GIS Three-Dimensional Features to Recover City Centers

In the last years, a very rapid evolution of Geographic Information Systems (GISs) involved both implementation techniques and operative paradigms, in order to manage geographic information into digital databases. Particularly, GeoDatabases allow GIS users to intuitively manage very complex structures, such as technological networks, by exploiting the object-oriented representative model in order to describe geographic entities. This evolution makes possible the use of GISs by more and more people; on the other hand, users ask a more rapid evolution of GISs, in terms of technological tools (e.g. software, hardware, internet interfaces) as well as in terms of modeling availability. Loosely speaking, users require to represent situations and models which are hardly describable by actually on-sale general purpose GISs [BZ01]. Equipping GIS software with a 3D support can be a valid solution. In this case, 3D objects could be subjected to queries, without being only mere scenic representations. Aim of this work is the description of a suitable GIS plug-in, compatible with different GIS packages and implemented to extend functionalities of vectorial layers by the addition of a 3D component to existing spatial and alphanumeric ones. Surely, the 3D layer has been conceived in order to be queried as by a metric as by an alphanumeric point of view. Finally, according to GIS specifications, implemented plug-in is provided by data-entry utilities in order to change case-by-case the degree of representative details.