Transactions on Graphics (Proc. ACM SIGGRAPH 2015, to appear)

Simulating Rigid Body Fracture with Surface Meshes

Yufeng Zhu1     Robert Bridson1, 2     Chen Greif1

1University of British Columbia     2Autodesk, Inc

A boundary integral formulation of quasistatic elasticity, with Fast Multipole Method acceleration, drives a surface-mesh-only physical simulation of brittle fracture without volumetric dependencies.

Abstract

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 body by a closed triangle mesh of its boundary, on which we solve quasi-static linear elasticity via boundary integrals in response to boundary conditions and loads such as impact forces and gravity. A fracture condition based on maximum tensile stress is subsequently evaluated at mesh vertices, while crack initiation and propagation are formulated as an interface tracking procedure in material space. Existing explicit mesh tracking methods are modified to support evolving cracks directly in the triangle mesh representation, giving highly detailed fractures with sharp features, independent of any volumetric sampling (unlike tetrahedral mesh or level set approaches); the triangle mesh representation also allows simple integration into rigid body engines. We also give details on our well-conditioned integral equation treatment solved with a kernel-independent Fast Multipole Method for linear time summation. Various brittle fracture scenarios demonstrate the efficacy and robustness of our new method.

Key Words

dynamics, fracture, rigid body, boundary integrals, triangle mesh, Fast Multipole Method

Links

[Paper]     [Supplemental Report]     [Video]     [Code]     [BibTex]

Funding

NSERC (Natural Sciences and Engineering Research Council of Canada)

© Yufeng Zhu | Last updated: 05/14/2015