A Tool for the 3D Spatio-Temporal Structuring of Historic Building Reconstructions

The difficulty in the description, the analysis and the comprehension of cultural heritage often stands on the fact that buildings undergo numerous changes over time. Three factors condition the knowledge of historical heritage. Firstly, 3D reconstructions of heritage buildings focus normally on existing states and not on the management of historical evolutions. Secondly, if on one side iconographic sources are generally used like visual memory of a building temporal state to be restored graphically, on the other side few works today focus on the use of all metric and visual information contained in sources. At last, iconographic documentation concerning building past states is sometimes contradictory, dubious and incomplete. As a consequence, in 3D reconstructions uncertainties, contradictions and gaps in information should be highlighted. We present a methodological approach basing on the existing iconographic corpus for the analysis and the 3D management of building transformations. This approach joins three main aspects in a complete workflow. Firstly, it concerns the spatial and temporal referencing of 2D iconographic sources for the 3D reconstruction of disappeared building states. Secondly, it allows the analysis of building transformations by means of a temporal state distribution. Lastly, it uses spatial relations established between 2D iconography and 3D representation for the visual browsing of information based on spatiotemporal criteria. In particular, in this paper we detail the interface developed in order to accomplish multiple related tasks concerning the spatio-temporal structuring of the morphology to be reconstructed.