Abstract: Natural world is consisted of not only normal substances but also abnormal substances, which makes this world wonderful. Virtual reality shows solicitude for people more and more. At first, this article briefs the basic conception and grammar rule on Lindenmayer systems, which are regarded as the theory base with computer graphics and the tool of X3D to produce natural scenery and abnormal substances, such as trees,leaves, grass and flowers, which makes the virtual world much more authentic, by importing animation

Key words: Lindenmayer systems; Virtual reality; X3D; Animation

摘要： 自然界中不仅包含规则的物体，而且还包含不规则的物体，正是这些使得现实世界丰富多彩。虚拟现实技术越来越受到人们的关注。该文介绍了L-系统的概念及其文法规则，并以它为理论基础，结合计算机图形学，以X3D 为工具，生成虚拟的自然景物及不规则图形，如树木、叶子、花草等，并且通过引入动画机制来增强虚拟环境的真实感。

关键词: Lindenmayer 系统；虚拟现实；X3D；动画