During the course of game play objects interact by colliding. This can be by obscuring each other from view known as trace channels, sometimes referred to as a depth buffer else where. Another type of interaction is collision. Collisions happen when two objects come to be at the same location in space.
Unreal has three collisions statuses : Block, Overlap and Ignore. Blocking prevents two objects from being in the same location. Overlapping allows the objects to share the same space and emits a signal. Ignore also allows two objects to share the same location, but doesn’t emit the signal.
To reduce computational overhead, unreal allows game designers to use simplified proxies for geometry instead or full resolution models depending on the specific application.
