Ray Tracing: Whence and Whither?

by Dave Edwards

A talk given at Grove City College

April 24, 2008


In 1980, Turner Whitted introduced a rendering technique known as ray tracing to the computer graphics community. This ray-based technique was a software alternative to the raster-based rendering methods that already existed in hardware at the time. For the following 20 years, ray-based renderers were used to produce high-quality images with long render times, while raster-based methods were used for interactive programs.

In recent years, changes in hardware and software have allowed ray-based rendering software to run at interactive rates for some applications. An important current debate in the computer graphics community is whether ray-based rendering has a future an interactive applications, and if so, to what extent.

I will give an overview of the ray tracing algorithm, and explain how Whitted's original method may be extended to include features such as motion blur, soft shadows, and depth of field effects. I will talk briefly about our research into the perceptual issues involved with ray tracing, and evaluating the quality of images in general. Finally, I will mention some of the major open problems in interactive ray-based rendering.

Slides (PDF)


Whitted, T. An Improved Illumination Model for Shaded Display. Communications of the ACM 23, 6 (June 1980), 343-349.

Cook, R. L., and Porter, T., and Carpenter, L. Distributed Ray Tracing. In SIGGRAPH '84: Proceedings of the 11th Annual Conference on Computer Grapics and Interactive Techniques, 1984, pp. 137-145.

Pohl, D. Ray Tracing and Gaming - Quake 4: Ray Traced Project. PC Perspective Online Article, December 18, 2006.

Pohl, D. Ray Tracing and Gaming - One Year Later. PC Perspective Online Article, January 17, 2008.

Shrout, R. NVIDIA Comments on Ray Tracing and Rasterization Debate. PC Perspective Online Article, March 6, 2008.

Shrout, R. John Carmack on id Tech 6, Ray Tracing, Consoles, Physics, and more. PC Perspective Online Article, March 12, 2008.

Shrout, R. Crytek's Cevat Yerli Speaks on Rasterization and Ray Tracing. PC Perspective Online Article, April 10, 2008.

Stokes, J. Clearing up the confusion over Intel's Larrabee. Ars Technica Online Article, April 26, 2007.