Simple surbsurface scattering

Here's a simple implementation of a subsurface scattering effect as presented by Chris Bernardi (Pixar) in the Siggraph 2003 course notes, "Shading a coral reef". It's based on a simple illuminance() loop and requries no raytracing - therefore it's fast. Compared to implementations that are based on photon mapping or excessive ray tracing, this one sure isn't nearly as accurate - instead it's a pragmatic approach that simply aims for a good look with low render times.

The file:

You can download the shader node and a sample scene here. It requires Pixels:3D V5.