INTERACTIVE GRAPHICS FOR VOLUME MODELING.

A description is given of the GRaphic INput subsystem (GRIN) of an experimental volume modeling system called the Geometric Design Processor (GDP). Sitting at an interactive graphic workstation, a mechanical designer generates computer volume models of complex physical objects and mechanisms built up from primitive volumes, e. g. , cuboids, cylinders, swept surfaces, etc. , entered at any orientation in 3-dimensional space. Objects are represented in the model as polyhedral approximations. The central issue is the provision of an efficient, natural means for a mechanical designer to enter and interact with these models.