<graphics> A technique used in computer graphics to create realistic images by calculating the paths taken by rays of light entering the observer's eye at different angles. The paths are traced backward from the viewpoint, through a point (a pixel) in the image plane until they hit some object in the scene or go off to infinity. Objects are modelled as collections of abutting surfaces which may be rectangles, triangles, or more complicated shapes such as 3D splines. The optical properties of different surfaces (colour, reflectance, transmitance, refraction, texture) also affect how it will contribute to the colour and brightness of the ray. The position, colour, and brightness of light sources, including ambient lighting, is also taken into account. Ray tracing is an ideal application for parallel processing since there are many pixels, each of whose values is independent and can thus be calculated in parallel. Compare: radiosity. Usenet newsgroup: news:comp.graphics.raytracing. http://directory.google.com/Top/Computers/Software/Graphics/3D/Ray_Tracing/. (2003-09-11)

Ray tracing is a method for calculating the path of waves or particles through a system. The method is practiced in two distinct forms:

In 3D computer graphics, ray tracing is a technique for modeling light transport for use in a wide variety of rendering algorithms for generating digital images.