contains articles and product reviews related to making music using computers and creating 3D computer animation in sync with music. is also the home page of  Donald S. Griffin, an experienced professional composer, sound effects designer and audio consultant with an emphasis on computer games,  video games and internet music and sound effects. For pricing and contract availability send email to: DGriffin (@) Computer-Music (.) com  contains articles and product reviews related to making music using computers and creating 3D computer animation in sync with music. is also the home page of  Donald S. Griffin, an experienced professional composer, sound effects designer and audio consultant with an emphasis on computer games,  video games and internet music and sound effects. For pricing and contract availability send email to: DGriffin (@) Computer-Music (.) com

Radiosity Tests

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Donald S. Griffin - Computer Music Consulting, composer of professional quality original interactive music and sound effects and consultant for computer games, multimedia and the world wide web. Articles and product reviews.

trueSpace Radiosity Tests
Mostly modeled in Rhino. I am starting to experiment with modeling in Rhino then doing quick renders in Carrara then more complex ones in tS.

1st Radiosity tests:
The images in this table are tests using radiosity on a Rhino model I built just for this purpose. The Solid plane is just large enough to extend outside of an environment sphere I made using Infinity. The sphere and plane were not excluded from the radiosity solution. I am not sure how much effect the sky had on the colors of the building but am confident the brownish tint visible in the underside and front of the roof are from the brown ground. I can't think of where else it could come from. The sun light is very slightly yellow and the sky light is very slightly cyan.

The first two rows are the final product. I probably should have reduced the sun light more but I got tired of this test and learned what I wanted to learn. I settled on using quality of 1. After a while I found that convergence was set at 99 and because of the cryptic name I didn't realize that is the percentage at which the radiosity solution quits. Much of the action happens around 99.96% so that was too low. I set it to 100 so I can just quit the solution when the test renders look good. I found the light spots on the floor did not render unless I quad-divided it and the more I did the better the square shapes looked. I found when I turned up the sky light too high the detail near the bottom front of the roof would disappear like it was smoothed out of existence. I had to keep in below one sixth on the slider. I think the sun was set at two thirds on the slider, probably too bright as the results seem to show. I found a quality setting of only 1 gave me a usable solution as early as 40 steps or so. But continued to reveal detail in the ceiling right up to 99.99 percent which was up between 5,000 and 8,000 steps. So for some uses radiosity can be quick. For new users it is worth noting that I consistently had to wait almost 8 minutes before the radiosity solution showed 1 step completed, but after that the counter started going up faster than 1 step per second on my PIII 500. While it was doing that first step doing a CTRL-ALT-DEL would show trueSpace not responding. This does not always mean a program is not working (locked up) especially in trueSpace which seems to do this in several cases. Busy and not answering your calls.

The third row shows why I needed radiosity, direct light, and sky light to illuminate the important parts of the model. I could have gone without ray tracing and added fill lights but to get the whole model just right would have been a real pain. If you are doing animation you can use this to create a lighting reference of how things should look so you have something to compare to when you place fill lights for simple ray tracing.

Front view. Ceiling hole light. Angle view. Up at ceiling.  
TSdon153-01 Arch-Front 800x600.jpg (53610 bytes) TSdon153-01 Arch-Floor 640x480.jpg (58307 bytes) TSdon153-01 Arch-FrontRtUpAngle 800x600.jpg (61693 bytes) TSdon153-01 Arch-Ceiling 800x600.jpg (49924 bytes)  
Side view. Through skylight. Column bases. Detail view.  
TSdon153-01 Arch-OutsideFull 800x600.jpg (62219 bytes) TSdon153-01 Arch-DnThruRoof 640x480.jpg (54454 bytes) TSdon153-01 Arch-Floor&FtrDetail 640x480.jpg (49246 bytes) TSdon153-01 Arch-Front&HdrDetail 640x480.jpg (28284 bytes)  
Sun, No Radiosity. Sun. Radiosity. Sun. Radiosity. Sky. Radiosity. Sky. Radiosity.
TSdon142-04 ArchRoofTex noRad.jpg (22942 bytes) TSdon149-01 ArchSunVBriteDnsFlr r9full.jpg (26668 bytes) TSdon149-01 ArchSunVBriteDnsFlrFloor r9full.jpg (8846 bytes) TSdon151-01 ArchSkyONLYDnsFlr r7full.jpg (32233 bytes) TSdon151-01 ArchSkyONLYDnsFlrFloor r7full.jpg (13690 bytes)


2nd Radiosity tests. Focusing on what radiosity does to bumps maps:
The images in this table are tests to see how bump mapping holds up when using radiosity. The texture is the Darktree flagstone texture. A single distant light in the default, overhead position. No other objects in the scene. I am not sure how adding objects or lights would affect things but more even light will fill in shadows so it should make bump map effects less noticeable they same as you would find without radiosity. This was meant to test whether bump map effects seem to be present at all using radiosity.

tS default sphere. No Radiosity. Radiosity quality=9 full solution. Radiosity quality=1 full solution.
TSdon155-01 RadBumpBallTest.jpg (21132 bytes) TSdon155-01 RadBumpBallTest r9-f.jpg (16386 bytes) TSdon155-01 RadBumpBallTest r1-f.jpg (16350 bytes)
Cube subdivided 4 times in Thermoclay. No Radiosity Radiosity quality=9 full solution. Radiosity quality=1 full solution.
TSdon155-02 RadBumpBallTest.jpg (18692 bytes) TSdon155-02 RadBumpBallTest r9-f.jpg (15037 bytes) TSdon155-02 RadBumpBallTest r1-f.jpg (15039 bytes)


3rd Radiosity tests including my fake radiosity trick:
The images in this table illustrate a new trick I figured out for faking some of the effects of radiosity.

Distant Light. No Radiosity. Distant Light. Radiosity. Distant Light. Radiosity. Too dark. Same with tone mapping set from 1 to 2. Distant light and two big area lights at intensity+10. No radiosity. Coincidentally very similar exposure to the one on the left. Same as on left but larger view. Note how roof is lighter for the bottom 1 meter. This is where I placed the down-facing area light. 
TSdon157-05 PotReduced+Arch NoRad.jpg (34915 bytes) TSdon157-06 Pot+ArchNoSky r1-f main.jpg (31489 bytes) TSdon157-06 Pot+ArchNoSky r1-f pot.jpg (22988 bytes) TSdon157-06 Pot+ArchNoSky r1-f pot tm2.jpg (34657 bytes) TSdon158-02 Pot+ArchAreaFakeSky Pot.jpg (38694 bytes) TSdon158-02 Pot+ArchAreaFakeSky Main.jpg (45682 bytes)
Area light moved higher. Sun brighter, shadow mappings set to low detail by accident. Shadow map trouble with higher settings. Can't remember which. Shadow map set to high settings. Trouble with shadow mapping producing wild and unpredictable results. This is the best it got. Back to Radiosity. Increased mesh density on all objects, especially floor. Sun=1.0 Sky=0.1 & no shadows. Same but close-up of pot.
TSdon158-02 Pot+ArchAreaFakeSky MainHi+MapLo.jpg (45093 bytes) TSdon158-02 Pot+ArchAreaFakeSky MainHi+Map.jpg (42979 bytes) TSdon158-02 Pot+ArchAreaFakeSky MainHi+MapHi.jpg (41464 bytes) TSdon158-02 Pot+ArchAreaFakeSky MainVHi+MapAllMax.jpg (45329 bytes) TSdon159-04 Pot+ArchSunSkyNS r1-Main.jpg (58687 bytes) TSdon159-04 Pot+ArchSunSkyNS r1-Pot.jpg (53188 bytes)


3rd Radiosity test conclusions:
Radiosity looks good but screws up bump mapping but its fill effects are hard to achieve using fill lighting because they are nice and uneven. Ray tracing without radiosity produces hard shadows that really don't look that good but learning to control mapped shadows may be harder than dealing with radiosity. My trick with area lights took so long to render it made radiosity look a lot more practical though the textures looked better with my trick since it was NOT radiosity.

In the future I will probably choose radiosity where bump mapping is not important and ray tracing with area lights or light arrays to produce soft shadows when bump maps DO matter. Later I hope to tame the wild beast that is shadow mapping and turn it away from the dark side of The Force.

This whole odyssey has taken way more time than I expected, partly because my desire to use models instead of simple shapes for my testing. But I think the models served the purpose of showing me where and why I would want certain characteristics in my light and shadows so it was probably worth the extra time. These test also left me a bit depressed that CG is not as far along as I had previously thought. I would much prefer to put up an object I call a sun and have its light behave like a real sun in every way unless I desire something different. Now that I know better how much will be wrong with my images I am less excited about producing them even though I now know enough to make them much better. 


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