How can one go about making the fog box not way grainy. I've cranked samples very high (both in XPU and CPU) and made sure the lights weren't in the volumes (I read somewhere that makes a difference), but the improvement has been negligible. I'm using a light filter gobo. I tried the denoiser and it helps far away from the source but the god rays go all warbly nearer the source. What magic box am I not ticking or magic number tweaking?