Customizing Visualization in Three-Dimensional Urban GIS via Web-Based Interaction

This paper presents our research results of visualizing three-dimensional 3D city models in a web explorer environment under the supports of the digital building model, the digital terrain model, large-scale true urban orthoimage, and actual building sidewall pictures. A system has been designed and developed under a client/server architecture, which integrates the Internet Geographic Infor- mation System with multitier web applications for creation of a 3D city model. The front-end client provides a user interface for setting the properties of the 3D city model, and the back-end server processes these parameters and generates a 3D model, which is then sent back to the Virtual Reality Modeling Language-enabled World Wide Web browser for display and navigation. The technology for display and navigation of the 3D model is implemented using Java Server Pages/Servlet technology built under multitier web architecture. The technology for data accessing and processing is implemented through Java programming language. The displayer is linked to the database, where the required GIS spatial data are stored. The results from our experiments demonstrated that this developed system is able to display and visualize 3D city data in a web environment for public accesses. Using the sidewall pictures taken from real city buildings, we refill the white walls of urban buildings into a real appearance as seen in our real world cities. The player provides several click buttons to enhance the effect and position of visualization, including rotation, zoom, pan, seek, etc. The users can easily view the details of a specified building or/and the entire city in a moving 3D manner, and locate a specific building.