Canonical geometric modeling for computer aided design

Abstract

The objective of this paper is to describe a unified and flexible geometric model which is called a canonical geometric model. The canonical geometric model is composed of three models: (1)wire-frame model(2)area model(3)volume model These models are canonically represented in the form of a directed graph using a relational model and are accessed through a geometric model handler. They are applicable to various computer aided design systems and manipulated by an application program and by a designer at a graphic device. This canonical geometric model has been utilized in many application areas; topography, landscaping, and office building design.