Interactive constraint system for solid modeling objects

The interaction of mechanisms applications presents a challenging domain for research in constraint-based systems. In these applications several requirements must be solved. Time consuming and complex tasks must t ake a dvantage of every computational opportunity to improve performance. Moreover, the c onstraints s olver must give a rapid solution even in critical situations s uch as under-constraints, over-constraints and cyclic constraints problems. In this paper, we present a geometric c onstraint system named LinkEdit t hat provides an interactive tool to construct objects from rigid p rimitives and constrain them by several constraints types. In LinkEdit system, internal and external constraints are integrated as a new paradigm for constraint definition and the constraint solver is designed to handle the previous requirements, by combining local propagation and p ropagation o f degrees of freedom techniques. Designers may want t o smoothly explore the domain they are designing by interactively making local modifications of the part. So, time c onsuming must t ake a dvantage of every computational opportunity to improve performance a nd the c onstraints s olver must dynamically maintain the constraints as the user modifies the design g iving rapid and un ique solution. Moreover, one of the most difficult tasks for a designer is to avoid breaking one part of a complex design while trying to fix or improve another. So, the constraints s olver must always give a solution even in critical situations such as over-constraint s or cyclic constrains problems. In this paper we present a geometric c onstraint system called LinkEdit that provides an interactive tool to construct objects from rigid p rimitives and constrain them by several constraints types. The c onstraints s olver is based on local propagation and propagation o f degrees of fr eedom techniques to efficiently maintain constraints organized in a c onstraint hierarchy. In LinkEdit system, internal and external constraints are introduced as a new paradigm to d efine the c omplete behavior f or an rigid object.