Eric P. Lafortune and Yves D. Willems
Proceedings of the Fifth Eurographics Workshop on Rendering, Darmstadt, Germany (June 1994), pp. 163-171.
Published as: Photorealistic Rendering Techniques, G. Sakas, P. Shirley, S. Müller (editors), pp. 168-176.
Ray tracing algorithms often approximate indirect diffuse lighting by means of an ambient lighting term. In this paper we show how a similar term can be used as a variance reducing technique for stochastic ray tracing. In a theoretical derivation we prove that the technique is mathematically correct. Test results demonstrate its usefulness and effectiveness in practice.
This paper is available on-line as a gzip'ed Postscript file (10 pages, 81 KBytes, expands to 185 KBytes).