  We present a novel parallel algorithm for cloth simulation that exploits
multiple GPUs for fast computation and the handling of very high resolution
meshes. To accelerate implicit integration, we describe new parallel algorithms
for sparse matrix-vector multiplication (SpMV) and for dynamic matrix assembly
on a multi-GPU workstation. Our algorithms use a novel work queue generation
scheme for a fat-tree GPU interconnect topology. Furthermore, we present a
novel collision handling scheme that uses spatial hashing for discrete and
continuous collision detection along with a non-linear impact zone solver. Our
parallel schemes can distribute the computation and storage overhead among
multiple GPUs and enable us to perform almost interactive simulation on complex
cloth meshes, which can hardly be handled on a single GPU due to memory
limitations. We have evaluated the performance with two multi-GPU workstations
(with 4 and 8 GPUs, respectively) on cloth meshes with 0.5-1.65M triangles. Our
approach can reliably handle the collisions and generate vivid wrinkles and
folds at 2-5 fps, which is significantly faster than prior cloth simulation
systems. We observe almost linear speedups with respect to the number of GPUs.
