Experiment 5 - Research-lite HDR analysis as a guide to illustrate potential of V-RAY rendering in daylight design
ARCH 510 Kevin Van Den Wymelenberg Yan Meng
Real Scene Photography Experiment Process
Take real HDR Photo
Rebuild same scene in Rhino
Measure and apply material reflectance
Set the same light source condition through VRAY
CIE overcast sky at same time
Compare analysis in HDR
Conclusion
Experiment step 1 Real scene Compare(RGB Rendering result)
Lawrence 278 Location Time 03/02 10:34 AM
Scene 1
Partial Cloudy Camera B (Canon EOS 5DIII) Sigma Lens Fish-Eye F11 ISO 100 WB 6400 Shutter Speed Sequence 1/4000 --- 30s Luminance Pre 24 cd/m² Luminance Post 25.3 cd/m²
Location Experiment step 1 Real scene Compare(RGB Rendering result)
Lawrence 278
Time 03/02 10:37 AM
Scene 2
Partial Cloudy Camera B (Canon EOS 5DIII) Sigma Lens Fish-Eye F11 ISO 100 WB 6400 Shutter Speed Sequence 1/4000 --- 30s Luminance Pre 9.24 cd/m² Luminance Post 10.4 cd/m²
Location
Lawrence 278
Experiment step 1
Time 03/02 10:42AM
Real scene Compare(RGB Rendering result)
Partial Cloudy
Scene 3
Camera B (Canon EOS 5DIII) Sigma Lens Fish-Eye F11 ISO 100 WB 6400 Shutter Speed Sequence 1/4000 --- 30s Luminance Pre 19.26 cd/m² Luminance Post 19.51 cd/m²
Experiment part 2 Total light channel rendering VS Original zero close to real condition
Use total light renderings, we try to simulate real scence light. The result we get is that the surface close to the main reflectance area is close the real reflectance condition. However, where the spot far away from reflective surface, the result of rendering and false color diagram is very low.
low
1930 234
121 40
12
80
1857 76 18
3
Experiment part 2 Total light channel rendering VS Original
81
76 1795 23
8
22 298
1944
28 7
1
84
Experiment part 2 Total light channel rendering VS Original
45
202 2002
79
46
16
1871
55 16
1
Experiment part 3 HDRI SKY Background Rendering VS orginal Use HDR dome sky as light source, make rendering and false color. The spread of light is close to the real scence.
286
1893
196 265
2063
175
79
86
16
8
Experiment part 3 HDRI SKY Background Rendering VS orginal
43
66
65
243
20 2058
1770 26
6
1 4
164
Experiment part 3 HDRI SKY Background Rendering VS orginal
176
1930
93
65
254
103 2061
79 57
2 12
120
Experiment part 3+ Total light channel vs HDRI sky
Same range
Total light result
HDR dome sky result
Experiment part 4 Manual added reflecting wall vs real scene condition
Orginal
Render
Experiment part 4 Manual added reflecting wall vs HDRI sky
HDRI Dome
Reflector wall
Conclusion: The vray rendering light sources more focus on the diffusing light on material surface. RGB channel is not applicable in the hdr light study Total light channel is a render channel consider the light particle within the rendering which is usable. No sky reflection or refraction would be considered in vray rendering. The render light source is single sourced even setup as CIE overcast. No other source would be considered. The HDRI dome sky replaces vray sunlight is a good way to improve the light quality when bring to hdr analysis yet still off a little bit.