Meshless animation of fracturing solids

Figure 1: Brittle fracture of a hollow stone sculpture. Forces acting on the interior create stresses that cause the model to fracture and explode. We present a new meshless animation framework for elastic and plastic materials that fracture. Central to our method is a highly dy-namic surface and volume sampling method that supports arbitrary crack initiation, propagation, and termination, while avoiding many of the stability problems of traditional mesh-based techniques. We explicitly model advancing crack fronts and associated fracture sur-faces embedded in the simulation volume. When cutting through the material, crack fronts directly affect the coupling between sim-ulation nodes, requiring a dynamic adaptation of the nodal shape functions. We show how local visibility tests and dynamic caching lead to an efcient implementation of these effects based on point collocation. Complex fracture patterns of interacting and branch-ing cracks are handled using a small set of topological operations for splitting, merging, and terminating crack fronts. This allows continuous propagation of cracks with highly detailed fracture sur-faces, independent of the spatial resolution of the simulation nodes, and provides effective mechanisms for controlling fracture paths. We demonstrate our method for a wide range of materials, from stiff elastic to highly plastic objects that exhibit brittle and/or duc-tile fracture