(A) CAD system for interactive design and drafting of polyhedral parts

Abstract

This thesis presents an interactive design and drafting system for computeraided design of a class of polyhedral mechanical parts. Specifically, an interactive part design subsystem allows a designer to define and modify polyhedral objects, and design drafting subsystem to generate engineering drawings with standard dimensions specified interactivity. A design data-base is used to store the definitions of not only geometry but also drawings. Part geometry is described by means of a boundary representation and its validity is checked at the time of user input. A command language is designed in a device-independent manner through the use of BNF and implemented for keyboard interaction. The CAD system is written in FORTRAN and runs on CDC CYBER-174 with Tektronix 4010 series graphics terminal and Calcomp 960 plotter at the Software Development Center of KAIST.