Historical Documentation of Rock Churches in the “sassi” of Matera with Terrestrial Laser Data in a 3d Gis

With this study the Laser data acquisition and handling applied on a suggestive Italian Architectural Heritage was executed, in order to allow next complex spatial processing in 3D GIS visualization environments for the management and divulgation of information on Cultural Heritage. The site test is represented by the “Convicinio of S. Antonio” (XII-XIII centuries), that is one of the Churches carved into the rocks of the “Sassi”, the very ancient quarters of the Matera city. The Laser data of the above Churches were produced by means of the innovative technologies of the terrestrial Laser Scanner Leica HDS 3000, that it is able to extract in a fast way the third dimension of objects and makes high-definition field data capture easy and efficient. Particular attention was made on the potentiality of the CAD-GIS tandem using the feature type Multipatch with different softwares. The Multipatch permits to encapsulate complex objects in a compact way and to add also textures on surfaces, providing a real 3D objects visualization. Such technique is not still used because commercial GIS softwares have not specific tools to create 3D feature Multipatch. The 3D objects made with integrated procedures were next processed with GIS tools, verifying the effective possibility of executing three-dimensional thematic queries of complex georeferenced Laser data.