Hi,

I was wondering if anyone had any luck using the Thinfilm BSDF

I have tried layering it on top of dielectrics, conductors and diffuse BSDFs as well as using it on its own (which is not expected to work) And I haven’t had any luck.

I mentioned this in the MaterialX Discord Server’s Solaris chat and it seems no one else there has had any luck with the BSDF either.

If it is functional it would be great to see an example of it working.

Best
Rich

it seems to be working over Dielectric BSDF if the IORs differ, just simply based on observation how or when it shows up on Standard Surface
just CPU though

Great!

I can seem to get it working now with the Dielectric, I just had the scatter mode on transmission not transmission and reflection or just reflection. When the reflection is enabled it works as expected so that's a silly mistake on my end as the thinfilm bsdf just modifies the specular reflection lobe as mentioned in the spec. This is why it shouldn't work with diffuse but should work with dielectrics and conductors.

Still not too sure why it doesn't work with a conductor though, this will need to be changed since the lama node defs have thinfilm layered on top of the conductor so for any kind of lama support this would need to work. I'm hoping this is just to do with the nodedefs that created the VOP nodes and when updating to 1.38.2 and above then regenerating the VOP nodes this will work.

Best,
Rich

Unrelated to the general use of the BSDF but where my main issue was stemming from was that it seems although the thinfilm BSDF can take floats. when plugging a constant into the thickness and IOR it seems to break so I am going to submit a ticket in regards to this.