Abstract
This paper describes a method of obtaining a surface region of pentagonal and hexagonal shapes which appear around a concave-convex mixed vertex of a polyhedron which represents a basic feature of a surface. Features of the method are i) Final shapes are obtained from Bezier patches, and ii) Dispositions of control points are automatically defined by specific locations of the polyhedron. The element patch is degree two for the pentagonal region and degree three for the hexagonal. And a connecting condition of patches is C1. At first authors treat roundings and filletings for the pentagonal region around a vertex formed with convex and concave edges. Then five patches of degree two are obtained for such case. Secondly authors derive six patches of degree three for the hexagonal region to show an application of the method which requires higher degree patches. An example of such application is also shown.
