Bug Pathtracing and 3dsMax Physical Material doesnt work together

hey, as you might have seen, 3dsMax Physical material in Unity is nothing else than a shader graph using stacklit as a base.
Since Pathtracer supports stacklit, this should not be a problem aside from the few node unsupported in raytracing (mostly derivative like normals from texture.. etc), which the default graph uses by the way.

However, I had a quick look and there is one exposed parameter (coat weight which controls coat mask value) when equal to zero that will create a black render (like the material's not supported).
Putting anything above zero fixes the problem so while we have a look, you can try and see if this workaround works on your side.

Thanks for the feedback

 

Yes something's not right. A bug has been created and is being investigated.

I'll have a look for the UI one while we're at it.

 

The previous issue have been fixed with this PR and robustness have been improved for the stacklit support as a whole thanks to your feedback.

For speed tree, this is actually different but still interesting. It's not black because the material is unsupported, it's black because the normal data are most probably null.

Speed tree uses a shader graph with a lit master node and this graph uses Custom Interpolator to pass data (Normal / Tangeant / Bitangent in world space) from the vertex to the pixel shader stage. Those custom interpolator doesn't seem to be supported with pathtracer and the doc hasn't been updated yet.

I'm no expert but in this case, using normal / tangent / bitangent nodes instead of these interpolators seem to be producing the same result and fix the path tracer black issue. So while we investigate if there is proper reaons on why these are used, there's a workaround.