3D survey techniques for the conservation and the enhancement of a Venetian historical architecture

In recent years, thanks to a rapid and continuous technological development, the metric survey has had a significant increase in the digitization and enhancement of Cultural Heritage; in this research work, we will describe the methodology used to survey the ceiling of the Sala Capitolare of the Scuola Grande di San Rocco in Venice. On the occasion of the 500th anniversary of the birth of Tintoretto, the painter of the pictorial cycle on site, the Scuola Grande decided to increase the information regarding this historical architecture, carrying out an in-depth analysis of the ceiling structure. The complexity of this Venetian building, its considerable dimension, the richness of decorations and the particular lighting conditions have required the integration of different methodologies: the laser scanning survey and the photogrammetric acquisition, together with the topographic network, allowed to obtain an adequate metric result for the study of the structure in its entirety. Furthermore, we also decided to test the image acquisition with a spherical camera for the documentation and the enhancement of the analysed historical architecture. The geometrical complexity of the Scuola caused various problems during the survey campaign, resulting in some unconventional choices in the work phases: the research presented here analyses the difficulties encountered and it illustrates the solutions chosen in order to solve them and to study the ceiling of the Sala Capitolare.