Handling of Positional Information in a System for Supporting Early Geometric Design

Abstract

A computer aided design (CAD) system for conceptual design should support not only functional and other relevant design activities, but also geometric information processing i.e. geometric design. At the early stages of geometric design, a designer’s attention and interest is mainly on exploring a variety of possible geometric configurations of a product, where geometric configuration refers to the total geometric structure of the product consisting of the approximate or precise geometry of components of the product and their overall spatial arrangement in forming the product [1]. Geometric configuration design is an iterative process of development - evaluation - refinement which leads to a suitable concept for further detail design. In this process, the designer handles various types of geometric information including shapes, sizes, locations as well as orientations of components which is known vaguely or precisely. Free-hand sketches and diagrams are frequently used during the process for effective expression, communication, and recording of both geometric and non-geometric aspects of or information about the product being designed [6, 7]. The roughness nature of such sketches and their use at early design stages reflects a desire to explore and investigate design options or concepts without committing to exactness or detail.