Fully Momentum-Conserving Reduced Deformable Bodies with Collision, Contact, Articulation, and Skinning

Rahul Sheth, Wenlong Lu, Yue Yu, Ronald Fedkiw We propose a novel framework for simulating reduced deformable bodies that fully accounts for linear and angular momentum conservation even in the presence of collision, contact, articulation, and other desirable effects. This was motivated by the observation that the mere excitation of a single mode in a reduced degree […]

Efficient Simulation of Knitted Cloth using Persistent Contacts

Gabriel Cirio, Jorge Lopez-Moreno, Miguel Otaduy Knitted cloth is made of yarns that are stitched in regular patterns, and its macroscopic behavior is dictated by the contact interactions between such yarns. We propose an efficient representation of knitted cloth at the yarn level that treats yarn-yarn contacts as persistent, thereby avoiding expensive contact handling altogether. […]

High-Resolution Brittle Fracture Simulation with Boundary Elements

David Hahn, Chris Wojtan We present a method for simulating brittle fracture under the assumptions of quasi-static linear elastic fracture mechanics (LEFM). Using the boundary element method (BEM) and Lagrangian crack-fronts, we produce highly detailed fracture surfaces. The computational cost of the BEM is alleviated by using a low-resolution mesh and interpolating the resulting stress […]

Simulating Rigid Body Fracture with Surface Meshes

Yufeng Zhu, Robert Bridson, Chen Greif We present a new brittle fracture simulation method based on a boundary integral formulation of elasticity and recent explicit surface mesh evolution algorithms. Unlike prior physically-based simulations in graphics, this avoids the need for volumetric sampling and calculations, which aren’t reflected in the rendered output. We represent each quasi-rigid […]

Air Meshes for Robust Collision Handling

Matthias Mueller, Nuttapong Chentanez, Tae-Yong Kim, Miles Macklin We propose a new method for both collision detection and collision response geared towards handling complex deformable objects in close contact. Our method does not miss collision events between time steps and solves the challenging problem of untangling automatically and robustly. It is conceptually simple and straight […]

Subspace Condensation: Full Space Adaptivity for Subspace Deformations

Yun Teng, Mark Meyer, Tony DeRose, Theodore Kim Subspace deformable body simulations can be very fast, but can behave unrealistically when behaviors outside the prescribed subspace, such as novel external collisions, are encountered. We address this limitation by presenting a fast, flexible new method that allows full space computation to be activated in the neighborhood […]

Parallel Particles (P^2): A Parallel Position Based Approach for Fast and Stable Simulation of Granular Materials

Daniel Holz Granular materials exhibit a large number of diverse physical phenomena which makes their numerical simulation challenging. When set in motion they flow almost like a fluid, while they can present high shear strength when at rest. Those macroscopic effects result from the material’s microstructure: a particle skeleton with interlocking particles which stick to […]

Continuous Collision Detection Between Points and Signed Distance Fields

Hongyi Xu, Jernej Barbic We present an algorithm for fast continuous collision detection between points and signed distance fields. Such robust queries are often needed in computer animation, haptics and virtual reality applications, but have so far only been investigated for polygon (triangular) geometry representations. We demonstrate how to use an octree subdivision of the […]

Fast and Exact Continuous Collision Detection with Bernstein Sign Classification

Min Tang, Ruofeng Tong, Zhendong Wang, Dinesh Manocha We present fast algorithms to perform accurate CCD queries between triangulated models. Our formulation uses properties of the Bernstein basis and Bezier curves and reduces the problem to evaluating signs of polynomials. We present a geometrically exact CCD algorithm based on the exact geometric computation paradigm to […]

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 […]