pbrt v3 scene

[zhaoyangyang316]

Hi,

Is there any limitation on the scene file (pbrt v3)? I tried couple pbrt v3 scenes from the scene repository, and they all crashed the render. e.g. the breakfast scene here https://www.pbrt.org/scenes-v3_images/breakfast-lamps.jpg.

Is it possible to provide an example scene?

THanks
Yangyang

[Twinklebear]

Hi Yangyang,

Thanks for opening this issue, yes the support for PBRT scenes is very limited right now. I do have some error reporting when an unsupported scene is found but it will just throw an exception so you may not see anything logged on the console (I can fix that).

I tried running the breakfast-lamps scene and it looks like it contains some non-triangle meshes, I don't have support for triangulating those right now.

You should be able to run:

• Crown
• Landscape (the different view-*.pbrt files)
• Barcelona Pavilion
• Buddha fractal
• Chopper titan
• Ecosys (the materials look to import ok-ish here too)
• Ganesha
• pbrt-book
• San Miguel
• Veach bidir
• Veach mis
• Villa (though it looks like the ground is missing)
• VW van
• Whiteroom

However while these might run they won't match how the PBRT scenes look, as most of the materials/lighting parameters aren't mapped to their equivalents in ChamleonRT. I found that ecosys, pbrt-book and San Miguel look the closest to how they should look. GLTF and OBJ scenes are much better supported overall in terms of materials.

[zhaoyangyang316]

thanks! I will check them out later.

BTW, is ChamleonRT only supporting direct illumination?

[Twinklebear]

ChameleonRT is a full path tracer, but the support for loading lights from a scene is pretty limited (basically only from my custom CRTS format right now, and maybe some in PBRT?). I also generate a kind of checkerboard environment light map around the scene to provide additional lighting. There's also a bug in the light weighting to keep in mind in the path tracer that I need to fix at some point #11 , and transparency doesn't quite work #3 .

So it is a path tracer, but with some bugs :) . I've been procrastinating fixing these a bit while I work on https://github.com/Twinklebear/ChameleonRT-lang , which would eventually let me have a single host/device code implementation of ChameleonRT, so I could fix the bugs once instead of 5 times porting a fix to each backend

[zhaoyangyang316]

thanks!

I'm more of a light transport researcher (with limited knowledge of various RT frameworks). I was trying to get to know real-time ray tracing frameworks and come across ChameleonRT.