
Simulating Absorption Using Depth Maps
Approximating light absorption inside translucent objects using their depth as seen from the light.
Almost every material in the real world is slightly translucent: light enters the surface, scatters inside, and leaves somewhere else. Simulating that accurately is too expensive for real time, so games rely on approximations.
Below are the techniques I implemented in Unity, from a fast precomputed thickness map to a depth-based method that measures thickness at runtime.

