Ambient lights are lights from an infinitely far distance, e.g. sun lights. And since the distance of the source is too large, the length of the objective in the observable space is too small to make any difference in the intensitive of light, so we assume the ambient shading has a constant value.
neelkong
It is interesting that ambient shading is used sometimes instead of shadow rays to fill in black shadows. I wonder if this could be because using constant color instead of tracing shadow rays significantly saves computation time.
SmurphySean
Ambient occlusion is essentially fake shadows added on to the render by rays that are cast out from the surface. It helps soften the overall lighting in the scene if it's too bright
Ambient lights are lights from an infinitely far distance, e.g. sun lights. And since the distance of the source is too large, the length of the objective in the observable space is too small to make any difference in the intensitive of light, so we assume the ambient shading has a constant value.
It is interesting that ambient shading is used sometimes instead of shadow rays to fill in black shadows. I wonder if this could be because using constant color instead of tracing shadow rays significantly saves computation time.
Ambient occlusion is essentially fake shadows added on to the render by rays that are cast out from the surface. It helps soften the overall lighting in the scene if it's too bright