Interactive Two-Way Shape Design of Elastic Bodies

Rajaditya Mukherjee, Longhua Wu, Huamin Wang We present a novel system for interactive elastic shape design in both forward and inverse fashions. Using this system, the user can choose to edit the rest shape or the quasistatic shape of an elastic solid, and obtain the other shape that matches under the quasistatic equilibrium condition at […]

Learning Nonlinear Soft-Tissue Dynamics for Interactive Avatars

Dan Casas, Miguel Otaduy We present a novel method to enrich existing vertex-based human body models by adding soft-tissue dynamics. Our model learns to predict per-vertex 3D offsets, referred to as dynamic blendshapes, that reproduce nonlinear mesh deformation effects as a function of pose information. This enables the synthesis of realistic 3D mesh animations, including […]

A Material Point Method for Thin Shells with Frictional Contact

Qi Guo, Xuchen Han, Chuyuan Fu, Theodore Gast, Rasmus Tamstorf, Joseph Teran We present a novel method for simulation of thin shells with frictional contact using a combination of the Material Point Method (MPM) and subdivision finite elements. The shell kinematics are assumed to follow a continuum shell model which is decomposed into a Kirchhoff-Love […]

Eulerian-on-Lagrangian Cloth Simulation

Nicholas J. Weidner, Kyle Piddington, David I. W. Levin, Shinjiro Sueda We resolve the long-standing problem of simulating the contact-mediated interaction of cloth and sharp geometric features by introducing an Eulerian-on-Lagrangian (EOL) approach to cloth simulation. Unlike traditional Lagrangian approaches to cloth simulation, our EOL approach permits bending exactly at and sliding over sharp edges, […]

A Moving Least Squares Material Point Method with Displacement Discontinuity and Two-Way Rigid Body Coupling

Yuanming Hu, Yu Fang, Ziheng Ge, Ziyin Qu, Yixin Zhu, Andre Pradhana, Chenfanfu Jiang In this paper, we introduce the Moving Least Squares Material Point Method (MLS-MPM). MLS-MPM naturally leads to the formulation of Affine Particle-In-Cell (APIC) [Jiang et al. 2015] and Polynomial Particle-In-Cell [Fu et al. 2017] in a way that is consistent with […]

Animating Fluid Sediment Mixture in Particle-Laden Flows

Ming Gao, Andre Pradhana-Tampubolon, Xuchen Han, Qi Guo, Grant Kot, Eftychios Sifakis, Chenfanfu Jiang In this paper, we present a mixed explicit and semi-implicit Material Point Method for simulating particle-laden flows. We develop a Multigrid Preconditioned fluid solver for the Locally Averaged Navier-Stokes equation. This is discretized purely on a semi-staggered standard MPM grid. Sedimentation […]

An Implicit SPH Formulation for Incompressible Linearly Elastic Solids

Andreas Peer, Christoph Gissler, Stefan Band, Matthias Teschner We propose a novel SPH formulation for deformable solids. Key aspects of our method are implicit elastic forces and an adapted SPH formulation for the deformation gradient that—in contrast to previous work—allows a rotation extraction directly from the SPH deformation gradient. The proposed implicit concept is entirely […]

A Skinned Tetrahedral Mesh for Hair Animation and Hair-Water Interaction

Minjae Lee, David Hyde, Michael Bao, Ronald Fedkiw We propose a novel framework for hair animation as well as hair-water interaction that supports millions of hairs. First, we develop a hair animation framework that embeds hair into a tetrahedralized volume mesh that we kinematically skin to deform and follow the exterior of an animated character. […]

Exponential Rosenbrock-Euler Integrators for Elastodynamic Simulation

Yu Ju Chen, Uri M. Ascher, Dinesh K. Pai High quality simulations of the dynamics of soft flexible objects can be rather costly, because the assembly of internal forces through an often nonlinear stiffness at each time step is expensive. Many standard implicit integrators introduce significant, time-step dependent artificial damping. Here we propose and demonstrate […]

Stabilizing Integrators for Real-Time Physics

Dimitar Dinev, Tiantian Liu, Ladislav Kavan We present a new time integration method featuring excellent stability and energy conservation properties, making it particularly suitable for real-time physics. The commonly used backward Euler method is stable but introduces artificial damping. Methods such as implicit midpoint do not suffer from artificial damping but are unstable in many […]