雨场下的树木建模方法分析

为了得到高效、准确、逼真的树木模型，研究了能够表达本身结构特性、形态复杂性以及受到自然环境中风雨雪等自然现象作用的树木建模方法.首先对树木建立静态模型;再在静态模型基础上，考虑自然环境中的风、雨、雪等客观真实存在且频繁发生的自然现象对树木的影响建立动态模型.并在建立风场中的树木动态模型方法的基础上，利用动量定理来计算对象在雨场中所受的冲力，且与对象杨氏模量中的断裂极限值相比较，确定对象断裂或者是摆动等情况，从而完善树木在自然界中的动态模型.经过实际建模比较，利用此种方法得到的树木动态模型时间损耗小，模型逼真.

Modeling Method for Tree in the Rainfall Area

It is difficult to find an efficient tree modeling method because of its own complexity and wind， rain acting on tree. A tree modeling method was constructed which could indicate the intrinsic structural characteristic， complex forms and the effects by the wind，rain， snow and other natural phenomena. Firstly， static model was constructed， based on which the dynamic model was established in which the effects on the tree by the wind， rain， snow and other natural phenomena were considered. The force was calculated by the momentum theorem based on the dynamic model in the wind. And then the value of rupture limit was compared to the Young’s modulus in order to determine the situation of fracture or sway. Thus， the tree dynamic model could be improved in the nature environment. During the modeling process， it was found that dynamic model with this method can reduce time decay and keep the modeling fidelity.