3D building modeling, organization and application in digital city system

The real world is a three-dimensional (3D) space requiring that 3D geospatial information applications be developed in alignment with the observer's visual and perceptive habits. Particularly, 3D building model data are required in a wide range of areas such as urban planning, environmental protection, real estate management and emergency response. At the same time, the development of Web service technologies allows the possibility of the widely distributed 3D geospatial data on the web. 3D city building model with its related information is an important part in the construction of a digital city system, and has become a staple resource on the web nowadays. In view of the hierarchical representation of a 3D building model, an abstract of a 3D building model based on structure details is studied, and a novel representation approach named 3D transparent building hierarchical model is presented in this paper. This approach fully uses both the existing 3D modeling technologies and CAD constructing mapping data. By the spatial relationship description, structural components inside a building can be represented and integrated as hierarchical models in a unified 3D space. In addition, based on the characteristics of the 3D building model data, a service-oriented architecture and Web service technologies for 3D city building models are discussed. The aim of the approach is that 3D city building models can be used as a kind of data resource service on the web, and can also exist independently in various different web applications.