Regarding the video, you are right, when you mirror an object the pivot also transform. There's more to it than a mere graphical mirror ;) ie: a default box at [0,0,0] with default orientation has a matrix of: (matrix3 [1,0,0] [0,1,0] [0,0,1] [0,0,0]) Now if you flip/mirror the x axis and retrieve his transformation matrix…