虚拟场景中基于LOD的树木真实感建模

树是虚拟场景中的重要的景物之一。提出了用参数化的分形方法对三维树木进行真实绘制；将分形计算产生的树木数据用数据结构储存起来；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。实践证明，用文中方法在可漫游虚拟场景中产生三维树模型，在实时性与真实感方面均取得了不错的效果。

Realistic Modeling of 3D Tree Based on LOD in Virtual Scene

Trees are one of important scene in the virtual scenery landscape.The method of drawing 3D tree based on fractal and parameters is presented,all data calculated on fractal is stored in data structure,and picked up different model according to the distance from viewer to the tree is discussed in this paper.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.Experimental results show that the modeling of tree in roaming virtual scene acquires satisfied effects in real-time and third dimension.