Topological operators and Boolean operations for complex-based nonmanifold geometric models

Nonmanifold geometric modelling is used to represent and manipulate wireframe, surface and solid models in a single architecture. It is suitable for improving geometric-modelling environments for product design. The paper reviews some fundamentals of nonmanifold geometric modelling. A mathematical framework is introduced, and the topological structure and basic topological operations are discussed on the basis of the framework. Next, a new method, which can quickly and arbitrarily reshape geometric models defined by Boolean operations, is presented. This method is made possible by the capabilities of nonmanifold geometric modelling, and it can be used for interactive design by trial and error and form-feature modelling. © 1993.