ambient-snow (voxpander2)

I figured, if my ambient lighting term is computed using simulation of particle deposition, I might as well draw it as snow. This version also has an all-new non-recursive refinement operation with tunable blur and grain. The input to this one was an 8x8x8 terrain bitmap. Now, how might one go about applying compression to volume tiles? For the occupancy bitmap you could probably get some gains from run-length encoding, but what about compressing the results of lighting? Quantize down to some low bit-depth and apply error diffusion to retain the grit?