sorry bit of a cross post but not sure where to stick this:
I noticed in some white furnace test in Create that my own hand rolled MDL materials - and indeed the built in PBR surface - exhibit the traditional darkening on grazing angles at high roughness - presumably due to microfacet shadowing BSDF’s not accounting for multi scattering effects (which is a well know problem with microfacet bsdfs in general)
In the MDL docs however there appears to be a specific term added to compensate for this: multiscatter_tint() in the bsdfs it provides (pretty much all of which are microfacet based)
However setting this doesn’t seem to have any effect in Create - it doesn’t throw up any compiler errors either…
can anyone from Nvidia confirm if this just isn’t implemented in Create right now?
example below illustrates the problem:
If the multiscatter_tint() mechanism is working, I presumably shouldn’t be getting any darkened areas on these spheres - or it should be less in any case (my shader on the left which implements multiscatter_tint: color(1.0), the native PBR shader on the right)