Abstract: This paper proposes a classified strain limiting method which deals with unreal stretch deformation in clothing simulation with physical-based mass-spring model. The method primarily include two processing module. The first module is classification. it uses velocity computed by integrating system as input parameters first, and then judges some point whether needs strain limiting by the energy method, finally through the judged result divides point set into two types : needing strain limiting and not. The second module is strain limiting. It defines the threshold value of spring deformation and three variables for representing the restrictive proportions in principal strain direction, and then by the line strain theory computes the strain tensor of spring, finally obtains specific restrictive proportions and updates the position of corresponding point. The method could guarantee natural simulation results and eliminate unreal stretch deformation, and does not require all elements of the strain limiting for processing, reducing the computational cost to ensure real-time. Results indicate that the method have good effect and efficiency.

Key words: clothing simulation, classified strain limiting, dynamics, mass-spring, collision detection

摘要： 针对服装仿真中基于物理的质点弹簧模型会产生不真实拉伸形变这一问题,提出了一种分类应变限制方法。该方法主要分为两大处理模块。第一个模块是分类：它使用积分系统计算的速度作为输入参数；然后通过能量法判断某个点是否进行应变限制；最后根据判断结果将点集分为需要应变限制和不需要应变限制两类。第二个模块是应变限制：首先，它设定了弹簧形变限制值和主应变方向上三个未知的限制比；然后根据线应变理论计算出与点相连的弹簧应变张量；最后，通过弹簧方向向量的不变性计算出限制比并更新点的空间位置。该方法在保证仿真结果自然的情况下避免了不真实拉伸形变，并且不需要对所有的图元进行应变限制的处理，减少了计算开销保证了实时性。实验结果表明该方法有不错的仿真效果和仿真效率。

关键词: 服装仿真, 分类应变限制, 动力学, 质点-弹簧, 碰撞检测