Abstract: Road engineering Web3D archives management is important to improve decision-making ability. The key technologies including scene organization and management, integrated building and simplification method for road 3D model are studied. An organization and management method based on directed acyclic graph is proposed. Child nodes are derived gradually in depth by subdivision. Brother nodes are divided by mileage-section or sense type in breadth. Standard model nodes are shared by related father nodes. Based on constrained Delaunay triangulation, the road 3D integrated model is created. An error metric for 3D model simplification considering road constrained edges is put forward, in which, the geometric error for every edge and an additional error for constrained edge are included. The constrained edges can be refined preferentially. Benefit from above methods a road engineering Web3D archives management system is developed out, in which, road 3D model quickly view-dependent reconstruction is realized and constrained edges are retained on the client. This system has been applied to many highways construction and operating management.

Key words: road engineering, Web 3D, archives management；3D model simplification, error metric

摘要： 道路工程Web3D档案管理技术对辅助提高决策能力具有重要意义。对其中的海量数据组织管理、三维整体建模及模型简化方法进行了研究。提出了基于有向无环图的三维场景组织管理方法，深度方向从总体到细节的逐步细分，广度方向按里程分段或模型类型进行划分，标准模型节点为多个父节点所共享；基于约束Delaunay三角网建立了道路三维整体模型；提出了顾及约束的三维模型简化误差度量准则，考虑了对任意边进行简化时的几何误差，并为约束边建立了一个附加误差项，保证约束边尽早细化。基于上述方法开发了道路工程Web3D档案管理系统，远程客户端可快速重构出三维模型并较好地保留了约束边，目前已应用在多条高速公路的建设、运营管理中。

关键词: 道路工程, Web3D, 档案管理, 三维模型简化, 误差度量