US Patent 10991079 Using previously rendered scene frames to reduce pixel noise

This disclosure presents a method to denoise a ray traced scene where the ray tracing uses a minimal number of rays. The method can use temporal reprojections to compute a weighted average to the scene data. A spatial filter can be run on the scene data, using the temporal reprojection count to reduce the size of the utilized spatial filter radius. In some aspects, additional temporal filters can be applied to the scene data. In some aspects, global illumination temporal reprojection history counts can be used to modify the spatial filter radius. In some aspects, caustic photon tracing can be conducted to compute a logarithmic cost, which can then be utilized to reduce the denoising radius used by the spatial filter. The modified and adjusted scene data can be sent to a rendering process to complete the rendering to generate a final scene.