They almost get to this with some of their lighting demos -- the real joyous experience with this sort of lighting effect is to turn on a tiny bit of fog "dust" in some sort of big spacious building like a cathedral, and see the shafts of light coming in from various windows. Always a gorgeous effect to see in a video game.
Crepuscular rays are visible when you're facing away from the sun (hence their name, they generally exist when the sun is low). God rays are a fuzzier concept, but I've generally heard it when the rays appear to converge towards a light source (hence the divine term I guess). You could say both expressions do refer to the same rays, but with opposite perspectives.
