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Won't Fix
Won't Fix in 2023.2.X
Votes
0
Found in
2022.2.0a18
2023.1.0a1
2023.2.0a1
Issue ID
UUM-2814
Regression
No
[HDRP] Enabling "Keep Quads" for model import breaks pathtracing
Repro:
Download and import the repro project here: https://drive.google.com/file/d/1JeBvhAx6SYw3f7xcfBR9IJJ7eJEWgULT/view?usp=sharing
- Open the Scene SampleScene.unity
- Observe the corruption in the Scene view, and the warnings in the console
- Select the asset FR_SectionA_01.fbx
- In the model's inspector, disable the option "Keep Quads" and apply
Observed:
When Keep Quads is disabled and the resulting mesh is triangulated, the pathtracer behaves as expected. It doesn't seem to like quads or ngons.
Expected:
Quads should be considered very likely and Unity does support this as an import option. The pathtracer should be able to handle meshes with non-triangle geometry. Or if it cannot, a meaningful warning should be displayed in the console to advise users how to fix the corruption.
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Resolution Note:
Low level APIs like DXR don't support QUAD meshes unfortunately.
I added an error message when QUAD meshes are used:
Cannot use a Mesh for building the RayTracingAccelerationStructure. Couldn't find any sub-meshes with Triangles mesh topology in Mesh '%s'."
QUAD meshes won't be added to the acceleration structure and thus will be invisible in ray tracing or path tracing.
Resolution Note (2023.2.X):
Low level APIs like DXR don't support QUAD meshes unfortunately.
I added an error message when QUAD meshes are used:
Cannot use a Mesh for building the RayTracingAccelerationStructure. Couldn't find any sub-meshes with Triangles mesh topology in Mesh '%s'."
QUAD meshes won't be added to the acceleration structure and thus will be invisible in ray tracing or path tracing.