When selecting something, the selected object is surrounded by a yellow box. The edges of the box are not occluded by the geometry that is selected, which breaks down the 3D perspective/illusion.

........................ ^ this vertical edge should be behind patella
The selection in the VTK view was pretty slick: the geometry changed color. Is there a reason for using a box to denote selection instead of changing color? I suppose I am fine with either mechanism.