Real-Time Volumetric Light Shafts
Lately, I have replaced the recently added screen-space light shaft algorithm with a new one because I was not satisfied with the results. The new method uses ray marching with interleaved sampling of the shadow map to simulate single scattering in participating media in real-time, thus, it produces more realistic results with relatively low cost.
The implementation calculates sample values in a separate pass to a new framebuffer, and then it collects the samples at the light combiner pass. The interleaved sampling is performed using a hand-crafted 8×8 pixel grayscale image containing random pixels with uniform value distribution.
There are some images with the results.