一种基于CityGML的三维模型单体化方法

实景三维中国建设应满足自然资源管理与社会经济发展需求，因此需要对基础地理信息产品进行实体化改造，三维模型单体化正是实体化改造的关键环节。本文提出了一种基于CityGML的三维模型单体化方法，首先根据地物实体轮廓的二维矢量面提供的顶点坐标及高程信息，构造墙面、屋顶等多边形平面组成地物的简单三维表达，然后配合渲染到纹理技术（RTT）进行纹理贴图，基于CityGML为每个二维矢量面对应的地物重构出有语义、有LOD层级的三维模型。该方法能够高效地实现三维模型单体化，且成果模型容量小，可满足各种实景三维应用需求。

A method of simplification of 3D model based on CityGML

3D real scene should meet the needs of managing natural resources, society and economics, which puts forward making basic geographic information products entitize. The simplification of 3D model is the key link of the transformation. Based on the experience of existing methods, this paper proposes a simplification method for 3D model based on CityGML. Based on two-dimensional vector of the solid profile of the figure vertex coordinates and elevation information, build polygons for walls, roof, etc. Combine the polygons into a simple three-dimensional expression. Then Texture map with Render to Texture technology (RTT), build 3D model for each two-dimensional vector by refactoring semantics and LOD levels based on CityGML. This method can successfully make 3D model entitize which occupies a small capacity, and meets various application demands of 3D real scene.