Demonstration of SVGF for real-time path tracing

This is a follow-up video from my previous video, where I showed an initial version of my path tracer. This time, a bunch of changes and optimizations have been done. Most noteworthy, the addition of filtering algorithms, à la spatiotemporal variance guided filtering (SVGF), by Schied et al., have been implemented. The implementation is still in its early stages, in terms of performance, but also in terms of the visible artifacts. For instance, the shadows are rather overblurred and there are some temporal instabilities that occurs, most likely due to failed reprojections because of temporal discontinuities.