Digital models for the virtual reconstruction and the representation of the existing: the city gates of Turin

This paper focuses on researches already undertaken and presented in this conference: starting from the work previously carried out for the setting up, at the urban scale, of a consistent database – which updates reading diagrams, maps, archival documents – for the fortified walls of the city of Turin, it intends to make thematic analysis aimed, on the one hand, to the survey of the "existing" and to a critically oriented reading of historical layers, on the other to the digital reconstruction. In this regard, for this work were particularly interesting the city gates, which constitute a homogeneous architectural 'category' divided into examples that follow the complex transformation, for successive enlargements, overlays, reconnections, of the layout of the walls. On the gates, we are organizing a collection of digital representations, uniformly designed and organized to test study approaches, operating methods, purposes, and modes of graphic communication: starting from the analysis and instrumental survey of the only well-preserved gate (Porta Palatina, I century AD) for the representation of the historical layers; to continue, in constant relation with sources, with virtual anastylosis.