Use of superposition material in genBSDF


Currently, I would like to use genBSDF to create BSDF data for a material that overlays plastic and mirror. However, even if I checked the created data on a simple flat plate with BSDFviewer, I could not confirm the effect of superposition, and the result was that only plastic was effective.

The following are the material settings and commands used.

void plastic test_p
5 0.167 0.167 0.167 0 0

void mirror test_pm
1 test_p
3 0.333 0.333 0.333

test_pm polygon object_1.1
12 1950 650 0
1950 0 0
0 0 0
0 650 0

genBSDF +f +b -c 500 -geom millimeter -dim 950 1000 300 330 -1 0 test.rad > test.xml

Does genBSDF not support superposition materials?
I would appreciate your reply.

Best regards

The “mirror” type does not superimpose materials. Rather, it uses a perfect mirror with the given reflectance for light sources in the scene, and substitutes the alternate material (if given) in all other interactions. Since the genBSDF tool does not use light sources in its calculation, it is no surprise that the behavior you get is for the plastic exclusively.

If you really want to mix the effect of two materials, I suggest using the “mixfunc” type, which can perform a blending of two different materials on the same surface.

Hi Greg,

I appreciate your quick response.

As you suggested, I will consider using the “mixfunc” type.

Thanks a lot,