基于粒子系统与OpenGL的实时雨雪模拟

自然景物的模拟一直是计算机图形学中最具挑战性的问题之一。关于水、云、烟．雨、雪等自然景物的模拟，在计算机游戏、三维动画、影视及广告中有着广泛的应用。自然景观中雨、雪的模拟，可以大大提高三维场景的逼真度，Reeves提出的粒子系统是模拟雨、雪的一种有效的方法。论文在分析粒子系统实现原理的基础上，基于OpenGL提出了一种在大型场景漫游系统中实时模拟雨．雪的方法。基本思想是基于OpenGL的多视口与色彩融合技术，把模拟雨、雪的粒子在一个新的视口中视线有效区域内进行绘制，然后与原视口中的场景一起显示于窗口中。实践证明，该方法实现的雨雪模拟效果比较真实，而且在普通PC上也可以满足一般动画的实时性要求。

Realtime Simulation of Rain and Snow Based on Particle System and OpenGL

Simulation of natural phenomena has always been one of the most challenging tasks in computer graphics. Simulating natural phenomena, such as water, cloud, smoke, rain, snow and so on, has been widely used in computer game, 3D animation, movie production and advertising, etc. Simulation of rain or snow in natural phenomena can greatly improve the fidelity of 3D scene, particle system presented by Reeves is a powerful way to simulate them. A method for simulating real-time rain or snow in a big scene is presented in this paper based on OpenGL after analyzing the realizing principle of particle system. The basic idea of the method is based on multi-viewport and color blending of OpenGL, it will render the particles of rain or snow within the eyesight in a new viewport, then shows them in the window together with the scene in the previous viewport. The results show that the method is effective and efficient, and they can even meet the requirements of real-time animation under generic PC.