An Efficient Way of Fabric Simulation

A particle system model is presented for the simulation of fabric draping. The interaction of each particle is based on a refined mass-spring structure. Regarded the fabric material as an orthotropic continuum, the refinement of our model is focused on the construction of mechanical responses of bending and shearing springs by means of a piecewise polynomial approximation of KES-F testing data. In this way, the draping figure of a silk fabric, a wool fabric and a polyester fabric are simulated. The static final shape and animation of simulation proves that our model has developed an efficient technique on real fabric-drape modeling, and the little computation time of the simulation execution on a PC with Celeron 450 CPU may meet the requirement of real-time simulation.     

一种三维织物建模与仿真算法

织物三维变形形态的模拟一直是基于物理建模仿真研究的难点之一。针对织物非线性柔性变形的特点，利用粒子系统作为织物模型，结合OpenGL图形接口和Gouraud明暗处理，可以获得较为理想的具有真实感的织物悬垂仿真图表，适用于实时渲染的三维织物及服装CAD系统建模。     

Cloth Modeling Based on Particle System

A physical-based particle system is employed for cloth modeling supported by two basic algorithms, between which one is the construction of the internal and external forces acting on the particle system in terms of KES-F bending and shearing tests, and the other is the collision algorithm of which the collision detection is carried by means of bi-section of time step and the collision response is handled according to the empirical law for frictionless collision. With these algorithms, the geometric state of particles can be expressed as ordinary differential equations which is numerically solved by fourth order Runge-Kutta integration. Different draping figures of cotton fabric and wool fabric prove that such a particle system is suitable for 3D cloth modeling and simulation.     

高取向聚合物分子取向度与结晶度的各向异性

聚合物分子具有内部各向异性的物理特性,从而导致聚合物整体在大分子取向时呈现各向异性.为克服形态学超分子结构在评价这一特性时带来的误差,作者通过胶凝/结晶作用,制取超拉伸聚乙烯和聚丙烯薄膜,使之具有近乎完美的分子取向度及结晶度的形态,可以使得测量结果更为精确。利用广角X射线衍射(WAXD),直接测定了高取向聚乙烯和聚丙烯的结晶格子模量。在此基础上,测量并讨论了高取向聚合物结晶格子模量与杨氏模量、取向度、结晶度、温度之间的相互关系,以及在晶体色散研究中的一些现象与机理,从而澄清了聚乙烯与聚烯内部各向异性的几个特征。同时还研究了超拉伸聚乙烯的动态弹性模量、动态损耗模量和凝胶薄膜的力学性能。     

基于三维手绘线的服装设计

提出一种直接在三维人体模型表面绘制三维版型的方法.所绘制的服装版型通过一个基于该版型轮廓的碰撞表面形成三维服装表面,再由FFD(自由变形)方式对其形状进行调节,并通过基于Loop表面细分的全局曲率约束方法光滑形成服装曲面.通过该方法最终所得的服装曲面可用于紧身及舍身型服装原型设计.