A very fast approximation to large-kernel Gaussian blur with nonuniform blur radii, by making use of box-filtered mip maps (theoratically related to Haar wavelet tranforms). The mathematical model can be found in the PDF file.
Hot keys:
[F1] show/hide FPS
[Space] pause/play animation
[P] pipeline type switch
Prerequisite: https://github.com/StarsX/XUSG