Example-Based Plastic Deformation of Rigid Bodies

Ben Jones, Nils Thuerey, Tamar Shinar, Adam W. Bargteil Physics-based animation is often used to animate scenes containing destruction of near-rigid, man-made materials. For these applications, the most important visual features are plastic deformation and fracture. Methods based on continuum mechanics model these materials as elastoplastic, and must perform expensive elasticity computations even though elastic […]

Fast approximations for boundary element based brittle fracture simulation

David Hahn, Chris Wojtan We present a boundary element based method for fast simulation of brittle fracture. By introducing simplifying assumptions that allow us to quickly estimate stress intensities and opening displacements during crack propagation, we build a fracture algorithm where the cost of each time step scales linearly with the length of the crack-front. […]

A Semi-Implicit Material Point Method for the Continuum Simulation of Granular Materials

Gilles Daviet, Florence Bertails-Descoubes We present a new continuum-based method for the realistic simulation of large-scale free-flowing granular materials. We derive a compact model for the rheology of the material, which accounts for the exact nonsmooth Drucker-Prager yield criterion combined with a varying volume fraction. Thanks to a semi-implicit timestepping scheme and a careful spatial […]

Pose-Space Subspace Dynamics

Hongyi Xu, Jernej Barbic 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 […]

Physics-Driven Pattern Adjustment for Direct 3D Garment Editing

Aric Bartle, Alla Sheffer, Vladimir G. Kim, Danny Kaufman, Nicholas Vining, Floraine Berthouzoz Designers frequently reuse existing designs as a starting point for creating new garments. In order to apply garment modifications, which the designer envisions in 3D, existing tools require meticulous manual editing of 2D patterns. These 2D edits need to account both for the envisioned geometric changes […]

Adaptive Skinning for Interactive Hair-Solid Simulation

Menglei Chai, Changxi Zheng and Kun Zhou Reduced hair models have proven successful for interactively simulating a full head of hair strands, building upon a fundamental assumption that only a small set of guide hairs are needed for explicit simulation, and the rest of the hair move coherently and thus can be interpolated using guide […]

Artist-Directed Dynamics for 2D Animation

Yunfei Bai, Danny M. Kaufman, C.Karen Liu, Jovan Popović Animation artists enjoy the benefits of simulation but do not want to be held back by its constraints. Artist-directed dynamics seeks to resolve this need with a unified method that combines simulation with classical keyframing techniques. The combination of these approaches improves upon both extremes: simulation […]

Surface-Only Liquids

Fang Da, David Hahn, Christopher Batty, Chris Wojtan, Eitan Grinspun We propose a novel surface-only technique for simulating incompressible, inviscid and uniform-density liquids with surface tension in three dimensions. The liquid surface is captured by a triangle mesh on which a Lagrangian velocity field is stored. Because advection of the velocity field may violate the […]

Drucker-Prager Elastoplasticity for Sand Animation

Gergely Klar, Theodore Gast, Andre Pradhana, Chuyuan Fu, Craig Schroeder, Chenfanfu Jiang, Joseph Teran We simulate sand dynamics using an elastoplastic, continuum assumption. We demonstrate that the Drucker-Prager plastic flow model combined with a Hencky-strain-based hyperelasticity accurately recreates a wide range of visual sand phenomena with moderate computational expense. We use the Material Point Method […]

Resolving Fluid Boundary Layers with Particle Strength Exchange and Weak Adaptivity

Xinxin Zhang, Minchen Li, Robert Bridson Most fluid scenarios in graphics have a high Reynolds number, where viscosity is dominated by inertial effects, thus most solvers drop viscosity altogether: numerical damping from coarse grids is generally stronger than physical viscosity while resembling it in character. However, viscosity remains crucial near solid boundaries, in the boundary […]