bsdf sssapprox(vector albedo, float meanFreePath, float roughness, float scale, ...)
Average surface reflectance.
Average distance between scattering events.
A value from '0.0' to '1.0' blending to an ideal diffuse transmission reflectance profile.
Physical scale of the material. Smaller scale values will make the material more transmissive.
See writing a PBR shader for information on BSDFs.
Models SSS illumination based on an approximate reflectance profile.