Study On Virtual Technology Of 3D Tree Morphostructural And Effect Under Wind Power

Virtual tree is of important use value in the fields of garden landscape design,community planning and city construction etc., if its morphological structure and the effect under wind power could be represented, there'll be lifelike and take on sense of reality. This paper studied on the key technology of virtual tree for the purpose of the real morphological structure and the sway of trunk,branches and leaves. The main content and inclusions are:(1) It improved the existing arithmetic of hierarchical and arboroid model, to the shortage that the model built is regular and orderly, it realized the randomness and reality by setting the parameters of branch and leaf model through the pseudo-random generate function and Gaussian random function.(2) To the shortage that the model built is static, it introduced the method that based on noise and simulated the natural wind using the fractal Brownian motion which is realized by random mid-point displacement with little calculate cost, and realized the real motion of trunk,branches and leaves in the wind.(3) For the stronger reality of virtual effect, it finished the rendering of 3D scene by introducing the techniques of texture mapping,fog simulation,background sound and lighting etc.(4) A new method which simplified the branch model was put forward. It applied vertex takeoff method, reduced the complexity of 3D tree scene and quickened the speed of rendering by constructing three different levels of details models.(5) For the higher efficiency of drawing, it ensured the bottleneck in the phase of CPU,geometric processing and rasterization through the empirical analysis, realized the flowline optimization with corresponding methods and ensured the real-time rending.(6) It developed the demo system of virtual tree morphostructural and effect under wind power and built the visual model of individual broadleaf tree by taking advantage of Visual C++ and OpenGL and introducing the method of modularization. The result shows that this system can perform the morphostructural character and realize the simulation of tree really.