It removes the culling performed on object details in mid to far distance for Ultra setting Draw Distance only. Also enemies use their best LOD possible in any setting.

Ultra should be Ultra and show everything possible, Occlusion Culling is still performed by the game and your graphics driver of course.

Culling is a technique to make things disappear, so they do not need to be rendered.

example video

Changes:
1.0.0.1 - Fixed exception if player is in menu/inventory, added check for Ultra setting Draw Distance.