Region-division Based Real-time Cloth Simulation

As the technology in computer graphics grows, the images produced by computers are getting more and more real. Some state-of-art rendering techniques simulates the world vividly and photo-realistic.Cloth simulating obtains a fast growth in recent years, meeting the needs of realistic character modelling in movie and gaming industry. Some cloth simulating methods successfully achieves photo-realistic rendering results. However, the cost of increasing computing time and resources is paid for realistic details. In many real-time interaction systems such as gaming, high efficiency is of great importance in the whole cloth simulation step. In these situations, real-time computing is the key in cloth simulation. Thus, another research interest in clothing simulating area is the balance of time efficiency and appearance details.This thesis proposed a region-division based real time method to simulate cloth. The method can add more wrinkle details with high computation efficiency. The main researches and contributions of the paper are as following:(1) Proposed a method to divide the cloth on human body into separate regions and take sampling in these regions. With this method, two problems are solved. Firstly, isolating the key regions that will accept special processing, we can deal with these regions later. Secondly, using the method of vertex cover with reasonable sampling in isolated area, the effects on the whole area of the sampling point can be remained as much as possible while reduce the number of the points which are involved in calculation. The final result can reach the effect that in the process of the whole cloth simulation process, we can use less particles that involved in calculating to reach the purpose of increasing wrinkle details.(2) Brought out a model to add winkle constraints among sampling points in joint regions. The basis of winkle constraints is the physical shape of wrinkles in real world, and winkle shape is simplified to build position constraint. By using this model, following problem is solved: simulating the cloth and adding more wrinkle detail in the joint regions. Throughout human motion, winkles are relatively dense in joints, and they vary along with joints angle changing. The model simulates winkle variation in cloth with human joints changing motion.(3) Designed and implemented a real-time cloth simulation framework. It leverages some key techniques of region division, constraints building, collision detection and numeric integration. The framework can simulate the cloth all by itself, it also can be called by other system and help them compute the position of all vertices. The framework strikes the balance between physical realism and computation efficiency. It reaches real-time efficiency in cloth simulation while adding more wrinkle details for the appearance.