Wu, JunDick, ChristianWestermann, RüdigerJan Bender and Kenny Erleben and Eric Galin2013-10-312013-10-312011978-3-905673-87-6https://doi.org/10.2312/PE/vriphys/vriphys11/029-038Recent work has demonstrated that composite finite-elements provide an effective means for physically based modeling of deformable bodies. In this paper we present a number of highly effective improvements of previous work to allow for a high-performance and high-quality simulation of boundary surfaces of deformable bodies with changing topology, for instance, due to cuts and incisions. Starting at a coarse resolution simulation grid, along a cut we perform an adaptive octree refinement of this grid down to a desired resolution and iteratively pull the fine level finite-element equations to the coarse level. In this way, the fine level dynamics can be approximated with a small number of degrees of freedom at the coarse level. By embedding the hierarchical adaptive composite finite-element scheme into a geometric multigrid solver, and by exploiting the fact that during cutting only a small number of cells are modified in each time step, high update rates can be achieved for high resolution surfaces at very good approximation quality. To construct a high quality surface that is accurately aligned with a cut, we employ the dual-contouring approach on the fine resolution level, and we instantly bind the constructed triangle mesh to the coarse grid via geometric constrains.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling Physics-based modeling I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism Animation