A PRINCIPAL CURVATURE GRAPH FOR PRODUCT FORM ANALYSIS

In industrial design with a mechanical CAD system, since designers hav e a lot of hard time converting their images of a product form into a geometric model, it is necessary to help confirm the product form as a geometric model in some way. This paper describes techniques to analy ze free form surfaces and evaluate their features for confirmation by computer. First, recent surface evaluation methods are classified into three categories. Secondly, from one of these categories, a new curva ture visualization method using a principal curvature (PC) graph is pr oposed. The PC graph indicates surface features by analogy with primit ive surfaces such as cylinders, spheres or planes and has high sensiti vity in surface evaluation. Finally, results of tests on the PC graph developed as a prototype are shown and its effectiveness in industrial design is confirmed.