Interaction with constraints in 3D modeling

Abstract

The purpose of our research is to simplify and improve the effectiveness of the interactive definition of geometric objects in computer aided geometric modeling. To achieve this goal, two ways of defining geometric objects are combined and interfaced: 1) the definition of objects by graphical interaction and 2) the specification of objects by geometric constraints. To demonstrate the practicability of the proposed approach, a geometric modeling system was implemented. In this system, interactive modeling operations automatically generate constraints to maintain the properties intended by their invocation, and constraints, in turn, determine the degrees of freedom for further interactive mouse-controlled modeling operations. A symbolic geometric constraint solver is employed for solving systems of constraints. Group hierarchies are utilized for representing dependencies and for localizing systems of constraints.