An object oriented curve and surface framework

Abstract

Each year, thousands of custom CAD/CAM/CAE applications are being created to meet the needs of industry, education and research. To facilitate this process, programmers should have available to them high-level tools which are device-independent These enablers will allow for the rapid creation of highly portable software.

From this need, a curve and surface framework is created. This framework allows the engineer to create, manipulate, and analyze geometric entities. The design allows new curve and surface implementations to be fully integrated into the framework without requiring modifications to other entities within the framework. The framework utilizes the International Standards Organization (ISO) and American National Standard Institute (ANSI) 3-D graphics standard, PHIGS, and is thus device independent. Furthermore, the use of the IGES data exchange standard enables the transfer of data through files with an ISO/ANSI/ASME accepted format.

Five curve classes and two surface classes are implemented to demonstrate the potential of the framework. The curve classes include a Line, Polyline, Arc, Cubic Bézier, and NonUniform Cubic B-Spline Curve classes, and the surface classes include the Non-Uniform Cubic B-Spline Surface and the Planar Surface classes.

The result of the design is a highly extensible and maintainable framework for geometric modeling which reduces the work required by programmers in the creation and integration of geometric entities in complex software.