Monte Carlo light transport simulation
For this indoor scene lit by a sun/sky environment emitter, path tracing resolves most of the lighting well, but introduces high variance in the reflective caustic cast by the mirror. ERPT and RJMLT resolve the caustic better, but do not handle diffuse lighting well and introduce noise and temporal flickering. Our method uses MLT to only resolve the difficult paths using bidirectional path tracing, and handles everything else with path tracing, leading to significantly improved MSE (relative MSE shown in insets) and vastly reduced temporal flickering. Scene ©SlykDrako.