三维动态云快速模拟的新方法

A New Method for Fast Simulation of 3D Clouds

自然景观真实感的模拟是计算机图形学领域中的研究热点和难点之一.尽管人们对静态云的真实感模拟进行了大量的研究,动态云模拟的工作还比较少.动态云的快速模拟技术在计算机游戏动画、飞行视景仿真、影视广告等许多领域具有重要的应用价值.提出了一种三维动态云快速模拟的新方法.首先,在较低分辨率的网格上求解云运动的物理方程,获得动态云的速度场.然后,采用纹理漂移的方法来增加云的表面细节.通过充分利用GPU的加速性能,该算法可以达到较高的绘制速度.最后,对上述算法进一步优化处理,使其可以适用于多种硬件平台.

The dynamic cloud simulation has been widely used in computer games, flight simulation, movie and TV advertisement, etc. Realistic simulation of cloud scene has been a research hotspot in the field of computer graphics. Although there are many previous works about simulation of static cloud scene, few attentions has been paid to simulation of dynamic cloud scene. The current methods of dynamic cloud simulation fall into two categories. One is heuristic methods and the other is physics based methods. The former can achieve fast rendering rates, but the results are less realistic. The latter can generate more realistic results. However, they need a large amount of computation. So a method which can take both rendering results and rendering rates into account is needed. The authors present a novel method for a fast simulation of 3D dynamic cloud scene. First, the velocity field of dynamic cloud is obtained by solving the physical equations of motion of dynamic cloud in a grid with relatively low resolution. Then, the texture advection is employed to add the details of the appearance of cloud. By fully accelerating with GPU （graphics processing units）, high rendering rates are achieved. Finally, the method is further optimized and can be applied in many types of hardware.