Forget all the camera rotation calculations. Just make a VERY WIDE range of adjustment for the user. If people think the camera is sluggish, they must have very slow computers. I have the rotation speed turned all the way to minimum and the camera rotates so fast I can hardly control it. 1/4 inch is more than180degrees of rotation, and I have the mouse acceleration set very low in Windows. This annoys me more than ANY other feature of the game. . . I’m constantly fighting with the mouse!