I may be nit-picking here but as I understand it, Ray tracing (i.e. Bryce) is actually inverted from the real world because it shoots rays from the camera instead of receiving them. True Radiosity is a "real world" rendering technique where a scene is pre-calculated for all light rays (including bounces), with no reference to a camera. This pre-render can take hours but once done the camera can be placed anywhere in the scene and takes only minutes to render (and includes bounce data and data that is "off" camera). A lot of what people think of as Radiosity is just a radiosity subset or hybrid RT/Radiosity. Some of what Ornlu has been trying to recreate in the recent threads is Color Bleeding; the ability of a mirror to reflect light back into a room is called Caustics (Bryce has always had Refractive Caustics, btw); surrounding a scene with a sphere (for reflections) is called Image Based Lighting (IBL) and HDRI output uses floating point numbers to store color values rather the usual 0-255 integers used in the RGB model. Most often used with IBL. Of course, I'm just an amateur and any corrections would be appreciated (VBG). HTH- Dan