Hi Ategig, thanks for the response.
Increasing the lightmap resolution results in slightly different splotches, but it does not make them go away.
I don’t get any warnings about overlapping UVs when I bake the lighting, but the meshes are just decimated versions of the rock sculpts, so there are a few long, narrow triangles that I worry are causing the problems. It’s also possible that it’s a problem of only having one light in the scene (the sun) and small overhangs in the rocks. Perhaps I am getting an accurate lightmap, and it’s just ugly.
The idea behind the baking is that the bounce lights eliminate the need for fill lights, right? Should I just be patient and wait until I have more rocks together, along with a floor? Will the bounce light then lighten up the shadows? Is there some other way to get softer, more natural shading?