基于L-系统的三维分形植物的算法及实现

分形理论适于解决不规则形态物体的建模仿真问题.分形理论和虚拟现实技术结合起来可以生成逼真、复杂的自然景物.该文将分形理论用于VRML 环境中研究植物的计算机模拟算法.首先介绍了常见的2维和3维分形植物生成算法,总结了它们的利弊.然后提出一种在VRML环境下改进的分形植物生成算法.通过描述树的属性（如树的种类、树的繁茂程度、树叶的形状等）,从而自动生成符合用户要求的三维树.最后给出了产生的3维分形树,并给出了一个应用实例.

Algorithm of 3D Fractal Plants Based on L-system and Its Implementation

The fractal theory is adapted to resolve the modeling and simulation of irregular-shaped objects.It can produce living and complicated nature scenery by combining the fractal theory with virtual reality technology.This paper uses the fractal theory into VRML environment for the study of plant's computer simulative algorithm.The paper firstly introduces the normal algorithms of 2D and 3D fractal plants,and analyses their advantages and disadvantages.Then it points out an improved algorithm of 3D fractal plants under VRML environment.By describing the property of a tree(such as the structure of the tree,the exuberance of the tree,the shape of the leaf and so on),computer can generate a 3D tree which meets the user's demand.At the end of this paper,examples of 3D fractal trees are generated.And a practical application is given.