多形态布料仿真中与刚体的实时碰撞检测

Real-time Collision Detection Between Variform Cloth in Simulation and Rigid Bodies

现实环境中布料存在多种形态并不可避免的与其他物体发生碰撞.为了丰富布料动画模拟的场景,采用不同硬度、不同分辨率、不同风速条件下的布料与物体发生碰撞,实时模拟多种条件下的布料动态场景,进一步提高布料动画模拟的实用性.首先,使用改进后的质点弹簧模型对布料进行建模,有效减少了虚拟弹簧的种类数,提高了计算速度和算法的稳定性.其次,提出一种简单风场模型描述真实风场,将布料受力均匀离散到各个质点上,简化了计算的复杂性;再次,使用改进的基元相交检测算法检测布料质点与碰撞物体三角面是否相交,有效避免了误判的产生;最后,根据布料与物体碰撞后会发生能量的耗散原理,修正碰撞后质点的位置和速度,有效解决了布料与物体的碰撞响应问题,大大增强了布料动画模拟的真实感.

In real environment, there are many forms of cloth and the cloth collides with other objects unavoidably. In order to enrich the scenes of the cloth animation simulation, we set the cloth of different hardness, different resolutions and different speeds of wind to collide with other objects, and then we get the real-time simulation of cloth in a variety of conditions, thus improving the effect of cloth animation simulation in reality. Firstly, using the improved mass-spring model to build the cloth model, this model reduces the number of virtual spring type effectively, and then the method improves the speed of calculation and the stability of algorithm. Secondly, the paper puts forward a simple model of wind field to describe the wind, the force of the cloth is scattered in the mass in average, simpli- fying the complexity of calculation. Thirdly, in order to avoid the possibility of mistake, we uses the improved algorithm of detecting atom intersect to detect whether the cloth masses associate with the objects. Lastly, according to the energy dissipation principle after the collision between the cloth and the objects,we classify the velocity and the position of the mass according to a certain extent,and finally we solved the collision response problem successfully and greatlv enhanced the reality sense of cloth animation simulation.