I read online that omnidirectional lights don't typically cast shadows (this is true in, e.g., ARKit — https://developer.apple.com/documentation/scenekit/scnlight/1523816-castsshadow) — why is this? Is it for computational reasons (and if so, what are they, because none really come to mind compared to, e.g., a directional light) or physical reasons?
I read online that omnidirectional lights don't typically cast shadows (this is true in, e.g., ARKit — https://developer.apple.com/documentation/scenekit/scnlight/1523816-castsshadow) — why is this? Is it for computational reasons (and if so, what are they, because none really come to mind compared to, e.g., a directional light) or physical reasons?