This is probably a really shitty and probably mostly incorrect analogy, but it sounds like you're describing Huygen's principle, which roughly says every point

This is probably a really shitty and probably mostly incorrect analogy, but it sounds like you're describing Huygen's principle, which roughly says every point light travels can be thought of as a very weak point source. For example, loads of old buildings have hallways with an open window, and rooms adjacent to the hall way would have "light-borrowing" windows. So light traversing down the hallway could still emit light in to the perpendicularly facing windows. There's some other stuff regarding light's wave/particle duality, so I don't know if there's a simple solution to whether it propagates in all of these paths, or as a particle moving in a straight line.