A third major research theme of Prof. Gross is concerned with the design of algorithms for physically based modeling. In the early and mid 90s, he started research on physically-based modeling for medical applications and computer games. He investigated FEM methods for the representation of soft tissue, for deformation, collision, fracture, fluids, and for other effects. His early work on full 3D finite element simulations of facial surgery was the first of its kind. Subsequently, he investigated realtime 3D soft tissue cutting algorithms. Such cutting is topologically, geometrically and physically very challenging and involves collision handling, simulation of deformation, friction, restructuring of geometry, topological consistency, and many other problems. His work with his students provides practical algorithms for soft tissue cutting. In addition, Gross has developed numerous algorithms for the physically-based animation of material effects such as fracturing, as well as stable, realtime deformations. Further of his research has been geared towards meshless simulation of physical effects. This work is closely related to point-based representations and avoids the costly computation of a FEM mesh for numerical simulations. Most recent results of Prof. Gross and his collaborators include efficient, high-quality fluid simulation algorithms for games and discontinuous Galerkin methods. Furthermore, he focuses on combinations of machine learning algorithms and numerical simulation to model complex physical phenomena in realtime. More information about this research can be found at graphics.ethz.ch/physics.