Starting with a plane, and moving one of the verts inwards past the center point I have noticed seemingly strange behavior. 2 of the verts seem connected and always force a plane between them regardless of where the verts are positioned. (e.g. top left vert moved down and right - a triangle shape is forced between bottom left and top right verts)
The other 2 verts however are able to move freely and create the expected shape. (bottom left vert moved up and right)
The same thing happens with a cube when manipulated the same way (only on one of the 6 planes). Please can someone explain the reason for this?
Thanks