THE SURVEY OF DECORATIVE ELEMENTS WITH LASER SCANNER

In presence of decorative apparati applied to architecture, traditional survey certainly sets some limits to the representation of the object itself. As regarding elements characterized by plastic forms, reproducing realistic subjects with phitomorphic, zoomorphic and human features or made up of complex geometrical forms, the canonical representative patterns don't allow a true restoration in quality and quantity of data, as they are founded on the traditional of Monge rules, which give back the real object, through the syntetic individuation of its forms. In support of these "lacks", today new computer methodologies are being discovered; infact, as they are rigorously based on traditional rules and codes of design and survey, they are able to achieve enthusiastic results, succeeding in acquiring complete formal and dimensional data. A survey, which could be considered "global", defines only the analyzed object, through the laser scanning (scanner 3D), an instrument which revolutionizes the principles of the relief and graphic restoration, as it supplies a digital pattern characterized by a rich code of topographic information (cloud of points), subsequently elaborated to realize a digital (mesh, texture), or mathematical pattern of the object in relief (Nurbs). This is an instrument, which replaces the conventional graphics with a digital model, characterized by a numerous code of topographic individuation, subsequently processed in CAD to realize a numerical or geometrical pattern of the object in relief. Besied, the possibility of shaping the photograph of the object in form and dimensions. Some examples of decorative elements belonging to different ages and keeping the memory alive about the ancient architecture of the town of Catania, have been chosen: traces of the Catalan domination, undamaged by the earthquake of 1693, which destroyed almost entirely the town, are represented in the balcony inside the Cortile Platamone, symbol of an architecture with geometrical elements in the traditional black-white chromatism, characterized by a linear plasticity. This plasticity reaches extraordinary examples in the Baroque architecture of Catania, as in the facade of Monastero dei Benedettini, which, with the rich decoration of capitals, frames, corbels and tympani, is a sublime example of mastery in the stone-work.