Rough Glass Simulation

I made use of the importance sampling technique described in the following paper in order to more accurately simulate ground/rough glass and glossy mirrored surfaces:

https://www.cs.cornell.edu/~srm/publications/EGSR07-btdf.pdf

The paper describes an extension of the widely used Cook-Torrance BRDF (which I use as my "default" shading algorithm for "normal" materials) and extends it into a BSDF (a Bidirectional Scattering Distribution Function) which is the sum of a BRDF and a BTDF (Bidirectional Transmissive Distribution Function).


Here are some of my results: