Caustic reflections are very high frequency in space and for non-trivial geometry likely won't work well in real time (unless you fake it somehow). That said,

Caustic reflections are very high frequency in space and for non-trivial geometry likely won't work well in real time (unless you fake it somehow). That said, just rendering mirror surfaces or refractions doesn't require more than an extra ray per interaction (one in the reflection direction and one in the refraction direction). You can add a texture and get bumpy reflectons or refractions as well. The difference between these easy effects and the high spatial frequency caustic effects is indirect versus direct lighting. It's very easy to ray trace a a simple transparent model but a bright spot on the floor (e.g. [0]) below a reflective objects requires a lot of ray samples to capture directly. [0] http://news.povray.org/povray.binaries.images/attachment/%3C3d0337be%40news.povray.org%3E/Caustic-Ring.jpg http://news.povray.org/povray.binaries.images/attachment/%3C...