Connectivity analysis: a tool for processing geometric constraints

Abstract

The use of geometric constraints allows computer-aided design systems to capture a designer's intent. This paper describes algorithms to process geometric constraints, including numerical relationships between dimension values. The proposed algorithms analyse the connectivity between constraints and the geometric entities which they constrain. One algorithm identifies parts of a geometric configuration that are subject to too many or too few constraints, and describes all possible options for correcting such potential problems. Another uses constraint priorities to select from those options. The final algorithm subdivides a large set of constraints into small subsets that can be resolved independently.