基于L系统的树木模型参数化生成方法研究

Research on Construction of Tree Based on L-System and Parameterization

在构建虚拟场景时,树木是不可缺少的景物。传统的树木分形生成算法计算复杂、耗时长,不适于在构建实时动态的场景中使用。文中提出了一种在L系统分形算法基础上的树木模型参数化生成方法。该算法将树木模型先进行参数化处理,然后将分形计算产生的树木模型数据按层次储存起来,并根据视点与树模型的距离确定所需树木模型数据的层次,从而充分发挥了应用分形技术生成的树模型真实感强的优点,消除了分形计算耗时长的缺陷,保证了树木生成的真实性和实时性。对分形生成过程中遇到的随机数生成周期性及相似性问题给也给出了解决方法。

Construction of tree based on conventional fractal is a process which spends lots of time, so it isn＇ t suitable for structuring real time virtual scene. This paper presents a method for constructing tree in the nature. The method is based on L - system and separates tree into some parts, such as leaf, bole and so on. Then each part can be described as some parameters. All parameters calculated on fractal will be stored in the computer, and can be picked up according to the distance from viewer to the tree. This method gives full play to adequately exerts the characteristic that using fractal can generate realistic tree and avoid wasting time due to calculating in fractal. Also a solu tion to periodicity and comparability of random data generation, which always happen during fractal calculation, is given.