Which includes the anisotropy discussion as part of the description of the NDF.
I think this helps to frame the discussion as we refer to BSDFs with Fresnel and GGX in many places, and this introduces where those terms actually apply in the microfacet model (which we assume for the metal, dielectric, and coat interfaces).
I cleaned up the anisotropy/NDF math a bit, to its simplest form which is all that is relevant here, to describe how our roughnesses are related to the alpha parameters in GGX.
I moved the notes on alternative anisotropy parametrization to a "open questions" box, to make the main text read more coherently.
Added a short note about microfacet multiple scattering (with basic references), as this is practically important to implement.
virtualzavie
commented
1 year ago
Which includes the anisotropy discussion as part of the description of the NDF.
I think this helps to frame the discussion as we refer to BSDFs with Fresnel and GGX in many places, and this introduces where those terms actually apply in the microfacet model (which we assume for the metal, dielectric, and coat interfaces).
I cleaned up the anisotropy/NDF math a bit, to its simplest form which is all that is relevant here, to describe how our roughnesses are related to the alpha parameters in GGX.
I moved the notes on alternative anisotropy parametrization to a "open questions" box, to make the main text read more coherently.
Added a short note about microfacet multiple scattering (with basic references), as this is practically important to implement.