Surface Graph Sketching

Abstract

The production of patterns and designs upon surfaces has received only limited attention, with texturing techniques being accepted as adequate. Texturing, however, can be a very unsatisfactory and clumsy method of producing complex and accurate designs upon a surface, even more so with surfaces such as NURBS where a texture may appear very much distorted when mapped to a surface. This paper introduces a new approach called surface graph sketching which draws upon ideas from planar graph sketching for the construction of complex curve networks across parametrically defined surfaces. Surface curves can be created by a number of methods and stored in the parameter space of the surface thereby allowing intricate and more importantly accurate surface designs to be created. Regions of the surface may be assigned a property such as colour or texture, or cut away to produce holes. Surface graph sketching has a number of applications, in the design of trimming curves, surface patterning and texture map definitions.