Realtime Caustics using Distributed Photon Mapping

illumination algorithms we are now able to render the most important
illumination effects at interactive rates. One of the major remaining
issues is the fast and efficient simulation of caustic illumination. The
photon mapping algorithm is a simple and robust approach that generates
high-quality caustics. However, photon mapping has a number of
properties that make it rather slow on today's processors and it has
also been notoriously difficult to parallelize efficiently.

This talk presents a detailed analysis of the performance issues
of photon mapping together with significant performance improvements for
all aspects of the photon mapping technique. The solution forms a
complete framework for realtime photon mapping that efficiently combines
realtime ray tracing, optimized and improved photon mapping algorithms,
and efficient parallelization across commodity PCs. The presented system
achieves realtime photon mapping performance of up to 22 frames per
second on non-trivial scenes, while still allowing for interactively
updating all aspects of the scene, including lighting, material
properties, and geometry.