unless we specifically put a “box” there that says: calculate this all the time please.
I had that same idea but I came across one scenario where is might not be workable due to innate architecture of Lumen: Moving lights would invalidate the pre-calculated.
Funny enough jblackwell mentioned interpolated GI which could solve the pre-calculated profiles(time of day) of the world.
MGSV(2014) used ambient lights/probes(skylight blockers) for every hour of the day and every weather change. The ambient lights used 1/4th resolution cubemaps(not sure what was base resolution) of their static surrounding and then interpolated the those ambient lights as the time of day and weather changed.
I would say this worked visually and performance wise extremely well EXCEPT for a one kind of scenario. When any character would go beneath a strong light in a dark area, the model would not receive any lighting except from the strong light which resulted in the objects being almost pitch black in most areas which looked terrible.
With a “GI calculate box”. You could solve that by attaching that box to any dynamic or stationery/destructible such as the character to absorb proper bounce light.
This is what I mean by lack a per scene optimization tools if anyone was wondering about that when I first said it(I think Miguel1900 or Arkiras). More tools and ideas to save computing on areas where we don’t need computing.
Personally, I think we’re not getting these tools because UE targets FN. FN is a uncommon and worst case scenario because you can’t bake anything(because everything is destructible) meanwhile most open worlds(and successful ones) mostly consist of static objects like the environment.
But, hey I’ll throw out some ideas here.