一种实现水波动画的新算法

近年来，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，关于山，水，云，烟，火焰等自然景物的模拟，在计算机游戏，影视，广告等各种领域中有着广泛的用途，作为自然景物模拟的重要内容，对流水，波浪的模拟正日益引起人们的关注，该文基于小振幅波理论和细胞自动机的模型，给出了一种实现水波动画的新算法，较之于以往的做法不同的是，作者既没有去特意构造具体的波形函数，也没有去求解复杂的Navier-Stokes方程，而是基于小振幅波理论和细胞自动机的模型，采用邻域传播的思想对水波进行动态的造型，在小振幅波理论中，水波的波形近似成正弦分布，根据这一规律，可以构造出不同邻域下水波演变的细胞自动机模型，文中还采用以POINT图元为基本粒子的粒子系统，对水花效果进行了实时的模拟，为了不波和浪花逼真地结合在一起，本文运用了色彩融和的技术来完成浪花的显示，实践证明用该算法模拟水波，效果比较真实，而且在普通的PC平台上即可满足一般动画的实时需求。

A New Algorithm for Water Wave Animation

In recent years, simulating natural phenomena has always been one of the most challenging tasks in computer graphics. Simulating natural phenomena, such as hills, water, cloud, smoke, fire and so on, has been widely used in computer game, movie production, and advertising, etc. As one of its most important parts, simulating water and waves has been given more and more attention. This paper presents a new method for water wave animation based on the theory of small amplitude wave and the technical model of cellular automata. Unlike traditional methods, we neither construct special functions to model the shape of water waves individually, nor solve the complex Navier Stokes equations. Instead, the idea of spread through neighboring regions is adopted to model the water waves dynamically. It is known that the shape of water wave is just like sinusoidal curves approximately due to the theory of small amplitude wave, so we can get the cellular automata model of water animation under different neighboring regions. A particle system is also used to simulate spoondrift in which point elements are taken as particles. The technique of color blending is used in the display of spoondrift in order to increase the visual reality of rendering results. Our results show that our models and methods are effective and efficient. They can even satisfy the requirements of real time animation under generic PC.