Essential Guide to RenderMan® Shading Plugin Development: Understanding Bxdfs

© The Author(s), under exclusive license to APress Media, LLC, part of Springer Nature 2023

B. E. HollisterEssential Guide to RenderMan® Shading Plugin Developmenthttps://doi.org/10.1007/978-1-4842-9392-8_8

8. PDF Normalization, Sampling, and Anisotropic Bxdf

Brad E. Hollister¹  

(1)

Carson, CA, USA

 

This chapter concludes the book with some representative anisotropic Bxdf plugins.

First, though, we start by describing step by step how to calculate the PDF for the uniform and cosine distributions about a hemisphere and how to draw random vectors from those distributions. This was previously only discussed at a high level to allow for focusing on the RenderMan execution environment. However, a PDF value is required whenever you are “generating” samples ...