The Dynamic Simulation Of Realistic Trees Based On Ogre3D Engine

Tree is the most common plant in natural. It has many kinds of tree. The structure of treeis complex. The realistic tree modeling plays an important role in Virtual Reality. Withdeveloping of computer, the tree dynamic simulation can greatly improve realistic of naturalscene in Video Game, Garden Planning and Building Walkthrough System. In recent years,many domestic and overseas experts and scholars pay a lot of work to study the tree3Dmodeling and the tree dynamic simulation. And it have become a focus and difficult ofresearch in Virtual Natural Scene.In this paper, it finished the tree modeling and tree dynamic simulation in the wind fieldbased on the Garden Planning and Building Walkthrough System. Based on OGRE3D Engine,it finished the tree modeling and scene manger. And then, it finished tree dynamic simulationby Shader program. The system of tree dynamic simulation is more realistic and lesscalculation than other methods. It can show the structure of tree naturally, and the dynamicsimulation of tree has been simulated with vivid simulation effects. It uses GPU program toshare responsibility for CPU. And then it can improve the performance and efficiency of thiskind of systems.At first, this paper used Fractal Theory and base on Bezier curves to realize the trunk andbranch of tree rendering. The Cubic Bezier Curves with four control points has manyadvantages, such as the technique is mature; classical; less calculation; more control forcurves and easy to realize two curves matched. So it can simulate the bend, raised andrecessed of tree naturally. And then it used2.5D Impostor technology to realize the leafrendering. Compare with other Image based Rendering method, this method render leaf withdepth message. And then the leaf can show three-dimensional effect.About tree dynamic simulation, it used Array antenna beam pattern with white Gaussiannoise to simulate Gust Wind Field modeling. The control points of Bezier curves are theequivalent of mass points. The simulation of tree dynamic in wind field can be realized byanalyzing the force of control points of Bezier curves. It used CG program. It can increase therate of calculate, because of Parallel Computing of GPU.Finally, this paper gives the flowchart of tree dynamic simulation based on OGRE3D engineer and the results of simulation. And then we analyze the results, it can be found thatthe tree modeling more realistic and the tree dynamic more naturally. It is proved that themethod is tested and validated. And then it analyze that different scene have differentrequirements for tree modeling. It lays the foundation and provides the direction of futurework.