The Munich Surveying Office can now display the buildings of the regional capital in the form of a digital three-dimensional model. Since June 2002 the city has been able to convert its official geo data and the latest property information directly into a 3D model at the touch of a button with the aid of its SICAD geo information system. Existing buildings and buildings that are still at the planning stage are presented with impressive realism. Because of its added value for users of geo information, the Munich 3D city model has already been used for live planning projects such as the “Isar South” development project.
The starting point for the 3D city model of Munich is the original data of the registry managed in the SICAD system and the data of the digital city map. Three-dimensional views and dynamic visualization are of such obvious benefit that the Munich Surveying Office has increasingly integrated the third dimension into the base data. The aim was to expand the area-based geo information system into a three-dimensional city information system. In addition to location-based and attribute information, the 3D city model includes the heights, shapes and architectural details of the buildings, giving a comprehensive and highly realistic impression of the city. The city of Munich therefore has a new tool for evaluating construction projects at a very early stage, for encouraging feedback from local groups and for presenting the projects to investors. The 3D city model is of enormous benefit not only to planning and approval departments in the Town Hall and to other such public authorities but also to architects, the property industry, public utilities and operators of mobile radio networks.
The block model already implemented in the first level of detail comprises the building floor plan, various attributes such as the height, and the type of use. In the second level of detail currently being implemented the roofs will be made even more realistic as three-dimensional surfaces. This expanded and improved block model ideally prepares the detailed information from the building database, which is often much more structured than the observer is aware. While a conventional CAD system would only be able to present the bare geometry, the Munich 3D city model links the original data itself by means of GIS. The system therefore enables more in-depth evaluations to be made and additional topics and data sources to be incorporated. At the push of a button the user can export the 3D data directly from SICAD in VRML format (Virtual Reality Markup Language), the standard exchange format for three-dimensional visualization and presentation on the internet. This simple and effective procedure, for which no software apart from SICAD is needed, is made possible by the characteristic openness of the system and its extensive options for entering data and structuring applications.
The 3D city model provides the dream option of taking virtual tours round the construction sites at the planning stage, offering a realistic impression of the buildings and their visual effect. Users can animate the three-dimensional display in VRML format by rotating, shifting and resizing it and can combine it with ortho-photos. This improves orientation within the model and provides expanded topographical information (vegetation, roads, etc.). To make the sections more realistic and improve their recognition factor, prominent buildings such as the Town Hall, churches and tourist attractions are being modeled in extra detail.