SSS simulates light scattering under the surface of an object. Done right, it can have very convincing effects on many materials such as skin, stone, milk, etc. The downside is that it can be very expensive to render and takes a bit of tweaking to get right. If SSS is too expensive, there are multiple ways to fake the effect.

This tutorial will explain how to set up SSS and what each setting means. The information here is what I have figured out and what works for me. I might be totally wrong about some of this stuff, but it will give you a good starting point.

1. Make a new shader and assign it to the model that you want SSS on. I chose a PhongE for skin. Set up a
2 point lighting scheme with the key on the opposite side of the face from the camera and a strong back light to illuminate behind the ears. This will show off the SSS effect.

Download pdf Sub Surface Scattering (SSS) in RenderMan for Maya