If you consider a player to be the origin, there is no way to test if a selection on an object (such as a door) is occluded by its host object. The intersect command does not match up with lineIntersectsSurfaces, nor does the intersect command always work with animated selections. For every LOD tested, some doors simply do not register completely with the intersect command. From my analysis, the only way to simulate occlusion for animated selections is by using probability, which means things that might work in most cases. I have a hard time accepting those solutions.