alpha = roughness squared in microfacet BRDF

[Feez2403]

Hello again :)

I am looking into the BRDF you are using.

Why is alpha = roughness squared (gamma(x) ^2) in your work ?

The original paper https://www.graphics.cornell.edu/~bjw/microfacetbsdf.pdf
just takes alpha values without squaring them.

Is it just a way to remove negative roughness when training ?

[FrozenBurning]

Thanks for your interest in our work! We refer you to the implementation of the BRDF used in NeRFactor.