A rendering method that simulates light reflections, refractions and shadows. It follows a light path from a specific source and computes each pixel in the image to simulate the effect of the light. It is a very process-intensive operation. See reflection mapping and radiosity.
Many of the first graphics simulations were done at the University of Utah, and this is one of them. The shadows in this picture were created by software algorithms that simulate a beam of light from a designated source. (Image courtesy of Computer Sciences Department, University of Utah.)
Modern-day Ray Tracing
This image created in MicroStation Modeler and rendered in the MasterPiece visualization program contains the kinds of realistic shadows and reflections that make a digital object photorealistic. As good as this looks, this picture was reduced to only 256 colors for online and CD-ROM presentation. (Image courtesy of Bentley Systems, Inc.)
The Most Realistic
Although incredibly computation intensive, ray tracing provides the most realistic shadows, reflections and refractions. (Image courtesy of Intergraph Computer Systems.)