一种基于CityGML的三维模型单体化方法

A method of simplification of 3D model based on CityGML

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。

3 D 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 3 D model is the key link of the transformation.Based on the experience of existing methods,this paper proposes a simplification method for 3 D 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 3 D model for each two-dimensional vector by refactoring semantics and LOD levels based on CityGML.This method can successfully make 3 D model entitize which occupies a small capacity,and meets various application demands of 3 D real scene.