Rendering surfaces in RenderMan relies on a single layerable material called PxrSurface.
This is the same material model used in Pixar Animation Studios' feature animation. As such there are some important benefits to this material:
As an artist, being able to choose a single material for all your shading eliminates guesswork and allows RenderMan to optimize as needed. Below we discuss all the different settings and their relevance to making certain materials. Pay special attention to notes about performance considerations as well as hints on what combinations will be