ray tracing

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 backwards 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.

{Usenet} newsgroup: {news:comp.graphics.raytracing}.

{(http://www.cm.cf.ac.uk:/Ray.Tracing/)}

(1996-05-29)