIPLY
BY
TO FIND SYMBOL
LENGTH
mm millimeters 0.039 inches in
m meters 3.28 feet ft
m meters 1.09 yards yd
km kilometers 0.621 miles mi
AREA
mm
2
millimeters 0.0016 square inches in
2
m
2
square meters 10.764 square feet ft
2
m
2
square meters 1.195 square yards yd
2
ha hectares 2.47 acres ac
km
2
square kilometers 0.386 square miles mi
2
VOLUME
mL milliliters 0.034 fluid ounces fl oz
L liters 0.264 gallons gal
m
3
cubic meters 35.314 cubic feet ft
3
m
3
cubic meters 1.307 cubic yards yd
3
MASS
g grams 0.035 ounces oz
kg kilograms 2.202 pounds lb
TEMPERATURE
o
C Celsius 1.8C + 32 Fahrenheit
o
F
ILLUMINATION
lx lux 0.0929 foot-candles fc
cd/m
2
candela/m
2
0.2919 foot-Lamberts fl
FORCE and PRESSURE or STRESS
N newtons 0.225 poundforce lbf
kPa kilopascals 0.145 poundforce per square
inch
lbf/in
2

2
http://www.sciencemadesimple.com/metric_conversion_chart.html

229

APPENDIX B: CONVERSION OF UNITS

CONVERSIONS
3
:

NITS TO LUX
= conformability
1.000000e+00 m.-cd
1.000000e+00 m.-cd-radian2

LUX TO NITS

conformability
1.000000e+00 m.-cd-radian2
1.000000e+00 m.-cd

LIST OF SOME OF THE AVAILABLE DAYLIGHTING SOFTWARE PROGRAMS
4
. (Numbers
marked * are free for downloads).

3
http://www.chemie.fu-berlin.de/cgi-bin/units?from=&to=&have=lux&want=nit

4
http://www.eere.energy.gov/buildings/tools_directory/subjects.cfm
TOOL WEBSITE APPLICATION
1. ADELINE
http://www.ibp.fhg.de/wt/ade
line/
Daylighting, lighting, commercial buildings
2. AGI32 http://www.agi32.com Daylighting, lighting, rendering, roadway.
3. Bsim2002 http://www.bsim.dk
Daylighting, building simulation, thermal analysis,
indoor climate, energy
4.*
Building
design
advisor
http://gaia.lbl.gov/BDA
Daylighting, energy performance, design,
prototypes, case studies, commercial buildings.
5.* Daylight http://www.archiphysics.com Daylighting, daylight factor
6.* DAYSIM http://www.daysim.com
Annual daylight simulations, electric lighting
energy use, lighting control
7. Ecasys
http:http://www.fundamental
energy.com
Energy program management
8. Eco Lumen http://www.ecolumen.com Lighting design, energy efficient
9.* EcoAdvisor http://www.ecoadvisor.com
Lighting, HVAC, online interactive & multimedia
training, sustainable commercial buildings
10. ECOTECT
http://www.squ1.com

Natural and artificial lighting, Envr.design and
analysis, conceptual design, validation, solar
control, overshadowing, etc.
11.
Energy
Profile
Tool
http://www.energyprofiletool
.com
Benchmarking, energy efficiency screening, end-use
energy analysis, building performance analysis,
utility programs.
12.*
ENVSTD
and LTGSTD
http://www.energycodes.gov

Federal commercial building standard, code
compliance, energy savings
13. FLUCS http://www.ies4d.com Daylighting, Illumination.
14.* HiLight http://www.eley.com Lighting, energy code, code compliance.
15. LESODIAL
http://lesowww.epfl.ch/anglai
s/Leso_a_frame_sof.html
Daylighting, early design stage, user-friendliness.
16.
Lighting
Boy
http://www.LightingBoy.com
Lighting retrofit, audit, lighting design, existing
buildings.
17.
Load
Express
http://www.trane.com/comm
ercial/software
Light commercial buildings, design, heating and
cooling loads, HVAC.
18.* Radiance
http://radsite.lbl.gov/radiance
/HOME.html
Daylighting, lighting, rendering.
19.*
Radiance
control
Panel
http://www.squ1.com Daylighting, lighting, radiance, ray tracing, glare
20.
Radiance
Interface
http://www.ies4d.com Daylighting, lighting, glare, ray tracing.
21.* SkyVision
http://irc.nrc-
cnrc.gc.ca/ie/light/skyvision/
Daylighting, light well, fenestration, skylight,
optical characteristics.
22.
Sombrero
3.01
http://nesa1.uni-siegen.de/
Solar shading, solar radiation, building, geometry,
solar systems.
23.* SuperLite
http://eetd.lbl.gov/btd/tools/s
uperlite/superlite2.html
Daylighting, lighting, residential and commercial
buildings.
24.*
The
Lightswitch
Wizard
http://irc.nrc-
cnrc.gc.ca/ie/light
Annual daylight simulations, electric lighting
energy use, lighting controls.
25.* Visual
http://www.VisualLightingSo
ftware.com
Lighting, lighting design, roadway lighting, visual,
lumen method.
26. Lightscape Daylighting, lighting, ray tracing, glare.
27.
3D Studio
Max 8.0
Daylighting, lighting, rendering.

230
APPENDIX C: LIGHTING SOFTWARE CUTSHEETS

ADELINE

SOFTWARE NAME: ADELINE
COMPANY:
ADDRESS:

231
COST:
PROJECT PARTNERS:
1.

Fraunhofer-Institut für Bauphysik
Abteilung Wärmetechnik
Nobelstraße 12
70569 Stuttgart
2.

Bundesministerium für Wirtschaft
und Technologie
Villemombler Straße 76
53123 Bonn
3.
Projektträger Biologie, Energie,Umwelt
des Bundesministeriums für Wirtschaft und
Technologie
Postfach 1913
52425 Jülich

232
4.
tional Laboratory
ng 90 - Room 3111
Lawrence Berkeley Na
Buildi
CA 94720 Berkeley
USA
5.
édérale École Polytechnique F
de Lausanne
CH-1015 Lausanne
6.

d
Spectroscopy
Sölvegatan 14
S-22362 Lund
University of Lun
Dept. of Atomic

7.

DESCRIPTION:
ADELINE is an integrated lighting design computer tool developed by an international
about behaviour
research team within the framework of the International Energy Agency (IEA) Solar
Heating and Cooling Programme Task 12.
ADELINE provides architects and engineers with accurate information
and the performance of indoor lighting systems. Both natural and electrical lighting
problems can be solved, in simple rooms or the most complex spaces.

233
g a
(including: geometric, photometric, climatic, optic and human response) to
ODELLER as CAD interface, the (day-)lighting tools
ADELINE Version 3 is now available. It runs on PCs under Windows 95/NT. (The
version 2.0 for PCs under DOS is still available).
ADELINE produces innovative and reliable lighting design results by processin
variety of data
perform light simulations and to produce comprehensive numeric and graphic
information.
ADELINE contains SCRIBE-M
SUPERLITE and RADIANCE and the link to energy simulation tools using
SUPERLINK or RADLINK.

234
urate information about the behaviour and the performance of indoor
rtificial lighting problems can be solved in simple rooms or the most
sponse) to
imulations and to produce comprehensive numeric and graphic
be divided into the successive
phases that are described in the following sections.

ADELINE is an integrated lighting design computer tool that provides architects and
engineers with acc
lighting systems.
Both natural and a
complex spaces.
ADELINE produces innovative and reliable lighting design results by processing a
variety of data (including: geometric, photometric, climatic, optic and human re
perform light s
information.
The process of day- and artificial lighting design can
AGI

SOFTWARE NAME: AGI32
COMPANY: Lighting Analysts, Inc.
ADDRESS: 10440 Bradford Rd, Unit A
Littleton, Colorado 80127 USA
tel. (303) 972-8852 fax. (303) 972-8851
email: info@agi32.com
COST:
Itemi zed List
Product Description Quantity
Unit
Price
Qty.
Discount
Extended Price
AGI32 with SupportPlus 1 $1295 $525 $770
AGI32 LAN License 1 $4300 $0 $4300
AGI32 WAN License 1 $6400 $0 $6400
Photometric Toolbox32
Professional Edition
1 $299 $100 $199
Photometric Toolbox32 LAN
License
1 $1095 $0 $1095
Photometric Toolbox32 WAN
License
1 $1595 $0 $1595
AGI32 Introductory Training
Course
1 $795 $0 $795
Total
Amount
$15154

235

236
PRODUCT DESCRIPTION:
AGI32 Lighting Software-Version 1.8
This lighting calculation and visualization program provides compelling new features like
multiple page custom report creation with Page Builder, interactive Walk capability in
Render mode, enhanced textures, luminaire symbols and library objects as well as
raytrace image output within Daylight Studies.
AGI32 version 1.8 also makes predicting lighting performance easier with the following
new features: SnapTo command is cognizant of Room and Object endpoints, file
management dialogs such as Open and Save have been upgraded with Windows XP style
interface, customizable AGI32 job file Templates to predefine consistent items for typical
layouts, and a customizable File System method that allows more robust file sharing.
In addition, Buildings have been deprecated. Building shapes have been converted to
Objects allowing for more flexibility with the Object modification commands. These
features, as well as many more user driven wish list items continue to make using AGI32
intuitive and adaptable.
New features geared towards those requiring a technical edge include definable Zenith
Luminance for calibration of IES and CIE sky models to local conditions and Tone
Mapping in ray traced images allowing for more natural looking reproductions of tones in
high dynamic range renderings.
http://www.agi32.com/index.htm
HARDWARE REQUIREMENTS:

237
http://www.agi32.com/Products/AGI32/agi32.htm
Minimum Recommended
Pentium III based PC Pentium IV, Athlon, or Better
256 Mb RAM 512 Mb RAM
NT4 (requires SP6), 2000, XP 2000 or XP
CD-ROM or DVD CD-ROM or DVD
OpenGL support provided by Windows Video card w/32 Mb memory or more
and OpenGL acceleration
Minimum resolution
1024 x 768
16 bit color support
Any Windows compatible printer Color printer, large format color inkjet
plotter
Sound
Optional: Large format digitizer
VRML Standalone or plug-in for IE or
Netscape

BSIM2002

SOFTWARE NAME: BSIM2002
COMPANY: Danish Building and Urban
Research
ADDRESS: P.O.Box 115
Hoersholm DK-2970
Denmark
Telephone: +45 (45) 86 5533
Facsimile: +45 (42) 86 7535
E-mail: bsim-support@dbur.dk
Website: http://www.bsim.dk
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Package of easy-to-use and flexible programs for evaluating the indoor climate
and energy conditions as well as the designing of the heating, cooling and ventilation
plants. The BSim2002 package comprise the programs: SimView (user interface and
graphic model editor), tsbi5 (simultaneous thermal and moisture building simulation
tool), XSun (dynamic solar and shadow simulation), SimLight (daylight calculation tool),
Bv98 (compliance checker), SimDXF (CAD import facility) and SimPV (building
integrated PV-system calculation).

238
BSim2002 permits calculation on complex buildings with several (in principle
indefinitely many) thermal zones and rooms simultaneously. BSim2002 utilises data from
all structures in the thermal and moisture evaluation. BSim2002 interact directly with
other applications for compliance with building regulations, dynamic - with animated
results - solar and shadow distribution, CAD import for model making and daylight
calculations. Results from BSim2002 can be exported as boundary conditions for CFD
programs. Building models can be exported as input files to Radiance for detailed light
analyses.
Keywords
building simulation, energy, daylight, thermal analysis, indoor climate
Validation/Testing
N/A
Expertise Required
Users must have some general knowledge on building design and how buildings behave
thermally in order create the building model. Courses are offered.
Users
Approximately 125 licences, of which most are in Denmark.
Audience
Engineers, researchers and students.
Input
When using BSim2002 the building is
divided into rooms, some in thermal zones.

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Only rooms in thermal zones will be simulated dynamically, the rest can be used in other
applications. The following groups of information are needed: materials, building
component, equipment and systems.
Rooms and thermal zones
The geometry of the rooms are created in the model graphic editor or imported from
CAD drawings. Room or rooms are attached to thermal zones by drag and drop in the
tree structure of the model.

Constructions and materials
Description of type, density, thermal capacity and thermal conductivity. Walls, floors and
roof constructions are built in layers according to the description of the materials. All
materials and constructions are defined in a database and attached to the model as
defaults in one operation or one by one by drag and drop from the database.

Systems and functions
Internal loads (e.g. persons, lighting, equipment, moisture load), natural ventilation (e.g.
infiltration, venting), heating (floor/construction and/or radiator) and cooling radiators,
and ventilation systems. All such "systems" are defined by the physical component as
well as how it is controlled and when in function.

Ventilation plants
Supply and exhaust fans as well as total pressure rise and total efficiency. Units of heat
recovery, heating and cooling coils, and humidifiers.

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Together with the control strategy chosen, these data form the base for calculating the
power demand and energy consumption necessary for running the ventilation plants.

Automatic control strategies
Are defined for each individual ventilation plant, e.g. changes in temperature, volume
flow, moisture content, readjustment between winter and summer periods. Differentiation
is made between data of the physical components of the plant (in the company catalogue)
and the control function (automatic or manual equipment).

Climate data
BSim2002 uses climate data in binary format, but has a built-in function for converting
text formatted hourly data to the binary format. This function can automatically convert
climate data files in EnergyPlus/ESP-r weather format.

Default libraries
BSim2002 comes with standard libraries for: constructions (walls, floors, roofs, and
internal walls), materials, glass, window frames, people loads, schedules and national
constants. The connection between the model and the libraries is handled by drag and
drop operations in the building model. The user can choose from these libraries or define
new input.

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Input interface
Input is given as properties of the individual objects or directly in the graphical
representation of the model.

Output
The user can chose any of the calculated parameters for each construction layer, each
thermal zone plus data from ambient climate, as output on hourly, weekly, monthly or
periodical basis, in either tabular or graphic form. The variables can also be presented in
"sum" graphs or tables. Finally the energy balances for each zone or the whole building
can be shown. Outputs can be copied (graphics or numbers) for presentation in other
programs.

Computer Platform
PC equipped with an Intel Pentium II processor (min. 200 MHz) or compatible.
Operating system MS-Windows 98/NT/2000/XP.

Programming Language
Visual C++

Strengths
Analysis of the indoor thermal and moisture climate in complex buildings or buildings
with special requirements for the indoor climate. Simultaneous simulation of energy and
moisture transfer in building constructions. Intuitive graphic user interface.

Weaknesses
Simple models for airflow, i.e. no zone model taking into account the airflow caused by
wind pressure on the facades. A more detailed airflow-model are being developed and
implemented (2003 - 2004).

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SOFTWARE NAME: BUILDING DESIGN ADVISOR (BDA)
DEVELOPED BY: Building Technologies Department of the Environmental
Energy Technologies
Division
At Ernest Orlando Lawrence Berkeley
National Laboratory.
FUNDED BY: In part, by the California Institute for Energy Efficiency (CIEE),
Assistant Secretary for Energy Efficiency
and Renewable Energy,
Office of Building Technology, State and
Community Programs,
Office of Buildings Systems of the U.S. Department of Energy.
ADDRESS: 1 Cyclotron Road, Mail Stop 90-3111,
Berkeley, CA 94720,
phone: (510) 486-7799
fax: (510) 486-4089
e-mail: JJLoffeld@lbl.gov

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Product description:
The BDA is a computer program that supports the concurrent, integrated use of
multiple simulation tools and databases, through a single, object-based representation of
building components and systems. Based on a comprehensive design theory, the BDA
acts as a data manager and process controller, allowing building designers to benefit from
the capabilities of multiple analysis and visualization tools throughout the building design
process. The BDA has a simple Graphical User Interface that is based on two main
elements, the Building Browser and the Decision Desktop.
The BDA is linked to a Schematic Graphic Editor that allows
designers to quickly and easily specify basic building
geometric parameters. Through a Default Value Selector, the
BDA automatically assigns "smart" default values to all non-
geometric parameters required by the analysis tools from a
Prototypes Database. These default values can be easily
reviewed and changed through the Building Browser. In this
way BDA supports the use of sophisticated tools from the
initial, schematic phases of building design.
The BDA is implemented as a Windows™-based application for personal computers. In
addition to the Schematic Graphic Editor, the current version of the BDA is linked to
DCM (daylighting computation module), ECM (Electric lighting computation module)
and DOE-2 (energy analysis module). The current version also provides the choice of
using either the English or the Metric unit system.

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Future versions of BDA will be linked to additional analysis and visualization tools, such
as Radiance (day/lighting and rendering) and ATHENA (lifecycle cost of materials).
Plans for the future also include links to cost estimating modules, building rating systems,
CAD software and electronic product catalogs.
(http://gaia.lbl.gov/bda/bdainfo.htm)
SYSTEM REQUIREMENTS:

Minimum / Recommended:
• Pentium 75 / 200 or better.
• Windows 95, 98, NT 4.0, 2000.
• 16 / 32MB RAM under Windows 95 or 24 / 64MB RAM under Windows NT 4.0.
• 50 / 70MB or larger hard disk space.
• 640x480 / 1024x768 or higher screen resolution.
DAYSIM
SOFTWARE NAME: DAYSIM
ADDRESS: Institute for Research
in Construction (IRC)
National Research
Council Canada (NRC)
1200 Montreal Road, Bldg. M-24,

http://irc.nrc-cnrc.gc.ca/ie/lighting/daylight/daysim_e.html
Room 320
Ottawa, ON, Canada, K1A 0R6
Telephone: (613) 993-9703
Fax: (613) 954-3733

Project partners:
• DAYSIM's dynamic daylight simulation module to simulate annual
illuminance profiles was developed and implemented by Christoph Reinhart at
the Fraunhofer Institute for Solar Energy Systems (Aug 1998 to Jan 2001).
• The DAYSIM subprogram to model the short-time step dynamics on indoor
illuminances was developed and implemented by Oliver Walkenhorst at the
Fraunhofer Institute for Solar Energy Systems (Oct 1999 - Apr 2001).
• The manual lighting control model Lightswitch and the stochastic user
occupancy model were developed by Christoph Reinhart at the National
Research Council Canada (Feb 2001 - August 2003).

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• DAYSIM's graphical user interface was programmed in JAVA at the National
Research Council Canada by the Prashant Jois (Jan 2003 - Apr 2003) and
Melissa Morrison (May 2003 - Aug 2003).
• A modified version of the RADIANCE program rtrace that calculates a set of
daylight coefficients using either the traditional RADIANCE approach or
Roland Schregle PhotonMap forward raytracer was programmed by
Augustinus Topor at the Fraunhofer Institute for Solar Energy Systems (Mar
2003 to July 2003).
• Recommended illuminance levels and maximum lighting power densities
have been added to the documentation by Annegret Fitz (Oct 2003 to Mar
2004).

Product description:
DAYSIM is a daylighting analysis software that calculates the annual daylight
availability in arbitrary buildings as well as the lighting energy use of automated lighting
controls (occupancy sensors, photocells) compared to standard on/off switches. The
program combines the backward raytracing software Radiance, developed by Greg Ward
at the Lawrence Berkeley National Laboratory, with a daylight coefficients approach.
The underlying sky model to calculate annual illuminance profiles is the Perez all
weather sky model. A stochastic model from Skartveit and Olseth has been adapted to
calculate the short-time-step development (down to 1 minute) of indoor illuminances
based on hourly mean direct and diffuse irradiance values.
Annual Illuminance Profiles are coupled with user occupancy data to predict the annual
use of electric lighting in a building zone depending on the lighting and blind control
strategy. The underlying manual lighting control model LIGHTSWITCH is based on
monitored occupancy behavior in several field studies.
Who may use it?
Anybody, who is interested in evaluating the annual daylight availability in a building
either during the initial design phase or later. The method is especially suitable for people
who already have experience in simulating with RADIANCE as DAYSIM requires the
same input files and simulation parameters as RADIANCE.
Getting started
The fastest way to start using DAYSIM is to download the installation files for Windows
2000 or Linux/Unix and work through the DAYSIM tutorial. Should you have any
problems installing the software or using it, please contact Christoph Reinhart . So far,
the binaries have been tested under:
Windows 2000
Windows XP
SUSE Linux 6.4
CRAY/SGI Origin 2000/108
RedHat 7.2
Debian 3.0

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Free RADIANCE-based daylighting analysis software to predict the annual daylight
availability and electric lighting use in arbitrary buildings for manual and automated
lighting and blind controls.

Keywords
annual daylight simulations, electric lighting energy use, lighting controls
Validation/Testing
DAYSIM is based on LBNL’s validated RADIANCE software. A validation study of
DAYSIM has been published under: Reinhart C F, Walkenhorst O, “Dynamic
RADIANCE-based daylight simulations for a full-scale test office with outer venetian
blinds.” Energy & Buildings, 33:7 pp. 683-697, 2001.
Expertise Required
DAYSIM is ideal for individuals who have experience using RADIANCE as it uses the
same input files. For those who currently lack this expertise, the Lightswitch Wizard is a
lighter online version of DAYSIM that allows to analyze sidelit peripheral offices.

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Users
Between Mar 2002 and Nov 2003 over 330 individuals from more than 120 A & E firms
and 95 research institutions downloaded the DAYSIM
software.
Audience
Building designers to design buildings with “enough but
not too much” annual daylight; lighting designers to assess
the energy/cost benefits of lighting and window blinds
controls.
Input
RADIANCE building scene files, a RADIANCE sensor point grid file, and EnergyPlus
weather data.
Output
• annual illuminance/luminance profile due to daylight at investigated sensor points
• daylight autonomy distribution
• daylight factor distribution
• annual electric lighting energy use for different
lighting control systems
Computer Platform
Windows 95, 98, 2000, and XP as well as Linux/Unix
operating systems.

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Programming Language
JAVA, C

Strengths: DAYSIM is the first program that provides reliable predictions of lighting
energy use in offices by considering occupant control of lighting and blinds. The
underlying user behavior model is based on field study data. The tool should be used to
estimate the energy saving potential of automated compared to manual lighting controls.
Annual daylight availability predictions are very accurate since they are based on
RADIANCE simulations. The program comes with a tutorial and detailed online help
functions.
Weaknesses
Since DAYSIM is based on RADIANCE, it requires the same amount of knowledge of
how to properly set the RADIANCE simulation parameters.

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ECOTECT

SOFTWARE NAME: ECOTECT
COMPANY: Square one.
ADDRESS:
COST:
PROJECT PARTNERS:

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254

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FLUCS
SOFTWARE NAME: FLUCS
COMPANY: IES Limited
ADDRESS: 141 St James Road
Glasgow, Scotland G4 0LT
United Kingdom
Telephone:+44 (141) 226 3662
Facsimile:+44 (141) 226 3747
E-mail:drdon@ies4d.com
Website:http://www.ies4d.com
COST:
Project partners:
Product description:
Design mode calculates, using the UK CIBSE design method, the optimum
number and spacing of identical luminaires in a rectangular array to provide the required
illumination levels on the working surface and to meet the maximum glare requirement.
Analysis mode calculates the actual illumination levels due to any number of luminaires
of any type, taking into account the reflections from walls, ceiling, floor and partitions.
Illumination levels due to daylight through windows can also be calculated separately or
combined with the artificial lighting. It includes a large database of manufacturers'
luminaires and lamps. This database is editable and data may be imported/exported in
CIBSE or IES (North America) format.

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Keywords
illumination, daylighting

Validation/Testing
N/A

Expertise Required
Lighting and electrical design.

Users
Many throughout the UK and Europe.

Audience
Electrical building services engineers and lighting designers.

Input
Design mode requires room dimensions, working surface height, surface reflectances,
minimum illumination level, and maximum glare. Analysis mode requires room
dimensions, working surface height, window and partition locations, surface reflectances,
and illumination plane.

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Output
Single-page plots of room layout or illumination levels (in plan or pseudo-3d). Single-
page printouts of input data or illumination levels. Output file with selected input data
and results.

Computer Platform
PC running Windows 95/98 or NT (3.51 or higher). 100 MB RAM, 100 MB disk space,
CD-ROM drive.

Programming Language
Visual Basic, Fortran 77

Strengths
Large database, CIBSE design method.

Weaknesses
Not ideal for non-rectangular rooms and sloping ceiling.

DAYLIGHT
SOFTWARE NAME: DAYLIGHT

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COMPANY: ArchiPhysics
ADDRESS: United States
E-mail: troy@archiphysics.com
Website: http://www.archiphysics.com
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
An easy to use daylighting program. Daylight program calculates the daylight factor
distribution in a room at the workplane. User interface is similar to a CAD program
allowing user to resize and move windows with mouse. Window and wall properties can
be changed and average DF and
UxA values are automatically
calculated. It should not take more
than one minute to become
proficient in using the Daylight
program.
Keywords
daylighting, daylight factor
Validation/Testing
None.

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Expertise Required
None.
Users
Web download, new tool.
Audience
Educators, students and anyone else that wants to understand how windows relate to
daylight.
Input
Program starts with a wall and a window. The user may have up to three windows in the
wall. Windows are resized and repositioned by using a mouse.
Output
Graphical output of daylight distribution at workplane.
Computer Platform
Windows and Mac OS/X
Programming Language
Real Basic
Strengths
Easy to use.
Weaknesses
Only calculates values for a uniform sky. Still in beta stage.

ECASYS
SOFTWARE NAME: ECASYS
COMPANY: Fundamental Objects Inc
ADDRESS: 800 Robert Dean Drive
Downingtown, Pennsylvania
19335
United States
http://www.fundamentalenergy.com/
Telephone: +1 (610) 873-8022
Facsimile:+1 (610) 873-8772
E-mail: bills@fo.com
Website: http:http://www.fundamentalenergy.com
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Large scale, low income, program management, web application.
ecasys is best suited for use within an energy agency to gather disparate applications and
processes together; or, for use in a Utility, to monitor the energy programs that they fund.
Using a standard Internet Explorer browser, you can access the backend, fully relational
SQL database from anywhere with an Internet connection.
Modules within ecasys include contractors, customers, invoices, funders, programs,
service, measure and auditing, with full online HTML reporting. Online HTML help is
provided as a standalone module, that is also directly linked into the application's screens.

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Keywords
energy program management
Validation/Testing
Tested with regression testing and completely retested (every field, every screen) with the
current release.
Expertise Required
Data entry through energy program management.
Users
About 300 users in the US.
Audience
Energy Program Managers
Input
HTML (web-based) data input.
Output
HTML (web-based) screens display outputs. An optional online adhoc report writer is
now available as well, which allows you to create your own reports, without requiring
programming.
Computer Platform
Internet
Programming Language
N/A
Strengths
N/A

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Weaknesses
N/A
Availability
The cost of ecasys varies, depending upon the number of users, number of programs
managed and the number of servers that you wish to run it on. Fundamental Objects (FO)
optionally provides hosting for the application and database, so that you can concentrate
on managing, rather than maintaining the web software.
ECO LUMEN
SOFTWARE NAME: ECO LUMEN
COMPANY: Eco Lumen
ADDRESS: Plot #4 & 5,
Noida Export Processing Zone
Noida, UP 201305
India
Telephone: +91(120) 4562356
Ext 630
Facsimile: +91 (120) 4567635
E-mail:
ecolumen.info@tatainfotech.com
Website:
http://www.ecolumen.com
COST: INR 12,500/-.

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PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Lighting design software, structured to
recommend lighting designs that
optimize the electricity bills while
ensuring appropriate illumination
levels in the facility as per ISI standards. The software is built around a user-friendly

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interface and requires elementary inputs such as room dimensions and usage parameters.
The software can then recommend the most appropriate lighting equipment for the
facility as well as the optimum number of fittings required. For existing facilities, Eco
Lumen recommends the most appropriate upgrade options, for replacing the existing
lighting products with more energy efficient ones. Eco Lumen also offers the option of
re-using any applicable fittings for the room being designed, thus reducing the renovation
cost for the facility.
Keywords
lighting design, energy efficient
Validation/Testing
Eco Lumen has been validated against results from some of the leading lighting design
software.
Expertise Required
No training is required for using Eco Lumen. The accompanying Help & User Manual
provide any run-time assistance that may be needed by the user.
Users
More than 3000 users are estimated to be using the software internationally.
Audience
Targeted at Facility Managers for any organisation, useful for architects, lighting
designers and energy auditors.
Input
The user needs to provide elementary information such as room dimensions and color,
and usage pattern (purpose for which room is used, amount of time for which room is
used, applicable energy tariff etc). Eco Lumen provides data such ISI standard
recommended Illumination levels based on the purpose for which the room is used. Eco
Lumen also allows users to select the desired lighting products for the facility from the
database available with the software.
Output

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r

Eco Lumen provides customizable
reports, allowing the user to select any o
all of the input parameters as well as the
lighting design details, energy
consumption details and financial
implications (such as pay back analysis
and life cycle costing) as the report parameters. Eco Lumen also provides comparison
reports in case of renovation or upgrade designs. Further, pre-formatted print reports are
also available to the user.
Computer Platform
Eco Lumen runs on any Windows 9x or higher platform
Programming Language
Visual Basic 6.0, with MS Access as the database
Strengths
Eco Lumen can reduce the lighting electricity bills for any facility by as much as 30%.
Eco Lumen is therefore of great benefit to any facility designers looking to reduce their
electricity bills. The simplicity with which the lighting designs can be scientifically
created by Eco Lumen also makes the software ideal for architects, interior designers and

266
lighting designers looking to save time and effort spent on lighting designs. Further,
Energy Auditors and Energy Consultants find the software extremely useful for auditing
existing facilities for lighting related energy efficiencies.
Weaknesses
The current version of Eco Lumen is not designed for outdoor lighting and day light
calculations.
Availability
The list price of Eco Lumen is INR 12,500/-. A trial edition of the software can be
downloaded from the website. The software can then be registered by sending payment
through Demand Draft / Cheque in the name of Tata Infotech Limited, payable at
Mumbai, India.
ECO ADVISOR
SOFTWARE NAME: ECO ADVISOR
COMPANY: The Deringer Group
http://www.ecoadvisor.com/html/ecoDaylighting.htm#
ADDRESS: 1349 Addison Street
Berkeley, California 94702
United States
Telephone: (510) 843-9000
Facsimile: (510) 843-9005
E-mail: eco@deringergroup.com
Website: http://www.ecoadvisor.com
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Interactive, online multimedia training and decision support tool for
sustainable commercial buildings. EcoAdvisor is highly graphically oriented and highly
interactive. When fully developed, it will engage the user via numerous animations and
interactions such as mouse-overs, 'more info' drill-down options, radio button choices,
sliders, drag-and-drop exercises, fill-in-the-blank exercises, and goal-oriented, problem-
solving exercises. The current beta version contains several examples of graphic
animations and user-interactions. Interactive multimedia is highly cost-effective
compared with instructor-led learning for users can learn 40% faster than in classroom
situations, and each user can learn at his/her own pace. Quizzes will be available for all

267
course content, for at least one quiz question has been developed for virtually every page.
The user can take a quiz at any time to gauge his/her mastery of the content for a
particular lesson topic before, during or after reviewing the content.

EcoAdvisor is currently in beta version with content being added routinely as are
refinements to user-interaction and navigation capabilities. The first 2 training modules
being developed for EcoAdvisor are HVAC energy fundamentals and O&M and lighting
quality and energy efficiency (see also Energy Trainer for Energy Managers – HVAC
Module for a description of the source of the HVAC content). The beta version contains
example content from a number of HVAC lessons, plus two example HVAC lesson
topics. The next version (expected April 30, 1999) will include improved navigation
features, additional HVAC example content, plus introductory example lighting content.
Keywords
online interactive training, online multimedia
training, sustainable commercial buildings, lighting,
HVAC
Validation/Testing
N/A
Expertise Required
Basic knowledge of use of the internet.

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Users
In beta version.
Audience
Owners, managers, and other decision-makers for commercial buildings. Other key
audiences include developers / construction
agencies, design professionals, contractors,
commissioning agents, O&M personnel, and
students.
Input
No required inputs.
Output
The lesson 'content' is the output. Some of the pages can be quite rich in layered 'drill-
down' information and/or radio button options that can be explored at length.
Computer Platform
Any web browser, level 4 or later, screen resolution of 1024x768 or greater.

269

270

Programming Language
Macromedia Dreamweaver Attain, Javascript, MS Access 97, SQL, FormZ, Photoshop 5,
Director 6, Fireworks.

Strengths
Best used for self-paced, self-directed entry-level learning. Also best used by decision-
makers to quickly address key energy-related issues during building design and retrofit
(this use being developed now). It is also useful as a study aide when taking the HVAC
and lighting portions of the various Federal courses on Energy Training for Energy
Managers (FEMP, Army, Navy, Air Force).
Weaknesses
Online navigation features need refinement and clarification; this will occur in the second
beta version. Also, more complete content is needed, which is being added continuously.
Requires level 4+ browsers and screen resolution of 1024x768 or more. Known bug:
when using Internet Explorer 4, a bug prevents use of the inch-pound / metric units
toggle; this toggle works fine in Netscape 4.
Availability
Currently there is no charge for the viewing the example content material now available
for viewing on the website. In the future, costs will be listed for accessing the content of
major lessons. Available on the Internet at http://www.ecoadvisor.com

SOFTWARE NAME: ENERGY PROFILE TOOL
COMPANY: EnerSys Analytics Inc.
ADDRESS: 2989 Delahaye Drive
Coquitlam, British Columbia V3B 6Y9
Canada
Telephone:+ 1 (604) 552-0700
Facsimile:+44 (141) 226 3747
E-mail: info@enersys.ca
Website: http://www.energyprofiletool.com
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:

A customizable, commercially available energy analysis tool. Users enter
information about their facilities to receive detailed profiles of the energy use, as well as
benchmark comparison results. The tool helps identify opportunities to reduce energy and
costs, and take the next steps to long-term savings.

271

272
Keywords
benchmarking, energy efficiency screening, end-use energy analysis, building
performance analysis, utility programs
Validation/Testing
The analysis approach for determining end-use energy requirements closely agrees with
actual DOE-2 simulations, as has been confirmed and documented in internal and
professional papers. Background models and benchmark data reference hundreds of
calibrated site models and detailed load research data. System provides for calibration
against billing data, ensuring that modelled energy use correlates with actual billing data.
Expertise Required
No expertise needed, but the more knowledgeable the users are about their building
characteristics and concepts, the better the results.
Users
Various web sites have been accessed thousands of times by users in the U.S. and
Canada.
Audience
Building facility managers and owners, utilities, engineers, designers, policy analysts.
Input
User supplies information about building type, weather region, floor area and general
HVAC system. Existing buildings should also provide billing data for benchmarking to
be most relevant. However, specifying general shell, HVAC, lighting and equipment, and
DHW information provide for a more accurate analysis. All entries provide for defaults
which are estimated to be the most typical or average for the building characteristic.

273
Data entry is accommodated on two levels: 1) Basic - provides automated controls (e.g.,
pulldown lists, radio buttons) and limits data entry to the most relavent and important
building characteristics, 2) Advanced - supplements the Basic level by allowing for
additional entries and discrete entry for all inputs.
Output
Typically, users receive energy benchmark and end-use breakdown information about
their facility in the form of graphs and tables. They receive low-cost/no-cost energy
saving tips, and a list of energy efficiency measures show good potential of save energy
in their facility. The tool also generates a PDF report that shows results and action plan in
printable format. The system may be customized to provide further information, such as
comparisons between facilities and more detailed energy analysis results.
Computer Platform
Web-based
Programming Language
C, ASP, PERL
Strengths
Provides a quick, initial estimate on building energy performance and benchmarking,
including relative greenhouse gas emission levels. The tool helps identify opportunities to
reduce energy and costs, which is intended to act as early decision-making tool to
empower the user to take the next steps to securing energy savings.

274
Weaknesses
Intended for entry-level analysis and is not detailed enough to assess very specific energy
management scenarios. Therefore, it cannot replace having a professional personally
assess specific opportunities for a given facility.
Availability
Available for limited, free trial use at www.energyprofiletool.com. To purchase a
customized application, contact EnerSys for a customized cost proposal.
HILIGHT
SOFTWARE NAME: HILIGHT

275
COMPANY: Eley Associates
ADDRESS: 142 Minna Street
San Francisco,
California, California 94105
United States
Telephone: (415)
957-1977 Facsimile: +1 (509) 372-4484
E-mail: info@eley.com
Website: http://www.eley.com
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Lighting code compliance program for the Hawaii Model Energy Code, ASHRAE
Standard 90.1-1989, and the Federal building energy standard 10 CFR 435. HiLight is
designed to aid lighting designers in determining and documenting compliance with the
code's lighting requirements. The program covers all of the code's lighting requirements,
including interior lighting power, interior controls, and exterior lighting power. HiLight is
easily adapted to work with energy codes in states with lighting requirements similar to
ASHRAE 90.1-1989.

276

Keywords
lighting, energy code, code compliance
Validation/Testing
N/A
Expertise Required
Basic knowledge of Windows software (3.1 or higher) and lighting systems.
Users
More than 100, total number of downloads from web site unknown.
Audience
Lighting designers, electrical engineers, building code officials, energy consultants.
Input
The HiLight interface consists of seven folders. The user may move between folders
when entering information. Results may be viewed immediately.
Project. Enter general project information.
Fixtures. Create a list of lighting fixture types used in the project and enter input power.
Import and export lists to work with other applications. Or import from an extensive
library that includes default input power. Also can import fixture lists from other HiLight
project files.
Controls. List the types of controls used in the design (e.g. occupancy sensor, dimming
switch). May import and export lists of controls.
Spaces. Create a list of spaces with information about dimensions, occupancy type,
fixtures, and controls. May import and export lists of spaces.

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Exterior. List the exterior areas to be illuminated and choose the fixtures to be installed.
Miscellaneous. Review the checklist of other lighting requirements.
Results. Find out if the design complies. View summaries of spaces to discover problem
areas.
Output
HiLight creates compliance reports that may be viewed on screen, printed, or saved as a
text file. The report summarizes compliance results, such as total W/ft2 of interior and
exterior lighting, as well as space-by-space results. The reports also list tables of input
information.
Computer Platform
486 or better PC with Windows 3.1/95/98/NT, 1 MB of hard drive space, and 8 MB of
RAM.
Programming Language
Visual Basic
Strengths
HiLight fits well into the lighting design process by allowing importing and exporting of
data. Information developed in other applications such as spreadsheets does not have to
be reentered for energy code compliance calculations. HiLight calculates compliance
with the complex control requirements in the Hawaii Model Energy Code and ASHRAE
Standard 90.1. It also calculates lighting power control credits and area factor based on
the user's input.
Weaknesses
HiLight is not a lighting design program and does not perform illuminance calculations.

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Availability
Technical contact in Hawaii:

Howard Wiig
Energy, Resources and Technology Division
Department of Business, Economic Development and Tourism
State of Hawaii
P.O. Box 2359
Honolulu, HI 96804
(808) 587-3811
email: hwiig@hawaii.dbedt.gov

HiLight may be downloaded for free from the following sites:http://www.eley.com
http://www.hawaii.gov/dbedt/ert/mec/app-b.html

LESODIAL
SOFTWARE NAME: LESODIAL
COMPANY: Solar Energy and
Building Physics Laboratory
ADDRESS: Swiss Federal
Institute of Technology
LESO/EPFL
Lausanne CH-1015
Switzerland

279
Telephone: + 41 (21) 693 55 54
Facsimile: + 41 (21) 693 27 22
E-mail: Bernard.Paule@epfl.ch
Website:
http://lesowww.epfl.ch/anglais/Leso_a_frame_sof.html

COST: Prices in Swiss Francs (CHF) : 550.-
for education purposes : 350.- 1 licence, 550.- site licence
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Gives architects relevant information regarding the use of daylight, at the very first stage
of the design process. This software allows users to:
• Calculate daylight factor values on the work plane.

280
• Estimate daylighting autonomy (according to the lighting requirements, Leso-
DIAL estimates the time during which artificial lighting could be switched off
(mid-Europe climate).
• Optimise the daylighting performance. Based on the use of fuzzy logic rules, the
diagnosis facility of Leso-DIAL indicates out the possible weak points of your
design.
• Allows the user to compare his design with pre-simulated and/or existing real
rooms stored in a database.
Up to 30 openings can be described (6 for each facade and the roof).
Keywords
Daylighting, early design stage, user-friendliness
Validation/Testing
N/A
Expertise Required
The use of this tool does not require any learning time and no specific knowledge is
needed. A Lexicon is accessible from any stage of the design. About 100 terms of the
lighting vocabulary are presented in a richly illustrated way.
Users
Architects & engineers offices, Universities (International)
Audience
Architects, engineers, students in architecture and building sciences

281
Input
Description of both photometry and geometry is based on the handling of graphic and
linguistic items (precise numerical values may also be used).
Output
Daylighting performance (CIE overcast sky), daylight factor values on the workplane
(isolines and tables), daylighting autonomy on the workplane (isolines and tables), and
recommendations (linguistic diagnosis).
Computer Platform
PC-compatible, 386 or higher, Windows 3.1 or higher.
Computer : PC 486 or more
Memory : RAM : 16Mb, Disk space : 10 Mb:
System : Windows 3.11, Windows'95, Windows NT
Programming Language
Asymetrix ToolBook
Strengths
Very easy description and use, fast calculation. Particularily well adapted to testing
various configurations in the early design stages. English, French and German versions.
Weaknesses
Simplified calculation method (split-flux) dedicated for shoebox shape. Only one climate
(mid-Europe) for the first version.
Availability
Site-license software packages for CHF 550.- purchased through LESO-EPFL at the above address. Check the
WWW pages for additional information. 50% discount for education.
LIGHTING BOY
SOFTWARE NAME: LIGHTING BOY
COMPANY: Lighting Boy Software
Development
ADDRESS: 14763-46 Avenue
Edmonton, Alberta
T6H 5M6
Canada
Telephone: +1 (780) 940-3428
Facsimile: +1 (780) 436-2245
E-mail: lightboy@v-wave.com
Website: http://www.LightingBoy.com
COST: $550.00
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Designed for people in the Performance Contracting business, lighting
specialists, engineers and project managers. The program was designed based on the
author's field experiences in performance contracting. This experience led to the
realization that no existing software provided for the definition of the databases,
calculations, and reports required to reach a sufficiently high level of efficiency and cost
control required for successful performance contracting.

282

283
The database can take as input specific information concerning existing fixture
specifications and using these specifications the following operations can be carried out:
For each existing fixture appropriate modifications are detailed with reference to fixture
type, lamp type and ballast type, using a master specification table that the user can
modify as required for the project. Detailed analysis of power consumption in kW, kVA
and kWh before and after the retrofit. Cost summaries are based upon fixture, lamp and
ballast costs with labor broken down on a per fixture price. A per room break down of
installation instructions are provided specifying to the contractor existing conditions, the
type of retrofit to be performed, the amount and type of material needed. Accurate pricing
from the contractor is possible because the contractor is provided with a description of
existing conditions and precise installation instructions.
Keywords
lighting retrofit, audit, lighting design, existing buildings
Validation/Testing
N/A
Expertise Required
Practical experience in lighting audits and familiarity with various types of lighting
fixtures, ballasts and lamps. A good understanding of Windows.
Users
Numerous utlities and performacne contractors.
Audience
Utilities, engineers, architects, lighting designers, performance contractors

284
Input
Specific information and specifications on lamps, ballasts and fixtures in the context of
project, buildings, floors and rooms or task areas.
Output
Detailed analysis of power consumption in kW, kVA and kW.h before and after the
retrofit Cost summaries are based upon fixture, lamp and ballast costs with labour broken
down on a per fixture price. By the use of local power rate tables entered by the user
together with pre-retrofit site billing, estimated pay back periods are calculated. A per
room break down of installation instructions are provided specifying to the contractor
existing conditions, the type of retrofit to be performed, the amount and type of material
needed. Accurate pricing from the contractor is possible because the contractor is
provided with a description of existing conditions and precise installation instructions.
Computer Platform
Windows 95, 98 or NT with Service Pack 3 or higher, additional features are available if
you have Office 97 or 2000 loaded.
Programming Language
Visual Basic
Strengths
You make Lighting Boy as detailed as you need and is very fast. Over 30 reports from
energy use, materials to contractors instructions right down to a per room basis. Custom
reports and pre-built database(s) available.

285
Weaknesses
It takes a bit of time to build your first template.
Availability
The system sells for $1000.00 Canadian Dollars or approximately $550.00 US Funds
depending on the dollar. The first 90 days all reports are customized for each client and
any possible changes in forms and reports layout and design are free. All updates for the
first 90 days are also free, updates are provided on CD-ROM or email.

LOAD EXPRESS
SOFTWARE NAME: LOAD EXPRESS
COMPANY: Trane Company
ADDRESS: 3600 Pammel Creek Road
Building 17-1
La Crosse , Wisconsin 54601-
7599
United States
Telephone: (608) 787-3926
Facsimile: (608) 787-3005
E-mail: CDSHelp@trane.com
Website: http://www.trane.com/commercial/software
$295
RODU DESC
lid
r can
ulations for small to medium-sized light

COST:
PROJECT PARTNERS:
P CT RIPTION:
Calculates detailed HVAC load reports for heating, cooling and airflow
capacities. Based on ASHRAE algorithms, you are assured of accurate results and va
designs. The intuitive Windows graphical interface makes Load Express a powerful
engineering tool with a very short learning curve. The "rookie" or experienced use
quickly and accurately perform load calc
commercial buildings with confidence.

286

287
eate air
e your data entry time. Explore different design options using the "Alternative"
rcial buildings, heating and cooling loads, HVAC
ation/Testing
nowledge of HVAC equipment, systems, and terms.
tely 750 users worldwide.
ical systems designers who size and calculate loads for HVAC systems.
design parameters and system configurations.
chrometric state points, and peak load summaries at building, air handler,
r zone level.
Create project files with Load Express in just 4 easy steps. Select a weather
profile, enter simulation parameters, define the zones/rooms in the building and cr
handler descriptions. Expandable, built-in libraries of building design parameters
streamlin
feature.
Keywords
Design, light comme
Valid
N/A
Expertise Required
Basic k
Users
Approxima
Audience
Mechan
Input
Building
Output
Print any of the 15 summary reports such as design cooling/heating loads (design
capacities), psy
o

288
um recommended), Windows 3.1 or higher, 16 MB
k space.
g Language
c
lets you control
tail to enter and makes editing any specification painless.
d calculations for small commercial jobs, it is limited to
0 system inputs.

y
at your office if you prefer. Contact the
.D.S. Support Center for more information.

Computer Platform
PC-compatible, 486 or higher (Penti
RAM, 10 MB free hard dis
Programmin
Visual Basi
Strengths
The intuitive interface and simplified input methods, with the reliability of ASHRAE
calculations, make this program both usable and accurate. Load Express
the level of de
Weaknesses
With the program's focus on loa
20 zone and 2
Availability
The cost for Load Express is $295 for a standard single license and $442.50 for a
site/LAN license. Call the Support Center to receive special pricing for educational
purposes or current promotional discounts. A yearly renewal fee of 23% of the purchase
price entitles the customer to unlimited free phone support, as well as automatic updates
and documentation. All Trane C.D.S. software programs have an unconditional 30-da
money-back guarantee. "Patches" are also available for download from our web site,
listed above. We offer on-site training at our headquarters in La Crosse, WI, as well as
regional training at sites throughout the U.S. or
C

289
RADIANCE
SOFTWARE NAME:
COMPANY
ADDRESS:
486-4089
ail:
http://radsite.lbl.gov/radiance/HOME.html
COST Free
PROJECT PARTNERS
ODUCT DESC

ilar quantities related to the visual environment.
RADIANCE
: Lawrence Berkeley National Laboratory
Mail Stop 90-3111
1 Cyclotron Road
Berkeley, California 94720
United States
Telephone: (510) 486-7916
Facsimile: (510)
E-m
CKEhrlich@lbl.gov
Website:
:
:
PR RIPTION:
Advanced lighting simulation and
rendering package; calculates spectral radiance values
(illuminance & color) and spectral irradiance (illuminance & color) for interior and
exterior spaces considering electric lighting, daylight and interreflection. Used by
architects and designers to predict illumination, visual quality and appearance of design
spaces. Used by researchers to evaluate new lighting and daylighting technologies and
study visual comfort and sim

290
ng, daylighting, rendering
ise Required
of computer literacy required; 4 days training, minimum.
ce
l translators have been written by third parties for
rchiCAD and others. A third-party (shareware) CAD program, Vision3D, can prepare
input directly.
and contours, visual comfort levels,
,
egabytes of free disk space,
Keywords
lighti
Validation/Testing
N/A
Expert
High level
Users
Over 200.
Audien
Daylighting, lighting, and architectural designers.
Input
Geometry and materials of design space, including luminaire photometry and surface
reflectance characteristics. Translators are available for DXF, Architrion, and IESNA
standard luminaire files. Additiona
A
Radiance

Output
Luminance and illuminance values, plots
photograph-quality images and video animations.
Computer Platform
UNIX-compatible workstation, e.g. Sun, Silicon Graphics, Hewlett Packard, DECstation
NeXT, Mac II running A/UX; 8- or 25-bit color display, 20 m

291
8 megabytes of RAM, and math coprocessor recommended. IBM 386-compatible DOS

rogramming Language
(Kernnigan and Ritchie standard)
trengths
hysical accuracy in a graphics rendering package, reliability and source code
vailability; arbitrary surface geometry and reflectance properties.
port has been produced but is not currently being distributed.
P
C
S
P
a

292
Weaknesses
acks a graphical user interface, comprehensive documentation, and examples; too few
AD formats supported.
vailability
ersion 2.4 (1994) available free of charge from technical contact via posted tape
artridge (media exchange).

L
C
A
V
c

293
RADIANCE CONTROL PANEL

293
RADIANCE CONTROL PANEL
COST: Free
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
A front-end to the Radiance Synthetic Imaging System developed at
Lawrence Berkeley Laboratories. It is an excellent public domain command-line tool for
radiosity-based lighting simulation.
SOFTWARE NAME: RADIANCE CONTROL PANEL
COMPANY: C/O Centre for Research in the Built Environment
ADDRESS: Cardiff University
Bute Building,
King Edward VIII
Ave
Cardiff, Wales
CF10 3NB
United Kingdom
Telephone: +44
(29) 2087 5977
Facsimile: +44 (29) 2087 4623
E-mail: sales@squ1.com
Website: http://www.squ1.com

294
The role of The Radiance e of the more mundane
tasks when using Radiance, once a model has been created.
Keywords
radiance, lighting, daylig
Validation/Testing
N/A
Expertise Required
Compared to what you need to run Radiance...
4 days training, minim e required.
Users
Output
Saves .RIF files as well as DOS Batch (.BAT) files to control the Radiance run.
Computer Platform
indows 95, 98, NT, 2000 & XP

Control Panel is simply to automate som
hting, ray tracing, glare
um" ... very little expertis
"High level of computer literacy required;
Over 200 users worldwide
Audience
Architects, lighting engineers & building designers.
Input
Reads Radiance Instruction Files (.RIF) and Radiance Model Data(.RAD) files.
W
Programming Language
C++

295
rate Radiance images. Can
very little knowledge of Radiance.
age. Desktop Radiance must already be installed.
ability
WARE > Radiance Control Panel in the main menu of
Strengths
Automates some of the more mundane tasks required to gene
be used with
Weaknesses
No help file at this st
Avail
Free, go to FREE STUFF > FREE
the Square One web site to download.

296
RADIANCE INTERFACE
COMPANY
141 St James Road
0LT
Facsimile: +44 (141) 226 3747
E-mail: drdon@ies4d.com
Website: http://www.ies4d.com
COST:
product description:
Provides an interface to Radiance which can accurately simulate the visible radiation in a
space. Radiance is a powerful lighting simulation program that synthesises images from
the 3D geometric model of the building. Radiance/4D+ is available for both daylight and
electrical lighting simulation and provides photo-realistic images of the illuminated
model. The simulation results can be displayed as photo-realistic images; lux values at
user selected positions in the simulation 'frame', lux and daylight factors contours; glare
factors and comfort indices.
Keywords
Lighting, daylighting, ray tracing, glare
SOFTWARE NAME: RADIANCE INTERFACE
: IES Limited
ADDRESS:
Glasgow, Scotland G4
United Kingdom
Telephone: 44 (141) 226 3662

297
Validation/Testing
N/A
Expertise R
High end 3D modelling
with Model Builder(Mo
Users
Mnay in UK and Europe.
Photo-realistic im
Contact IES at the above address or visit the IES4D web site.
equired
tool. Familiarity
delIT).
Input
3D geometry, material properties, viewing
and simulation parameters.
Output
ages, lux levels, daylight
factors, glare analysis.
Computer Platform
Unix; Windows NT
Programming Language
C
Strengths
Easy-to-use interface,
Weaknesses
N/A
Availability

SOFTWARE NAME: SKY VISION
NY: National Research
ncil Canada
SS: Institute for
ruction
1200 Montreal
ttawa, Ontario
K1A 0R6
Canada
hone: +1 (613) 990-6868
Facsimile: +1 (613) 954-3733
E-mail: aziz.laouadi@nrc-cnrc.gc.ca
ebsite: http://irc.nrc-cnrc.gc.ca/ie/light/skyvision/
:
TNERS:
COMPA
Cou
ADDRE
Research in
Const
Road, M-24
O
Telep

W

COST
PROJECT PAR

298

PRODUCT DESCRIPTION:

299
alculates the overall optical characteristics (transmittance, absorptance, reflectance and
olar Heat Gain Coefficient) of conventional and tubular skylights, performance
es (well
availability
ctor and
illuminance) and
daily/annual
lighting energy
savings. SkyVision
accounts for the
skylight shape and
glazing, geometry of the indoor space (curb, well, room), skylight layouts, lighting and
nique--it uses
s to compute the optical
kylight, light well, fenestration, glazing, optical characteristics, daylighting.

C
S
indicators of skylight/room interfac efficiency and coefficient of utilization),
indoor daylight
(daylight fa
shading controls, site location and sky/ground conditions. SkyVision is u
the state-of-art glazing models and ray-tracing-based method
characteristics of skylights and indoor daylight availability.
Keywords
S
Validation/Testing
N/A

300
xpertise Required
und in daylighting is required.
b manufacturers, building designers, architects, engineers, fenestration
research
on skylight shape, size and glazing type, dimensions and surface
the indoor space (curb, light well, room), lighting and shading controls, site
condition.
aracteristics (transmittance, absoptance, reflectance and SHGC) of the
of the light well and coefficient of utilization, daylight factor under a
.
l Basic
E
Basic engineering backgro
Users
More than 150 users since its release in March 2003.
Audience
Skylight and cur
councils, and
Input
Users provide data
reflectance of
location, and sky
Output
Overall optical ch
skylight, efficiency
given sky condition, total illuminance from sky and sun beam lights on indoor surfaces,
floor surface area coverage, and daily and annual lighting energy savings.
Computer Platform
PC-compatible running Windows
and education institutions.
NT/2000/XP
Programming Language
Fortran 90 and Visua

Strengths

301
skylights of different shapes
zing types. Standard and weather-based sky conditions can be simulated. Easy to
sers can compare skylight products
ergy performance based on built-in criteria. Export results to Excel and
s buildings with rectangular shapes. Thermal energy (heating/cooling) calculation
ownloaded free of charge from the web site.
Accurate, detailed calculation of optical characteristics of
and gla
learn and get quick results on skylight performance. U
and their en
energy simulation software.
Weaknesses
Handle
is not implemented yet. Detailed user manual not currently available (quick start
instructions are provided, and on-line help is available).
Availability
Can be d

302
SOMBRERO 3.01
COMPANY
+49 (271) 740-3817
US$
PRODUCT DESCRIPTION:
A PC-tool to calculate
shadows on arbitrarily oriented
surfaces. In designing both active use of solar energy (domestic hot water, photovoltaic)
as well as passive solar architecture, shading and lighting of planes plays an important
role. SOMBRERO provides quantitative results for shading of collectors or windows by
buildings, overhangs, trees or the horizon. These results can be used either directly for
visualization or as input for other thermal simulation programs.
Keywords
Solar shading, solar radiation, building geometry, solar systems
SOFTWARE NAME: SOMBRERO 3.01
: Group for Building Physics & Solar Energy / Fachge
ADDRESS: University of Siegen / Universität - Gesamthochsch
Siegen D-57068
Germany
Telephone:
Facsimile: +49 (271) 740-3820
E-mail: heidt@physik.uni-siegen.de
Website: http://nesa1.uni-siegen.de/
COST: 200
PROJECT PARTNERS:

303
Validation/Testing
N/A

Expertise Required
Basic knowledge about geometry and solar radiation
Users
The users of SOMBRERO are distributed all around the world. The program is not
restricted to a special country or region.

304
tects, engineers for thermal simulation of buildings or solar plants
Input
Three-dimensional objects are built up by their boundary planes. Up to 200 plane areas
with 12 points each can be treated. Objects like houses and trees are predefined and
described by parameters like height, width and position in space. Single planes are
described by their vertex-points in the two-dimensional co-ordinate system related to the
plane itself (in case of rectangles simply by their length and heigth) and positioned by
indication of azimuth, elevation and origin in the three-dimensional space.
tion can be selected freely. Foliage of trees and reflection factors of
ns of the given input data, SOMBRERO creates a VRML (Virtaul Reality
Output
Output of SOMBRERO are values of the geometrical shading coefficient. The user can
choose whether SOMBRERO calculates only the daily course of the shading coefficients
as mean values for a month, or whether hourly data for every day of a month have to be
calculated.
Computer Platform
The minimal system requirements for the work w
better), about 5 MB of free space on the hard disc, Windows 95 / NT, graphics board with
resolution 800 x 600.
Audience
Archi
Time steps for simula
the ground can be given as monthly schedules.
By mea
Modeling Language) file, which shows the shading situation in a three-dimensional
model.
ith SOMBRERO are: PC (468 DX or

Programming Language
Delphi
Strengths
Easy to handle.
Weaknesses
Unknown
Availability
A free demo-version of SOMBRERO can be downloaded from the web site of the Group
for Building Physics & Solar Energy at the University of Siegen with the address
http://nesa1.uni-siegen.de/. This demo-version is fully operational for 10 days after its
first installation. For unlimited use of the program one needs to purchase a license for 200
€ (= 200 US$).

305

306
SUPERLITE
SOFTWARE NAME: SUPERLITE
COMPANY: Lawrence Berkeley National Laboratory
ADDRESS: 901 D St., SW, Suite 950
Washington, DC 20024
United States
hone: (202) 646-7959
Facsimile: (202) 646-7800
E-mail: RJHitchcock@lbl.gov
Website: http://eetd.lbl.gov/btd/tools/superlite/superlite2.html

ARTNERS:
RIPTION:
rnally
ting, residential and commercial buildings
alidation/Testing
N/A
Expertise Required
Average level of computer literacy; understanding of basic lighting concepts.
Telep

COST:
PROJECT P
PRODUCT DESC
Daylighting and electric analysis; calculates interior illuminance levels in
complex building spaces. Analysis accounts for direct, externally reflected and inte
reflected light. Used for residential and commercial applications.
Keywords
daylighting, ligh
V

307
Users
Approximately 500 worldwide.
Audience
Architects, lighting designers eers.
Input
Space geometry, surface reflectance, aperture transmittances, lum
ile.
PC-com can be compiled on other platforms.
Programming Language
FORTRAN
n-interactive input/output.

, researchers, engin
inaire description; input
file prepared using standard text or word processor.
Output
Interior point-by-point illuminance levels; preformatted text f
Computer Platform
patible, with math co-processor;
Strengths
Complex geometry allowed; variety of sky conditions; illuminance levels on user-
oriented planes; daylighting and electric lighting; accurate flux exchange inter-reflection
calculation.
Weaknesses
Only diffuse surfaces; no
Availability
Download from web site

308
lighting analysis program designed to accurately predict interior illuminance
lighting systems. SUPERLITE
a user to model interior daylight levels for any sun and sky condition in spaces
ctric lighting levels in addition to
hting prediction. This allows lighting performance simulation for integrated
be modeled
m calculates lighting levels on all interior surfaces, as well as on
tions of
LITE 2.0 is intended to be used by researchers and lighting
o require detailed analysis of the illuminance distribution in architecturally
aces. SUPERLITE continues to be enhanced to address current program
ey capabilities of SUPERLITE 2.0 include:
trically complex spaces can be modeled, such as L-shaped rooms,
ternal obstructions
w glazing can be clear glass, diffusing glass or clear glass with a diffusing
• daylight calculations can be performed for a variety of sky conditions, for a given
sun position or geographic location, or for user-defined irradiance data

About SUPERLITE 2.0
A powerful
in complex building spaces due to daylight and electric
enables
having windows, skylights or other standard fenestration systems. The principle new
feature of Version 2.0 is the capability to calculate ele
the daylig
lighting systems. Daylighting and electric lighting systems can also
separately. The progra
planes that can be arbitrarily positioned to represent work surfaces or other loca
interest to the user. SUPER
designers, wh
complex sp
limitations.
Key Capabilities
Some of the k
• geome
trapezoidal surfaces, interior partitions and ex
• windo
sheer curtain

309
• illuminance data are calculated for points on user specified planes
ture data are flexibly entered as candlepower distribution files
s
x spaces
ut
structions, and gives details of program input, output and operation
by-step tutorial is presented to take users through the entire process of
ral example input files are
des b ence
tables a
disc s
listed at the end of the manual.

• electric lighting fix
Key Limitations
Some of the key limitations of SUPERLITE 2.0 include:
• all surface reflection of light is assumed to be perfectly diffuse
• complex fenestration systems such as venetian blinds and specular light shelve
cannot be modeled
• input and output are accomplished only through ASCII text files
• the numbers of surfaces, windows and nodes can be restrictive for comple
SUPERLITE 2.0 operates on IBM-PC compatible computers under the DOS operating
system. A minimum of 600 kilobytes of RAM and a math coprocessor are required.
Program input files can be created by using any standard word processor. Program outp
is written to text files that can be viewed or printed by the word processor. This manual
gives a general overview description of the SUPERLITE 2.0 program, provides
installation in
procedures. A step-
performing and evaluating a SUPERLITE simulation. Seve
cri ed to give insight into simulation methods. Appendices listing useful refer
nd a glossary of lighting analysis terms are also provided. For more detailed
us ions of the simulation algorithms employed by SUPERLITE, refer to the sources

310

THE LIGHTSWITCH WIZARD
SOFTWARE NAME: The Lightswitch Wizard
COMPANY: National Research Council Canada
ADDRESS: Institute for Research in Construction
1200 Montreal Road, M24
Ottawa, Ontario K2P 0Z4
Canada
Telephone: +1 (613) 993-9703
Facsimile: +1 (603) 954-3733
E-mail: Christoph.Reinhart@nrc-cnrc.ga.ca
Website: http://irc.nrc-cnrc.gc.ca/ie/light
COST:
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Web-based, non-expert analysis
tool to support daylighting-related design
decisions in peripheral private offices
during an early design stage
(www.buildwiz.com).

311
he Lightswitch Wizard offers a comparative, reliable, and fast analysis of the amount of
aylight available in p hting energy performance
ng ocells) compared to standard
on/off switches. Blinds are either manually or automatically controlled.
Keywords
annual daylight simulations, electric lighting energy use, lighting controls
Validation/Testing
The Lightswitch Wizard is based on the validated, RADIANCE-based dynamic daylight
simulation method DAYSIM. Relevant journal articles are listed in the technical
background section.
Expertise Required
Intuitive web interface that does not
require any special training. Simulation
instructions and a glossary are provided
online.
Users
Over 500 users in the first month since
launch.
Audience
building designers, lighting designers

T
d eripheral private offices as well as the lig
of automated lighti controls (occupancy sensors, phot

312
ne
atted
dict annual electric lighting energy use, falsecolor maps of the

or higher) and
hs
itch provides reliable predictions
ing occupant control of lighting
The underlying user behavior model is based on field study data. The tool
aving potential of automated compared to manual
ghting controls. Annual daylight availability predictions are very accurate since they are
ased on pre-calculated RADIANCE simulations.
Input
Building site and orientation, office dimensions, surface properties, lighting and blinds
control systems, and occupant properties are specified through pull-down menus. Onli
help is provided throughout.
Output
Side-by-side daylighting analysis of two private perimeter offices. Preform
simulation reports pre
daylight factor and daylight autonomy distribution, and detailed information on user input
and underlying simulation assumptions.
Computer Platform
Internet Explorer (5.5
Netscape (7.0 or higher).
Programming Language
Java and C
Strengt
Lightsw
of lighting energy use in private offices
consider
and blinds.
should be used to estimate the energy s
li
b

313
esses
pplication that can be used at no charge from www.buildwiz.com. User
glossary and technical background information are available for download.
Weakn
The number of supported building geometries and types is limited.
Availability
The Lightswitch Wizard is an online a
manuals, a

314
VISUAL
SOFTWARE NAME: VISUAL
Conyers, Georgia 30012
United States
Telephone: +1 (800) 279-8043
E-mail: support@VisualLightingSoftware.com
Website: http://www.VisualLightingSoftware.com
COST: $100
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Comprehensive
lighting analysis software
engineered for demanding interior
and exterior applications. Visual
lighting design software integrates
an advanced 3-D modeling
environment with an intuitive interface—providing a unique and powerful extension of
the design process. Professional presentation capabilities enable you to quickly develop,
analyze, and modify advanced lighting designs.
COMPANY: Acuity Brands Lighting
ADDRESS: One Lithonia Way

315
Visual performs direct and interreflected component calculations and provides the ability
to quickly compose professional presentations.
Keywords
e
The algorithms used by Visual lighting design software to calculate illuminance levels in
diffuse architectural m ommonly accepted techniques in the illumination
use a guided step-by-step format and
-specific lighting knowledge. The Professional Edition
lighting design knowledge is beneficial.
sales representatives.
lighting, lighting design, roadway lighting, visual, lum n method
Validation/Testing
odels follow c
engineering field, and are based on luminous radiative transfer theory, which has been
proven to be a special case of finite element analysis.
Expertise Required
The Basic Edition and Roadway Lighting Tool
require only application
incorporates a 3-D graphical interface for the construction and analysis of complex
lighting models. Prior CAD experience and
Users
More than 5000.
Audience
Architects, electrical and civil
engineers, lighting designers, design-
build contractors, electrical
contractors and designers, retrofit
companies, and lighting equipment

316
areas using graphical and keyboard data
ques. Use imported photometry files (IES, EULUMDAT, or CIBSE TM-14)
ts.
ghting metrics.
ths
l interface and th
nd most versatile lighting design software packages to use.
ions or rendering.
$100 per single user license. The Roadway Lighting Tool is $50 per
Input
Define lighting model parameters and calculable
entry techni
files to configure and place luminaires.
Output
Architectural designs with quantified results depicting directional illuminance,
luminance, or exitance values. Designs can be printed or exported in DWG/DXF forma
The Roadway Lighting Tool reports
roadway luminance, veiling
luminance and STV li
Computer Platform
Windows 95/98/ME/NT/2000/XP
Programming Language
Visual Basic
Streng
Intuitive graphica e ability to model complex architecture provide one of
the easiest a
Weaknesses
Does not perform daylighting calculat
Availability
Basic Edition is free. Professional Edition is
single user license.

317
LIGHTSCAPE
SOFTWARE NAME: IGHTSCAPE
COMPANY: Lightscape Technologies
ADDRESS:
COST: $495
PROJECT PARTNERS:
PRODUCT DESCRIPTION:
Lightscape
integrates radiosity and ray-
Radiosity accurately calculates the intens
allowing subtle lighting effects (e.g., soft
shadows and color bleeding between surfaces).
Lighting information is precalculated and stored
as an integrated part of model surfaces. Once
the radiosity solution has been determined, the
user can move interactively through the fully
rendered 3-D environment.
Users can generate and interactively explore 3-D models. High-quality animation
frames can be generated at real-time rates. Users can also get true global illumination
effects (indirect diffuse lighting, soft shadows, color bleeding, etc.)
L
tracing technologies with a physics-based lighting interface.
ity of light throughout a 3-D environment,

318

318
Lightscape works with 3-D mode utoCAD and 3D Studio.
Users can import existing 3-D geometry (e.g., DXF and 3DS on NT platforms, and DXF
and OBJ on SGI platforms). There are Performer, Softimage, Wavefront and Inventor
translators. The radiosity solution can be exported to VRML and Open Inventor. Form-Z
includes a direct exporter to the Li
A Mesh-to-Texture tool converts a scen
representing the surfaces and light intensity,
surfaces) into texture maps, resulting
a reduced polygon count. This enables develope
but high visual richness.
Lightscape's library series includes hundreds of
objects, materials, etc. that can be dragged and dropped
into scenes.

System requirements: For PCs: Lightscape recomm
a Pentium with 64 MB RAM, running Windows 95 or W
Price: Lightscape 3.1.1 costs $495.
PLATFORM: Windows 95/98/NT and silicon grpahic

ling applications such as A
ghtscape preparation file (.lp).
e's radiosity solution (i.e., the polygon mesh
color, shading and shadows related to those
in a model with a photorealistic appearance, despite
rs to maintain low geometric complexity
ends
indows NT 3.5 or 4.0.

Abstract (if available)

Abstract This thesis outlines an approach to compare the various most commonly used daylighting/ lighting design software programs available in the market and evaluate their performances based upon their capabilities to fulfill the assigned tasks by the users/lighting designers. The most widely available and commonly used potentially powerful lighting software programs for quantitative and qualitative daylight performance will be evaluated by assigning some test on various lighting concepts. A summary chart and the detailed evaluation procedures performed is to be created to guide the users and emphasize the available features and accuracy of the software for Architectural daylighting. These tests will bring to light the hidden bugs within these lighting software programs and will help users, cautioning them of the possible data errors while performing the analysis of their project jobs using these lighting design software programs. Physical models or base case real buildings may be used depending upon the requirements and time to analyze the accuracy of the final outputs of the computer software program generated models.

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Asset Metadata

Creator Namburi, Venkata Sri Kaliki Varma (author)

Core Title Comparative evaluation of lighting design software programs for daylighting in buildings

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 11/15/2006

Defense Date 11/01/2006

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag lighting software programs analysis,OAI-PMH Harvest

Language English

Advisor Schiler, Marc E. (committee chair), Noble, Douglas (committee member), Srinivas, Ch. (committee member)

Creator Email namburi@usc.edu

Permanent Link (DOI) https://doi.org/10.25549/usctheses-m139

Unique identifier UC1307279

Identifier etd-Namburi-20061115 (filename),usctheses-m40 (legacy collection record id),usctheses-c127-34224 (legacy record id),usctheses-m139 (legacy record id)

Legacy Identifier etd-Namburi-20061115.pdf

Dmrecord 34224

Document Type Thesis

Rights Namburi, Venkata Sri Kaliki Varma

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Repository Name Libraries, University of Southern California

Repository Location Los Angeles, California

Repository Email cisadmin@lib.usc.edu