基于三层植物模型的大规模植物模拟方法

摘要

针对在大规模植物模拟中基于三维几何网格模型的植物模拟方法内存消耗大,以及基于二维平面模型的植物模拟方法近视点模糊缺陷问题,提出了一种基于三层植物模型的大规模植物模拟方法.该方法将大规模植物分为精度高的几何网格模型层、精度适中的impostor模型层和精度低的billboard模型层三层.根据植物到视点的距离,动态加载相应层中的模型,即当植物距视点较近时,加载精度高的几何网格模型层中的模型;当植物距视点较远时,加载精度适中的impostor模型层中的模型;当植物距视点很远时,加载精度低的billboard模型层中的模型.最后,利用Ogre图形引擎对三种植物模拟方法进行了渲染效果对比实验.由实验结果可知,该方法可以在低内存消耗情况下,取得与基于三维几何网格模型的植物模拟方法一样的逼真感,取得与基于二维平面模型的植物模拟方法相近的渲染速度.%Since the plant simulation method based on three-dimensional geometric grid model consumes a lot of memory and the plant simulation method based on two-dimensional plane model has a blur defect when it is near viewpoint in large scale plant simulation,this paper proposed a large scale plant simulation method based on three layers of plant model.This method divided the large scale plants into three layers:a geometric mesh model layer with high accuracy,an impostor model layer with moderate accuracy and a billboard model with lower accuracy.According to the distance between plant and viewpoint,the method automatically loaded the model in the corresponding layer.When the plant was closer to the viewpoint,it loaded the model in the model layer of the mesh model.When plant was far away from the viewpoint,it loaded the model in the model layer of the impostor model.When the plant was very far away from the viewpoint,it loaded the model in the model layer of the billboard model.Finally,it compared the rendering effects of the three kinds of plant simulation methods by using Ogre graphics engine.The experimental results show that the method can obtain the same realistic feeling as the plant simulation method based on three-dimensional geometric grid model,and the rendering speed is similar to that of the plant simulation method based on two-dimensional plane model in low memory consumption.