The Research Of Cloth Automatic Tearing Based On Mass-Spring Model

In the past few decades, computer animation is always the research field that researchers are interested in. Go along with the development of three-dimensional animation and virtual reality technology, and the exigent demands of the three-dimensional computer games and dress CAD, the real-time dynamic simulation of cloth, as an important part of the computer animation, attracts more and more researchers. Although there have been a lot of researches on dynamic simulation of cloth, the simulation of cloth automatic tearing is still a big challenge. In this paper, the main contents and achievements are as follows:Firstly, the paper describes the basic theory of the dynamic simulation of cloth. Cloth modeling is the basic of dynamic simulation. The paper discusses the strong points and shortcomings of the methods, which involve geometric methods, physical methods and mixed methods. Then we model cloth by mass-spring model, which is a physical method. Based on the analyses on the strong points and shortcomings of kinds of numerical integration methods, we chose the explicit euler method to solve the problem of integration.Secondly, this paper put forward an improved mass-spring model and simulates the automatic tearing of cloth. The paper analyzes the current method of cloth tearing and points out its flaws. Then the paper put forward the concept of "spring capacity" and gives out its formula. When the external force applied to cloth is greater than the "spring capacity", the cloth will be torn. The result of experimentation proves that the improved model has a good effect.Thirdly, this paper uses AABB bounding volume to deal with collision detection of cloth. We construct the binary AABB hierarchical bounding volume trees for cloth and other objects and then solve the problems of cloth collision detection and self collision detection. If collisions are detected, the tree of cloth shoud be updated from bottom to top.Lastly, this paper designs an experiment to simulate the automatic tearing of cloth. It always follows out the idea of OOP and carries out the modeling, analyzing forces, tearing judgment, numerical integration, collision detection. The result shows that the improved model has a good efficiency and effect. So the improved model is a good beginning of the next research.