We enrich character animations with secondary soft-tissue Finite Element Method (FEM) dynamics computed under arbitrary rigged or skeletal motion. Our method optionally incorporates pose-space deformation (PSD). It runs at milliseconds per frame for complex characters, and fits directly into standard character animation pipelines. Our simulation method does not require any skin data capture; hence, it can be applied to humans, animals, and arbitrary (real-world or fictional) characters. In standard model reduction of three-dimensional nonlinear solid elastic models, one builds a reduced model around a single pose, typically the rest configuration. We demonstrate how to perform multi-model reduction of Finite Element Method (FEM) nonlinear elasticity, where separate reduced models are precomputed around a representative set of object poses, and then combined at runtime into a single fast dynamic system, using subspace interpolation. While time-varying reduction has been demonstrated before for offline applications, our method is fast and suitable for hard real-time applications in games and virtual reality. Our method supports self-contact, which we achieve by computing linear modes and derivatives under contact constraints.
Xu, H., & Barbič, J. (2016). Pose-space subspace dynamics. In ACM Transactions on Graphics (Vol. 35). Association for Computing Machinery. https://doi.org/10.1145/2897824.2925916