Reality-Based model and 3d information systems: a GIS 3D to mapping the crack panel of the Church of Santa Maria degli Angeli in Pizzofalcone in Naples.

The paper shows the approach used to analyze and document the conservation state of the Church of Santa Maria degli Angeli in Pizzofalcone in Naples. The Church was built between the 16th and 17th centuries and it was affected by events and alterations that changed its original structures. Although over the years it has been subjected to consolidation works, it currently has numerous cracks and it is affected by various deterioration pathologies that affect part of the wall and vaults, damaging the decorative elements too. The research activities focused on structuring of an operational process aimed to provide a mapping, in 3D GIS platforms, of the different phenomena found, in order to add attributes – not only descriptive ones – to the graphic visualization, which allow a typological cataloging and classification. The methodological process for the construction of the database is based on the acquisition of information to know the current state of the artefact through the consolidated technologies of survey no-contact and multi-sensor. The reality-based point clouds and mesh obtained from these operations have become the 3D references on which to identify the phenomena and relate the drawing and information. The models have therefore been the subject of indispensable integration and editing processes (cleaning, simplification, segmentation and classification) in order to adequately prepare the data for import and management in the 3D GIS workspace. The research is developed, therefore, in the field of experiments that intend to work on a conscious use of point cloud data and on the added metadata query according to logic that can be adapted to specific analyzes. Various theoretical and practical aspects were dealt, directing towards alternative uses of the various tools present in the software, so that application criticalities encountered were resolved from time to time. The results achieved so far are represented by the possibility of exploiting a 3D GIS database as a tool for deep knowledge of the mapped phenomenon for multilevel readings and diversified queries, in order to support decision-making processes and any maintenance interventions.