For the curious, https://en.wikipedia.org/wiki/Spherical_harmonics. Some serious voodoo math involved, but once you get the concepting down, it's a startlingly efficient way of encoding directional lighting information for an entire sphere of directions into a handful of Colors. For example, second order SH uses only 9 ColorFs to encode pretty much every possible direction of lighting in a full sphere, with minimal gaps or missed data.
Got the bulk of the stuff in last night, but ran into an issue where it was *mostly* encoding ok, but one band was getting corruption and blowing out to full white. So i'll be taking a further look at that. Worst case, I have a few other implementations of SH I can test and see if they give better/more consistent results. When I get something locked in, I'll definitely be posting some screens/video