Optimization Integrator for Large Time Steps

Theodore F. Gast, Craig Schroeder Practical time steps in today’s state-of-the-art simulators typically rely on Newton’s method to solve large systems of nonlinear equations. In practice, this works well for small time steps but is unreliable at large time steps at or near the frame rate, particularly for difficult or stiff simulations. We show that […]

Efficient Denting and Bending of Rigid Bodies

Saket Patkar, Mridul Aanjaneya, Aric Bartle, Minjae Lee, Ronald Fedkiw We present a novel method for the efficient denting and bending of rigid bodies without the need for expensive finite element simulations. Denting is achieved by deforming the triangulated surface of the target body based on a dent map computed on-the-fly from the projectile body using a […]

Defending Continuous Collision Detection against Errors

Huamin Wang Numerical errors and rounding errors in continuous collision detection (CCD) can easily cause collision detection failures if they are not handled properly. A simple and effective approach is to use error tolerances, as shown in many existing CCD systems. Unfortunately, finding the optimal tolerance values is a difficult problem for users. Larger tolerance […]

Adaptive Nonlinearity for Collisions in Complex Rod Assemblies

Danny M. Kaufman, Rasmus Tamstorf, Breannan Smith, Jean-Marie Aubry, Eitan Grinspun We develop an algorithm for the efficient and stable simulation of large-scale elastic rod assemblies. We observe that the time-integration step is severely restricted by a strong nonlinearity in the response of stretching modes to transversal impact, the degree of this nonlinearity varying greatly […]

Adaptive Tetrahedral Meshes for Brittle Fracture Simulation

Dan Koschier, Sebastian Lipponer, Jan Bender We present a method for the adaptive simulation of brittle fracture of solid objects based on a novel reversible tetrahedral mesh refinement scheme. The refinement scheme preserves the quality of the input mesh to a large extent, it is solely based on topological operations, and does not alter the […]

Simulating Articulated Subspace Self-Contact

Yun Teng, Miguel Otaduy, Theodore Kim We present an efficient new subspace method for simulating the self-contact of articulated deformable bodies, such as characters. Self-contact is highly structured in this setting, as the limited space of possible articulations produces a predictable set of coherent collisions. Subspace methods can leverage this coherence, and have been used in the past to accelerate […]

Implicit Multibody Penalty-based Distributed Contact

Hongyi Xu, Yili Zhao, and Jernej Barbic The penalty method is a simple and popular approach to resolving contact in computer graphics and robotics. Penalty-based contact, however, suffers from stability problems due to the highly variable and unpredictable net stiffness, and this is particularly pronounced in simulations with time-varying distributed geometrically complex contact. We employ semi-implicit integration, […]

Automatic Construction of Coarse, High-Quality Tetrahedralizations that Enclose and Approximate Surfaces for Animation

David A. Stuart, Joshua A. Levine, Ben Jones, Adam Bargteil Embedding high-resolution surface geometry in coarse control meshes is a standard approach to achieving high-quality computer animation at low computational expense. In this paper we present an effective, automatic method for generating such control meshes. The resulting high-quality, tetrahedral meshes enclose and approximate an input […]

Object-Centric Parallel Rigid Body Simulation with Timewarp

John Koenig, Ioannis Karamouzas, Stephen J. Guy We present an object-centric formulation for parallel rigid body simulation that supports variable length integration time steps through rollbacks. We combine our object-centric simulation framework with a novel spatiotemporal data structure to reduce global synchronization and achieve interactive, real-time simulations which scale across many CPU cores. Additionally, we provide proofs that both our […]

A GPU-Based Streaming Algorithm for High Resolution Cloth Simulation

Min Tang, Ruofeng Tong, Rahul Narain, Chang Meng, Dinesh Manocha We present a GPU-based streaming algorithm to perform high-resolution and accurate cloth simulation. We map all the components of cloth simulation pipeline, including time integration, collision detection, collision response, and velocity updating to GPU-based kernels and data structures. Our algorithm perform intra-object and inter-object collisions, […]