系统分析了现有的三维空间数据模型的形式和特点,为城市地下空间信息基础平台空间数据模型的选择提供了甄别的依据。针对城市地下空间信息三维建模和可视化分析的特点和要求,设计了面向空间结构信息和空间属性信息建模与可视化的三维空间数据模型。对于城市地下空间几何结构信息(包括三维地质体几何结构、地下构筑物和地下管线)的建模与可视化,设计了一种基于边界表示,面向地下空间实体并兼顾拓扑关系的三维矢量数据模型;对于地下空间属性信息的建模与可视化,采用三维栅格数据结构来组织表征地质体内部物理和化学属性参数的规则体数据;并根据地质属性建模与地质结构建模的关系和要求,实现了由三维矢量模型向三维栅格模型的转换。
Conceptions and characters of the existing 3D spatial data models were systematically analyzed and classified. To meet the special requirements of 3D modeling and visual analysis in urban underground spaces, two kinds of data models that suited to spatial structure information and spatial property information respectively, were designed and implemented. To express the complicated geometric structure of geological entities, underground structures and pipelines, a 3D vector data model, which is based on boundary-representations and topological relationships, was developed. 3D-raster structure model is used to modeling and visualization physical and chemical property parameters inside geological bodies. To meet the demand of the geological property modeling, a conversion approach of 3D vector data model to 3Draster structure model is implemented.