So which bake mode should you use? Perhaps using indirect lighting and what other passes? Anyone have suggestions?
Lightmaps are generated in-engine, not in Cycles. For example, if you are using the Unreal engine or Unity, you’ll want to make a second set of UVs (atlas mapped). That UV will hold the information generated by the engine as a lightmap. The reason it’s done this way is to match the in game lighting and spherical harmonics that you are already doing in game. You’ll have to ‘generate lighting/lightmaps’ in the engine and then rebuild/compile to see the results. The map will be a simple black and white image that gets multiplied into the diffuse.
That is understood. However, some engines lack a good lighting system.
So while, yes it is certainly easier to baking lighting in engine, it is also possible to do so in an external program, as long as the assets/positions/basic material information stays consistent.
Perhaps I’ll work on it when it’s a more pressing matter and report back any positive findings.