Pointclouds and brickmaps can improve the render performance greatly since they “bake” a 3d model with any shader data that is needed for the render just once, and can be used over and over again. In some cases the original model doesn’t even have to be used for the render, brickmap which is free...
This is a shader which fakes the sub surface scattering effect in RenderMan efficiently.
Here is the algorithm for the shader: