| Realistic shadows present a difficult problem in real-time rendering. While techniques for rendering hard edged shadows from point light sources are well established, attempts to incorporate soft shadows typically suffer from inaccuracies or poor performance.;Our algorithm makes use of recent advances in GPU randomization to perform Monte Carlo sampling of points on an area light source. Rays are then traced to the sampled points, using the shadow map as a discretized representation of occluders in the scene. The accuracy of this method can be improved through the use of multiple shadow maps, which together are able to better approximate the scene geometry.;As with conventional shadow mapping, our method is performed entirely on the GPU, does not require any precomputation, and can handle fully dynamic scenes with arbitrary geometric complexity. The quality of the generated shadows is comparable to that of offline rendering algorithms such as ray tracing, while performance remains real-time, on par with existing techniques. |
