Arcball like 3D figure rotation

One of the major drawbacks of matlab is the lack of a way of changing the viewpoint of a 3D mesh using a natural (arcball) interaction.

In this simple function I demonstrate the arcball interaction allowing a 3D sphere to be moved naturally. Run the function and drag and drop with your mouse on the sphere surface.

A very important aspect that you should note is that I am rotating the ACTUAL 3D object instead of the viewpoint.

There is a specific reason for this choice. The OpenGL lighting is linked to the axis in matlab, thus, if you rotate the veiwpoint, the lighting on the mesh surface wouldn't change. On the other hand, if you rotate your object using hgttransoforms you achieve this result.

It is now apparently bug-free :)