Deformable Objects Alive!

We present a method for controlling the motions of active deformable characters. As an underlying principle, we require that all motions be driven by internal deformations. We achieve this by dynamically adapting rest shapes in order to induce deformations that, together with environment interactions, result in purposeful and physically-plausible motions. Rest shape adaptation is a powerful concept and we show that by restricting shapes to suitable subspaces, it is possible to explicitly control the motion styles of deformable characters. Our formulation is general and can be combined with arbitrary elastic models and locomotion controllers. We demonstrate the efficiency of our method by animating curve, shell, and solid-based characters whose motion repertoires range from simple hopping to complex walking behaviors.