Multilevel Cloth Simulation using

Figure 1: Cloth draped over a sphere. A coarse triangle mesh with 5100 vertices (left) is used for collision handling on the CPU while a high-resolution regular grid with 230k particles is simulated on the GPU to get fine wrinkles (middle). The right image shows a close-up view of the high-resolution mesh used for rendering. Today most cloth simulation systems use triangular mesh models. However, regular grids allow many optimiza-tions as connectivity is implicit, warp and weft directions of the cloth are aligned to grid edges and distances between particles are equal. In this paper we introduce a cloth simulation that combines both model types. All operations that are performed on the CPU use a low-resolution triangle mesh while GPU-based methods are performed efficiently on a high-resolution grid representation. Both models are coupled by a sampling operation which renders triangle vertex data into a texture and by a corresponding projection of texel data onto a mesh. The presented scheme is very flexible and allows individual components to be performed on different architectures, data representations and detail levels. The results are combined using shader programs which causes a negligible overhead. We have implemented CPU-based collision handling and a GPU-based hierarchical constraint solver to simulate systems with more than 230k particles in real-time