一种新的地物与地形的网格融合方法

Novel method of mesh fusion between 3D object and terrain

三维地形可视化中重要的地物模型需要使用CAD软件(3D Studio MAX/AutoCAD(3D)/MultiGen)构建的模型数据,来逼真表示城市的精细结构、材质特征及地物的内部形态,在将其和地形网格集成的过程中,必须让地物和地形之间实现无缝融合。提出了一种新的地物和地形的融合方法:首先读取地形高度图,利用基于四叉树的LOD技术生成地形网格,其次导入三维地物模型并放置于地形网格某位置,对三维地物模型投影得到地物模型的底面网格边界框及点集,地物边界框对应的地形网格分裂,产生融合位置的地形网格边界及对应点集,根据地物网格边界和地形网格边界的这两个点集以及Delauney三角形限定条件生成三角网,实现网格融合。利用该方法实现了四叉树LOD技术生成的地形和地物的融合,最后讨论了该方法的特点及应用。

Important 3D object models often used the model data which is created by CAD softwares（3D Studio MAX/AutoCAD（3D）/MultiGen） in 3D terrain visualization.These data are widely available in fine structure,material feature and inner shape.It should be matched perfectly in the process of integration between the 3D object model grid and terrain grid.In this paper,a novel method of mesh fusion between 3D object model and terrain grid is put forward.Terrain grid is generated by reading the terrain height map data.3D object model data is read into terrain grid and layed in an appropriate position.Then we could get a boundary and point aggregate by projection of 3D object,after dividing of the terrain grid of the boundary,the another boundary and another point aggregate are found.The Delauney triangle grid is generated by above two point aggregates and the Delauney condition.At last,the mesh fusion was realized.The method was demonstrated through grid fusion between terrain grid built by quadtree-lod technology and 3D object model grid.In the end of essay,the advantages and purpose of method are discussed.