A beam tracing method with precise antialiasing for polyhedral scenes

Abstract

Ray tracing is one of the most important rendering techniques used in computer graphics. A fundamental problem of classical ray tracers is the well-known aliasing. With small objects, or small shadows, aliasing becomes a crucial problem to solve. Beam tracers can be considered as an extension of classical ray tracers. They replace the concept of infinitesimal ray by that of beam but they are generally more complex than ray tracers. The new method presented in this paper is a high quality beam tracer that provides a robust and general antialiasing for polyhedral scenes. Compared to similar beam tracers, this method has some major advantages: • complex and expensive computations of conventional beam–object intersection are entirely avoided, so an extension to some non polyhedral scenes such as CSG ones is possible; • usual approximations or complex approaches for refraction computations are avoided. Moreover, this method is entirely compatible with the usual improvements of classical ray tracing (spatial subdivisions or hierarchical bounding volumes).