1. J. Arvo, Backward Ray Tracing, SIGGRAPH’86 Course Notes — Developments in Ray Tracing, vol. 12, 1986.
2. The light volume: an aid to rendering complex environments;Chiu,1996
3. Radiosity and Realistic Image Synthesis;Cohen,1993
4. Original approach to produce soft shadows and account for diffuse interreflections in ray tracing;Debelov,2001
5. Light meshes — original approach to produce soft shadows in ray tracing;Debelov,2002