A blendshape model that incorporates physical interaction

We present a new technique for physically-plausible shape blending by interpolating the spring rest length parameters of a mass-spring system. This blendshape method begins by constructing two consistent mass-spring systems (i.e., with vertex-wise correspondence and the same topology) for source and target shapes, respectively, and setting the two systems as in their static states. In other words, their edge lengths equal to the rest lengths of the springs. To create an intermediate pose, we generate a new mass-spring system consistent with the source and target ones and set its rest lengths as linearly interpolated between source and target based on an interpolation factor α ε [0, 1]. The new pose is then synthesized by computing the equilibrium given the interpolated rest lengths. In addition, the mass-spring system may interact with other objects in the environment by incorporating collision detection.