For the visual studio thing, if cloned the repo correctly from the page (following Epic’s instructions), you should have everything setup so that it works automatically.
You need to create two post process volumes, one set it as the bounds (check DefinesAHRBounds). That represents the extents of your scene. On the other one just mess with the Approximate Hybrid Raytracing tab.
You could check the video I have on the first post, but it’s quite outdated. Still, it should help to get the basics down. I really need to do a new one, but with studies and all it’s being pushed back.
That’s whats neat, the memory increase is small, cause the mip level map (really, it sounds wrong. If someone can suggest a more catchy name, I’m all ears) is just 8 bits per component (could even cut it to 4, but think the overhead on tracing won’t be worth it), and the scene volumes mip map are binary, so only one bit per voxel (currently it’s using a whole byte, but that’s because it was the fastest way to implement it, will change it in the next few days).
Performance is much more constant now, because just a few samples are enough, and it scales better with the voxel size decreasing. Overall I get about 2 - 3 times faster tracing, depending on settings. I really need to come up with a standardized bench that I can distribute and use to test improvements and performance on different computers.