Is it just a visual thing? Or does it affect gameplay?
Light influences how we perceive things. Those vampire encounters on a graveyard in BG2 were epic because they took place in the night. Comparable graveyard scene in D:OS2 was not memorable because it took place in the middle of the day or at least you would not have to time it and wait for the night.
I see what you mean and I agree with you on that. Lighting and effects can certainly enhance the mood and atmosphere. One way they could implement this feature would be through post-processing effects. I'm a huge Guild Wars fan and I grew up with that game and, because every map was its own instance, they didn't feel the need to implement a day/night cycle. Instead, they added these small post-processing effects throughout parts of the map, so that upon entering that area the sky would change to appear darker/brighter, red/green, etc., simulating the effects of day/night cycle or weather and enhancing the overall atmosphere. The feeling you got when all of a sudden the sky turned dark with clouds and in front of you appeared a skeleton necromancer was palpable.
It's not an expensive feature and I think this could work in BG3 as a workaround.
