Integration of Solid Modeling and Data Base Management for CAD/CAM

摘要

For the fast growing CAD/CAM technologies, geometric solid modeling plays one of the most important roles. In order to satisfy a variety of engineering applications, an integrated database management system based on solid modeling is highly desirable. In the proposed approach, a concise object representation scheme, Constructive Solid Geometry (CSG), is adopted as the basis for database design. The underlying generic relational model is found to be more adequate than the conventional relational model in characterizing the embedded data abstraction. A systematic method is devised for converting the CSG scheme into a generic model based on the BNF grammar which depicts the CSG scheme. A relational query language, SEQUEL, has been modified to define, control, and manipulate the flat relations which represent the highly structural generic model.