Hi,
thanks very much for the Kirupa 3D tutorials. They are excellent. I am having one problem with the results, which is that the style of rotation is not consistant with what the user might expect. For instance, if you rotate horizontally (left) for 90 degrees, and then rotate vertically (down) the object will be turning the opposite way from what most people expect. This gets even worse when the interface is changed to “drag” the object’s nearest face to rotate. The movement of the nearest face does not match the direction of the mouse.
It seems the reason is that the mouse is just changing the object-relative axes, but sometimes (usually) screen axes no longer correspond to object axes.
I am sure transforming the mouse trig can solve this, but its been a long time since college 
Anyone already have this solved?
thanks!