Spherical Mechanism Design in a Virtual Environment



Spherical mechanisms are machines composed of links and joints that are designed to produce motion in three-dimensional space. These mechanisms are very difficult to design using traditional CAD tools because of the three-dimensional nature of the design space. A Virtual Reality environment, called SphereVR, was created that allows a user to specify the input parameters of the design while in a virtual space. This removes the restrictions of the two-dimensional computer interface and facilitates easy specification of the problem description. Once the input parameters are defined, the software synthesizes the mechanism and displays it on the constraint sphere. The user can then animate the mechanism to verify that the solution satisfied the design criteria. Once the mechanism is displayed, the user can move any of the pivots and the links are automatically resized. The software was written in C using Sense8’s WorldToolKit library on Silicon Graphics workstations. The visual VR peripherals that can be used with the software include an Eyegen3 head-mounted-display with a Flock of Birds magnetic position tracker or a Fakespace BOOM3C head-coupled display. The interaction device is a Logitech 3D mouse.

Additional Media


  • Osborn, Scott W. and Vance, Judy M., “A Virtual Reality Environment for Synthesizing Spherical Four-Bar Mechanisms”, Proceedings of the 1995 ASME Design Automation Conference, Boston, MA, September 11-14, 1995.



For more information, see: A Virtual Reality Environment for Spherical Mechanism Design