I believe I already know the answer to this question, but I want to make sure I'm understanding this correctly. Within a physically based rendering pipeline, you calculate your indirect lighting from an hdri image (which is transformed into an irradiance map in engine (from what I can tell so far)).
Therefore if one had a scene which was outside for example and you were using some form of daytime sky hdri, but then you transitioned into a cave where there's very little or no light, you would then need a separate irradiance map for this location as well, correct?
Or if you wanted to emulate complete darkness, use a solid black irradiance map (or simply a shader that uses black for what would have been the calculated value of the irradiance map) and have your direct lighting (point lights, area lights, etc) be your only source of light?
Do I seem to be grasping the concept or am I missing something?