Decomposing Cloth

For nearly two decades, researchers have been seeking techniques that can efficiently and realistically simulate the motion of cloth. Believable animations are now expected in feature films. Games and virtual reality are next, but the computational costs are still high. We build upon certain popular cloth simulation techniques, improving their performance without sacrificing accuracy or generality. Click on the following images to see sample cloth simulation animations (cloth draping over a sphere and "waving arm", Quicktime animations.) Implicit schemes have become the standard for integrating the equations of motion in cloth simulation. These schemes, however, require the solution of a system representing the entire cloth mesh at each time step. Instead, we employ a technique that allows the mesh to be decomposed into multiple components which can then be solved more efficiently and in parallel. Our decomposition method depends on a number of techniques which improve the sparsity of the underlying system. These techniques include a novel adaptive implicit-explicit (IMEX) scheme which takes advantage of simulation parameters, locally in both space and time, to minimize the coupling of the system. Moreover, our adaptive IMEX scheme improves the efficiency of the computation in and of itself. Other sparsity improvements are obtained by exploiting the physical model of Choi and Ko (2002), as well as constraints in the system. Click on the following images to see visualizations of our decomposition technique as applied to the above animations. Particle colourings are used to identify the separated components at each time step. See the following Master's thesis for details: [ full pdf file ]