Semiautomatic three-dimensional interpretation of line drawings

Abstract The traditional method of describing shapes of technical objects in the form of views and sections is supported by most computer-aided design systems, allowing the designer to define drawings by means of an interactive graphics terminal and to store the corresponding descriptions in a suitable internal data structure. The purpose of three-dimensional interpretation of such two-dimensional oriented representations is to derive explicit descriptions of the three-dimensional shapes of the objects, as needed for a variety of computational processes. Automatic interpretation has been a topic of research at various places but has been successful so far only for very limited classes of shapes. In this paper, we pursue an approach based on interpretation under guidance of the user, assisted by an automatic process where safe algorithms are available for parts of the task. The concept presented addresses the class of shapes that can be described by constructive solid geometry including shaping operations.