虚拟树木风中运动可视化模拟

根据树木在风中运动仿真的思路和方法,引入随机因子的过程函数模拟风场脉动特性;采用悬臂梁作为树枝材料力学分析的基本物理单元,并根据风工程理论和梁单元理论计算枝段在风力下的变形;采用力传递和运动合成求解整棵树木的枝干在风中的运动。最后设计了风对树木影响模拟软件功能模块,并将其集成于参数化单树建模原型系统。以毛竹为例,模拟了在不同风速条件下不同弹性模量的树木在风中形态变形,仿真结果从视觉效果上符合现实情况。

Visual Simulating Virtual Tree Movement in Wind

In order to better understand the wind affects the tree architecture deformation intuitively, an efficient modeling strategy of virtual tree swaying in wind was proposed based on the analysis of the existing thought and methods to simulate the tree movement in wind. The method used procedure function with stochastic factor to simulate the wind field; and the cantilever beam was used to simulate a segment of a stem as the mechanical analysis unit, the deformation of the beam in wind force based on the theory of wind projection and beam element was computed. Then the force transmission and movement compounding method was used to solve the whole tree movement in wind. Furthermore, some software function modules, which integrated with the parametric tree modeling prototype system, were developed. Taking Phyllostachys pubescens as an example, the tree swaying was simulated in different wind velocities and with different modulus of elasticity. The result is in accordance with the practical visual effects.