An analytical method to determine the visible parts of parametrically defined tensor-product surfaces is described. All vistbility calculations are strictly oriented on the (u, u)-parameter plane. This leads to substantial advantages over visibility algorithms based on the approximation of curved surfaces by sets of planar polygons. The new algorithm allows… (More)
A CAD database will reach a consistent state only at the end of the design process. This paper provides a framework for transforming the CAD database into the final consistent state. "or this purpose we developed a model of a design object. Each design object can be composed of several representations. Some representations are independent of any other… (More)
Faster solutions to 3-D visibility problems and better distribution of multiprocessor systems can be achieved when this new connectivity data algorithm is used.
A personal-computer-based architecture that uses graphics methods to improve cooperative multimedia work over integrated services digital networks (ISDNs) is discussed. The system supports cooperative multimedia work by providing real-time video, graphics, and speech. The system requirements, components, and general architecture are considered, as is the… (More)