...
Diffuse exponent controls the diffuse falloff. It is a power exponent. Higher number gives us sharper falloff. For example, on the moon surface, you can set a high exponent to produce a sharper falloff.
| Note |
|---|
Diffuse exponent only applies to the Lambertian diffuse, that is, when roughness is 0.0. Combining diffuse exponent with Oren Nayar roughness does not make sense so it will be ignored when roughness is > 0.0. |
...