A multilevel approach to surface response in dynamically deformable models

Discretized representations of deformable objects, based upon simple dynamic point-mass systems, rely upon the propagation of forces between neighbouring elements to produce a global change in the shape of the surface. Attempting to make such a surface rigid produces stii equations that are costly to evaluate with any numerical stability. This paper introduces a new multilevel approach for controlling the response of a deformable object to external forces. The user speciies the amount of exibility or stiiness of the surface by controlling how the applied forces propagate through the levels of a multi-resolution representation of the object. A wide range of surface behaviour is possible, and rigid motion is attained without resort to special numerical methods. This technique is applied to the displacement constraints method of Gas-cuel and Gascuel 5] to provide explicit graduated control of the response of a deformable object to imposed forces.