Note that the global ambient term is ONLY for rendering while calculating because it will approach zero as the calculation nears completion. I tried triangles first because Their area is easy to calculate. The triangle patches stay exactly within the boundaries of the region of the light map of the polygon they're associated to. Go ahead, say it six times fast, I dare you. So I switched to square patches and discovered many advantages.
Square patches are even easier to subdivide.
Party on Wayne. Party on Garth. Converting square patches back into light maps is a lot simpler - you don't have to rasterize triangles or worry about floating point imprecision. Squares are much better area to approximate over than irregular triangles, so results would be more accurate. They don't look like crap.