Cloth Simulation Using Adaptive Multilevel Meshes And Collision Handling

Cloth simulation has wide application prospect, and it can be applied in many fields,such as virtual reality, video entertainment, games, three-dimensional garment design, andso on. It is a bottleneck for simulation to realistically simulate the movement of cloth andshow the wrinkles appeared on surface of cloth when it covers on a model. The efficiencyand effectiveness of cloth simulation relies on cloth modeling and collision detectionmethod, and we make discussion and research on the efficiency and effectiveness ofsimulation in this paper.Firstly, the cloth model made by Auto CAD software is read in, and the cloth isdiscretized to triangular grid by Delaunay triangulation method. We construct the modelbased on mass-spring, and analyze force of the mass by dynamics equation, then useVerlet method as a quick and easy way to solve the position and velocity of mess, andadopt texture mapping technology to reflect the rich texture details on cloth surface.Secondly, aiming at the draping process of cloth, the movement process is dividedinto several phases by adaptive multi-level grid technology. We use different density ofmesh to divide in the different phases, and there are less mass points in the prior phasethan the next phase which reduce the time of iteration. The optimized1-to-4refinementscheme is used to divide grid, and it can quickly achieve grid subdivision afterimprovement and optimization. Then the mass-spring model need to be reconstructed aftermesh refinement.Thirdly, we select the commonly used ellipsoid to approximate fitting for thecomplicated rigid model in the environment in order to avoid the complexity hierarchy ofbounding boxes. Ellipsoid bounding box can quickly eliminate impossible collision modelarea. We expand the ellipsoid and triangle patches of rigid model in some degree whichsimplifies the calculation of collision detection.Finally, we realize the cloth real-time simulation system under Windows platformswith C++language and open graphics interface OpenGL, and validate the proposedmethod by simulating cloth draping process and cover on a complex rigid model.