Garment Simulation and Collision Detection on a Mobile Device

This paper describes several techniques for accelerating a virtual try-on garment simulation on a mobile device (smartphone or tablet) using parallel computing on a multicore CPU, GPU computing or both depending on the mobile hardware. The system exploits a mass-spring cloth model with velocity modification approach to overcome the super-elasticity. The simulation starts from flat garment pattern meshes positioned around a 3D human body, then seaming forces are applied on the edges of the panels until the garment is seamed and several cloth draping steps are performed in the end. The cloth-body collision detection and response algorithm is based on image-space interference tests and the cloth-cloth collision detection uses entirely GPU based approach on the newer hardware or recursive parallel algorithm on the CPU. As the results section shows the average time of dressing a virtual body with a garment on a modern smart phone supporting OpenGL ES2.0 is 2 seconds and on a tablet supporting OpenGL ES3.0 or 3.1 is less than one second.

A Wrinkled Membrane Model for Cloth Draping with Multigrid Acceleration

Fabric is modeled as a particular type of membrane formed from two orthogonal families of yarns. In contrast to usual membrane theory, the fabric is regarded to possess a certain compressive rigidity which is much weaker than its tensile rigidity. An energy density function is defined corresponding to the material model. The finite element formulation is based on the total Lagrangian approach. Four node quadrilateral elements are adopted. An accelerated multigrid technique using the conjugate gradient method as basic iterative method is employed to minimize energy to reach the final equilibrium position. Two examples of fabric draping are analyzed using the proposed model. The influence of the material parameters on the draping behavior is discussed.