Le grottesche di Sant’Anna dei Lombardi, a Napoli. Analisi geometrica dell’apparato decorativo nello spazio architettonico

The needs to which the ornament responds do not have a technical-constructive character. Nevertheless, it constitutes a fundamental moment in the design and genesis of architecture, inseparably linked to the structure, making it unique. Cesare Brandi, in his Eliante, highlights the impossibility for architecture to be only functional without denying itself and reducing itself to a “passive constructiveness”. Centuries of architectural theory sediment negative values on the concept of ornament, to which Brandi instead attributes a founding value. The ornament can integrate and complete the basic structure, giving it artistic value. The case study of the sacristy painted by Vasari in the church of Sant’Anna dei Lombardi in Naples is emblematic. Between 1544 and 1545, the artist and historian carried out works in fresco on the cross vault, which became the reference point for the explosion of grotesque decoration in the Neapolitan city. The decorative apparatus constitutes the first completed and surviving attestation of this kind. The uniqueness of this decoration is considerable: behind the claim of antiquity, it manifests a stylistic principle opposite to that required by the Renaissance foundation of classical order: the power to dare. In Vasari’s renaissance hands, the quidilibet audendi potestas assumes an ordered form, which we intend to study here. The frescoes on the vaults illustrate a complex iconographic plan, rationally organized within regular geometric shapes, interspersed with 48 rooms in which the grotesque float. The subject of the investigation is the geometric-dimensional analysis of the decorative apparatus in relation to the physical-architectural space that houses it. For this purpose, digital photogrammetry is an essential tool for integrating and improving the visual investigation of frescoes. It provides digital models from which it is possible to obtain a correct graphic representation and a precise and accurate knowledge of the dimensional and qualitative characteristics. Processing on the photogrammetric model also allows for managing the geometric distortions relating to the curvilinear surface of the vault, allowing us to understand the exact relationship between the two-dimensional geometric element and the three-dimensional architectural conformation. Through the dimensional study, we intend to investigate and highlight how the ornament, ultimately, makes the space we live in unique and what is incomplete whole, adding what is necessary: meaning.