RIRE stands for: Renderer Inside REnderer.
It also means that it is a renderer ‘pour rire’, (French expression meaning ‘not for real’).
RIRE is a Brute Force Naive Path Tracer, entirely written in OSL, and could be run (with some adjustments) on any good OSL Renderer, like AppleSeed or Cycles.
Just put a plane in front of your camera, and watch through the RIRE Rendering!
It is made only for educational purpose! It has absolutely no pretention for production, not even being fast. It is just to show and understand how a Path Tracer is made.
Indeed, here are the first results from the first version :
Real scene, 64 bounces:
To be continued...