   mouse to object space
  Hi,I have a quad that can be rotated along all three axises, and am trying to figure out where in this quad the mouse lay. Without the x and y axis rotation I know I can unproject the mouses position to get the correct object space, however once I rotate around either the x or y axis this no longer works for me. So wondering how I can do this without resorting to ray casting. Also note I have tryed 'inverse(rotation) * mouse' but it doesnt work.edit: I figure what is happening with the inverse is that it is also affecting the z value and throwing off the x and y so this works correctly. However because im trying to negate any z transformations this just serves to throw off everything else.. so is there any way to ignore adjusting for the z?? (if that makes any since)   