What about some logic to hide the fact that the matrix has not been cleared? Is that too convoluted? Even just a better message when throwing the exception would help. But in this particular example, you select your ship from inside a hangar. The whole thing is already short of 400k triangles, so I need all the optimization I can get inside the hangar. The game itself, naturally, has a different orientation to the hangar (since the ships have to be positioned aesthetically relative to the player). Thus my little hack.