3D Modeling and restoration: from metric to thematic survey. The case study of San Francesco al Prato in Perugia
Annotatsiya
A multisensor approach seems to be the most suitable solution for complex environment modeling. In this paper such an approach was \nexploited to generate a model, capable of covering different interesting aspects of the church of San Francesco al Prato, in Perugia (Italy). \nIt is one of the main churches of the city, reconstructed around the middle of XVIII century over a previous church, and enriched in the \ncenturies with masterpieces by such artists as Perugino or Raffaello. Unfortunately, due to some earthquakes its structure suffered several \nmajor lesions, as for example the loss of the roof, and the recent decision to restore it led to the need for an accurate survey.\nThe procedures adopted for documenting this building and some preliminary results are described here. Due to its interesting aspects, \nthe work was concentrated on the transept-apse complex, characterized by a complex spatiality, different building materials, a marked \narchitectural decay, and a geological instability of the underlying ground that produced cracks and lesion all over the structure.\nTopographic and digital photogrammetric tecniques have been employed in order to obtain complete and accurate data; 3D laser scanner \nhas been employed only on the transept. The model has been obtained from the merge of the different acquisition.\nThe documentation of such a complex architectural space was planned according to progressive levels of critical synthesis; the surveying \napproach described here followed the same logic and allowed us to obtain a three-dimensional model of the structure under investigation, \nby adapting the space resolution to the complexity of the surface or to the historical and artistic interest. Such tradeoff involved also the \noptimization of fundamental resources such as acquisition time or computer memory space, that have to be carefully taken into account \nin order to make any high complexity surveying project feasible.