Virtual Trackballs Revisited

Image of Trackball Demo Rotation of three dimensional objects by a two dimensional mouse is a typical task in computer aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. In our article, we review and provide a mathematical foundation for 3 popular virtual trackballs:
A self-contained source code implementing the above 3 virtual trackballs together with our own prefered trackball is available as C++ packed using Gzip and Tar: trackball.tgz. It is as part of the OpenTissue toolbox released under the GNU Lesser General Public License.

Please contact Knud Henriksen at for further details, comments, or suggestions.