Using Procedural RenderMan Shaders for Global Illumination




Global illumination techniques like radiosity or Monte-Carlo ray-tracing are becoming standard features of
rendering systems. However, there is currently no accepted interface format which supports an appropriate
physically-based scene description. In this paper we present extensions to the well-known RenderMan interface,
which allow for a physically based scene description and support advanced global illumination techniques. Special
emphasis has been laid on the support for procedural descriptions of reflection and emission by RenderMan
surface shaders. So far, they could not be used with most global illumination algorithms. The extensions have
been implemented in a physically-based rendering system and are illustrated with examples.