Implementing Energy Redistribution Path Tracing

Energy redistribution path tracing is a recent approach to performing global illumination that combines basic Monte Carlo path tracing with elements of Metropolis Light Transport in order to achieve the advantages of each. The result is an algorithm with reduced variance, better stratification, and the ability to handle direct lighting, indirect lighting, and caustics with a single method. It is also conceptually simpler than Metropolis, and eliminates several of the disadvantages of traditional MLT, such as start-up bias and poor convergence for direct illumination. This project describes the details and results of an implementation of ERPT within the framework provided by the freely available, educational renderer, PBRT.