In my, what seems like never ending, journey to understand Rendermans BxDF plugins I thought it a good idea to practice come of what I have learnt. In doing so I have implemented the 3 microfacet models presented in Microfacet Models for Refraction through Rough Surfaces. These consist of,

Blinn – https://github.com/DeclanRussell/PxrBlinn

Beckmann – https://github.com/DeclanRussell/PxrBeckmann

GGX – https://github.com/DeclanRussell/PxrGGX

I’m hoping at some point to do a tutorial/blog post explaining renderman plugins and some of the maths involved to create these plugins.

In the meantime however some good resources I used include:

Renderman Plugins – https://community.renderman.pixar.com/article/1088/developing-ris-plugins.html?l=t

Some helpful information about BxDF sampling – https://agraphicsguy.wordpress.com/2015/11/01/sampling-microfacet-brdf/