Towards interactive 3D city models on the Web

Abstract
Virtual three-dimensional models of both cities and landscapes are becoming increasingly important for not only various business or public administration purposes, such as environmental simulations or facility management, but also for the broad public. Products like Google Earth brought virtual representations of the whole world to the fingertips of millions of users. Thereby, it became apparent that a 3D visualization is desirable and advantageous when representing geographic features. Furthermore, an ubiquitous accessibility of data over the Web is nowadays very common. Although the Web, 3D graphics and geographic data are crossing their ways, common applications are typically based on technologies that are rather esoteric to most web-developers. Nevertheless, in the last couple of months, some efforts towards a seamless integration of 3D graphics into common Web browsers have been performed. Regarding the data of such applications, they are mostly proprietary and commercial data, which are collected by professional cartographers or surveyors. Nevertheless, following the Web 2.0 approach, within the last five years the trend of Volunteered Geographic Information (VGI) became popular, describing an ever expanding range of users who voluntarily and collaboratively collects geographic data. Trying to merge the above mentioned trends and desires, a possibility for transforming the crowd-sourced OpenStreet- Map data into a 3D city model is described within this paper. Contrary to other existing approaches towards OpenStreet- Map 3D, the here presented approach combines emerging and established Web technologies, allowing an easy consumption in arbitrary web browsers. The applied technologies are easy to learn and understand by the web community and allow for quick prototyping, as well as creating mash-ups with further spatially enabled Web2.0 data.