Multi-Pass Pipeline Rendering: Realism for Dynamic Environments

A coordinated use of hardware-provided bitplanes and rendering pipelines can create fast ray traced quality illumination effects for dynamic environments by using Multi-pass Pipeline Rendering (MPR) techniques. We provide recursive reflections and refractions through the use of secondary viewpoints and projective image mapping. We extend the traditional use of shadow volumes to provide global direct illumination effects which fit into our recursive viewpoint paradigm. Hardware surface shading is fit to a physically-based BRDF to provide a better local model, and the framework permits incorporation of indirect illumination as well. Furthermore, material transmittance is approximated using an extension to projective textures. Together, these techniques provide a platform for producing realistic images in highly dynamic environments. While most appropriate for scenes which specular components contribute largely to the secondary illumination, the integration of MPR with indirect radiosity solutions also provides a dynamic solution for highly diffuse environments. These techniques are immediately applicable to areas such as walkthroughs, animation, and interactive dynamic environments to produce more realistic images in near real-time.