INTEGRATION OF SOLID MODELING AND DATABASE MANAGEMENT FOR CAD/CAM (QUERY LANGUAGE, GEOMETRIC DATABASE, FEATURE EXTRACTION)

Focusing on geometric completeness and data independence respectively, solid modeling and database management could be bridged together so as to provide a CAD/CAM environment with a unified geometric database for multiple application uses. The proposed approach is based on the CSG (Constructive Solid Geometry) scheme for solid modeling and the generic relational model for database management, primarily for the purpose of data conciseness while obeying a rigorous database design discipline. To facilitate data scheme definition, a systematic procedure has been devised to convert a set of grammar rules into a generic scheme. A relational query language, SEQUEL, has been modified to define, control, and manipulate the flat relations which represent the highly structural generic relational model. To further justify the usefulness of the proposed geometric database management system as well as its supporting query language, two application issues, namely, a solid modeler for CAD and a preprocessor for CAM, have also been investigated. The solid modeler that has been implemented not only acts as an application to be interfaced by the query language but also serves as a tool to visually verify the geometric data. Research efforts on CAM issues have also resulted in an algorithm capable of extracting and unifying certain manufacturing features that are embedded in CSG trees