Virtual 3D-City-and Architecture models, Virtual Globe systems like NASA World Wind and Google Earth as well as new attempts of immersive technologies become more important, not only among experts in spatial planning. These developments also reach out to the general social, cultural and everyday context. Given  the dynamic development of Google Earth, the discussion about the representation and the use of geodata for a wide user group beyond the planning disciplines reaches new heights. According to expert's opinion, Google Earth with his computer language KML (Keyhole Markup Language) becomes a 3D-Gis-Standard [Rush in 2006]. By the easy and quick representation of three-dimensional (city) structures and single buildings, Google Earth will significantly influence in all classes of society. User groups which have not been acquainted with geodata, highly specified and complex GIS-Systems [Dworschak in 2006], discover that working with these data by using Google Earth is great fun and they recognize, that with the help of the generally understandable visualisation of these data mediation of knowledge becomes very easy. In addition, it is acknowledged that geodata have an added value, if they will be used in disciplines such as the academic world, the financial sector or for private purposes.

Urban planning, city development and even landscape architecture are political spheres oriented to society in which analysis, planning, assessment and decision-making processes including the result of a planning cause a public interest [Luser&Lorber in 1997]. To many citizens, planning-theoretical expiries, the professional vocabulary and the abstraction of the third dimension into the planare second dimension are difficult to understand and not clear [Besser Schildwächter in 2000]. The essential advantage of a three-dimensional model is, may it be physically real or virtual, that the "model language" and consequently its contents can be made very clear [Streich 1996]. 

Many urban planning purpose and images of planning contents are still being discussed in planning committees with hand sketches or outline drawings, although there has been a progress of the CAD-representation and sketching in the third dimension. In times of Gameboys or XBoxes with their perfect graphic arts, all partners in the planning process may expect this comprehensive form of the representation. Regarding static planning sketches, they unambiguously lack a realistic view  in the virtual space, objects that are accessible multidimensionally and the playful acquaintance with planning variations. [Mitchell in 1999]. 

Spatial connections become visible in the 3D model, height developments are clearly readable and the viewpoints and look perspectives are freely eligible by a free navigation in the virtual model. A 3D-model serves, on the one hand, the spatially functional designing practise and on the other hand the better communication between those actors, who are involved in planning and execution process [Streich in 1996].
