A modeling system based on dynamic constraints

We present "dynamic constraints," a physically-based technique for constraint-based control of computer graphics models. Using dynamic constraints, we build objects by specifying geometric constraints; the models assemble themselves as the elements move to satisfy the constraints. The individual elements are rigid bodies which act in accordance with the rules of physics, and can thus exhibit physically realistic behavior. To implement the constraints, a set of "constraint forces" is found, which causes the bodies to act in accordance with the constraints; finding these "constraint forces" is an inverse dynamics problem.