SOLID MODELLING : A MODULAR APPROACH TO COMPUTER AIDED DESIGN

Abstract

.Solid Modelling is a technique for computer aided design, in which construction of three dimensional objects is carried out by using well defined solid primitives. This is in contrast with wireframe, design technique, in which a object is represented by polygen .mesh. Since clid Modelling defines hov,, a object is created i.e. the discrete parts, of which the object is assembled, it is most suitable method for computer aided manufacture. Solid Modeilin can be implemented using different tech-niques. Till nc,., in most of the schemes a paure representation is used. n altoi'native hybrid approach, using; Constructive Solid Geometry . (CSC) and. Boundary Repr,_,scntation is proposed in this Thesis, L e terminal nodes of C $G tree j. e. primitives are constructed us 1 ~~,g boundary representation. The parameters o: ' primitives are evaluated, by projecting three dimensional space to four dimensional space. Using these parameters various geometric operations on primitives are carried out This Tiosie- has been successfully implemented on VAX W-780 c on putc:r taking polyhedra as representative solids.