3D GIS DATA MODEL USING OPEN SOURCE SOFTWARE

Today many kinds of applications requires data containing actual three-dimensional data; fields like urban and town planning and pollution studies need 3D data, both for visualization purpose, as well as carry out many spatial analysis. This research -Management and use of distributed 3D data by open source Web-GIS software - is part of the Italian "PRIN 2007"* research project, aimed to build urban and suburban 3D models, and to interact with them using open source software only. Particularly free and open source software, used for the experimentation here shown, are Blender and PostGIS; the first one has been used to build and structure three-dimensional data, the second one for data allocation. These software interact using scripts, written in Python language. Buildings have been modeled upon the GIANT3D model (Geographical Interoperable Advanced Numerical Topological 3-Dimensional Model) developed in the research "PRIN 2004", regarding "Evolved structure of numerical cartography for Gis and Web-GIS". Python scripts, activated by Blender, allow to allocate data into a spatial database implemented through PostgreSQL and PostGis, that could be a remote database somewhere on the net; all geometrical and topological information, implemented in the 3D model, are so transferred in PostGIS. These information can be retrieved by Blender using other Python scripts, so Blender fully interacts with 3D data allocated in PostGIS. These data can be also accessed by many other clients, both directly using a database client, as using other protocols (like HTTP on the internet). Next step is to build an open source viewer, or a plugin for internet browsers, that allows client to visualize, explore and inquiry 3D model, retrieving data from database.