Turns off occlusion, making the tile never fade while tokens are under it.
Causes the whole tile to fade when an actor token moves under it.
Causes the tile to reveal the background in the vicinity of an actor token under it. The radius is determined by the token's size.
Causes the tile to be partially revealed based on the vision of the actor, which does not need to be under the tile to see what's beneath it.
Define the valid occlusion modes which an overhead tile can use
https://foundryvtt.com/article/tiles/