Environment mapped refraction models for low cost scan-line rendering

A low cost and versatile refraction model for scan-line rendering algorithms is presented. The model is based on the theoretical optical path of a light ray through a generic lens. A Gaussian approximation is then used, together with Blinn and Newell approximation. These expressions lead to a family of approximations with a tradeoff between computational cost and optical precision. In this paper we implement acceptable approximations of refractions that can be computed with the same order of computational cost as standard reflections. Z-buffered environment map utilization and adapting existent reflection map implementations to compute refractions are also discussed. @ 1997 Elsevier Science B.V.