I figured out a way to do unlimited light support for animated spinning planets in my game virtually for free.
Animation: Planets are spheres, so just scroll the U of the UV channel for the diffuse map.
Lights: Precompute an emissive map (including light colors), put it on a different UV channel.
Only potential problem is normal mapping won’t work unless I were to put the light angle in the emissive map, but planets are so far away it doesn’t matter.
Here’s a video
Emissive Scroll
There are NO lights and NO animation in that scene. I did that emissive map by hand but by rendering to texture it would look a lot better.
Diffuse map
Emissive map
