Raytracing is a method of creating life-like scenes in computer graphics. It is a way of generating near photo-realistic pictures from a series of commands in a text file. A ray of light is traced from the hypothetical viewer's eye, through the image plane to an imagined object on the other side. How the light is affected by the object and its surroundings determines the value of the individual pixel the ray passes through.

Good examples can be seen at the Internet Ray Tracing competition. Some films use raytracing for the creation of effects and scenes.

Raytracing is not much use for computer games, because it can take several minutes to create a single image. It's used in industry for engineering and architectural visualisation. It is used a lot in art as well.

Commercial and freeware software is available for many computer systems for raytracing. In all cases, the faster the computer you have the better... and you will need a fast computer!