Constraint-Based And Feature-Based Cad Systems And Applications

A new generation of Computer Aided Design systems has become available in which geometric constraints can be defined to determine properties of large designs. The new design concept, often called constraint-based design or design by features offers users the capability of easily defining and modifying a design, but introduces the problem of solving complicated, not always well defined, constraint problems. Traditional parametric models can also be enhanced to partially support declarative constraint-based descriptions. We provide an overview of representation schemes for CAD applications. Then we present a survey of methods for geometric constraint solving appropriate for Computer Aided Design. We demonstrate how these representations and constraint solving methods can be combined or adapted to support a broad range of CAD applications by presenting two example cases of successfully using a feature-based constraint-based representation scheme to support two different CAD applications.