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 surface mesh, avoiding extrapolation artifacts and ensuring that the resulting coarse volumetric meshes are adequate collision proxies. Our approach comprises three steps: we begin with a tetrahedral mesh built from the body-centered cubic lattice that tessellates the bounding box of the input surface; we then perform a sculpting phase that carefully removes elements from the lattice; and finally a variational vertex adjustment phase iteratively adjusts vertex positions to more closely approximate the surface geometry. Our approach provides explicit trade-offs between mesh quality, resolution, and surface approximation. Our experiments demonstrate the technique can be used to build high-quality meshes appropriate for simulations within games.

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

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 proposed data structure and our object-centric formulation are deadlock-free. We implement our approach with the functional programming language Erlang, and test the performance and scalability of our method over several scenarios consisting of hundreds of interacting objects.

Object-Centric Parallel Rigid Body Simulation with Timewarp

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, handles contacts and friction, and is able to accurately simulate folds and wrinkles. We describe the streaming pipeline and address many issues in terms of obtaining high throughput on many-core GPUs. In practice, our algorithm can perform high-fidelity simulation on a cloth mesh with 2M triangles using 3GB of GPU memory. We highlight the parallel performance of our algorithm on three different generations of GPUs. On a high-end NVIDIA Tesla K20c, we observe up to two orders of magnitude performance improvement as compared to a single-threaded CPU-based algorithm, and about one order of magnitude improvement over a 16-core CPU-based parallel implementation.

A GPU-Based Streaming Algorithm for High Resolution Cloth Simulation

Implicit Integration for Particle-based Simulation of Elasto-plastic Solids

Yahan Zhou, Zhaoliang Lun, Evangelos Kalogerakis, Rui Wang

We present a novel particle-based method for stable simulation of elasto-plastic materials. The main contribution of our method is an implicit numerical integrator, using a physically-based model, for computing particles that undergo both elastic and plastic deformations. The main advantage of our implicit integrator is that it allows the use of large time steps while still preserving stable and physically plausible simulation results. As a key component of our algorithm, at each time step we compute the particle positions and velocities based on a sparse linear system, which we solve efficiently on the graphics hardware. Compared to existing techniques, our method allows for a much wider range of stiffness and plasticity settings. In addition, our method can significantly reduce the computation cost for certain range of material types. We demonstrate fast and stable simulations for a variety of elasto-plastic materials, ranging from highly stiff elastic materials to highly plastic ones.

Implicit Integration for Particle-based Simulation of Elasto-plastic Solids