Comment by mfro
1 day ago
SSAO really is awful but it’s the best performing AO we could get for a long time afaik. It’s such a hallmark of 00s and 10s rendering that I laugh every time I see it in a modern release. There are some new solutions hitting the space, I believe RTGI/PT inherently handles AO, and there is even a new method called ‘FidelityFX CACAO’ which does look considerably more realistic. Things are improving… slowly.
AO is an approximation of how indirect light behaves. If you have an actual global illumination solution you don't need these tricks.
AO is derived from full GI with some extremely crude approximations. Anything that simulates full GI more accurately is implicitly a more physically accurate replacement of AO. Still, AO is not dead because it is still a rather simple and cheap cheat to add more visual definition to concave corners and highly shadowed areas. Sometimes, artists decide that their scene should have this extra touch.