Hackernews posts about Ray Tracing

Ray Tracing is a rendering technique that simulates the way light behaves in the real world by tracing the path of individual rays of light as they interact with virtual objects and surfaces.

Related: the TI-84 CE  
  1. Spectral Ray Tracing (larswander.com)
  2. Ray Tracing in One Weekend (discourse.haskell.org)