VXGI was actually inspired by SVOGI, funnily enough.
Anyway, VXGI is really easy to get going now. Just grab the source from github, run the setup.bat without overwriting any of the files when prompted, then build the engine like usual and then build ShaderCompileWorker. Once you do all that, you’re ready to go, it’s almost the same as building the normal UE4 source at this point.
There are a few optimizations you can do as console commands if you really want to get some performance back when using it, like r.VXGI.MapSize = 32 will make the voxels much larger and make it run a lot faster even if it won’t be quite as accurate. There’s more you can do to get it running faster, but generally those options are all in the post process volume.
To enable VXGI to begin with, you need to pick a light (any type will do) and enable VXGI on the light, then enable VXGI diffuse (and specular if you want realtime non-screenspace reflections) in the post process settings.