3D model and ultraviolet fluorescence rendering: a methodological approach for the study of a wooden reliquary bust

Abstract

The focus of this paper is addressed to the ultraviolet fluorescence imaging diagnostics through an innovative application on 3D models and UV rendering. The approach is based on the acquisition of a set of images of an object in UV fluorescence by using the usual irradiation tubes and gelatine filters positioned in front of the digital camera lens. Specifically, in this paper the chosen object is a reliquary wooden bust representing Saint Rodonio, investigated during the restoration work.

The images, acquired through the digital camera, were used for creating, with the software AgisoftPhotoScan (R), the three-dimensional UV model of the reliquary bust. This technique allowed to map organic materials on the bust surface with the great advantage, in respect to a simple UV photography, of allowing the accurate localization of the different fluorescent areas in the three dimensional space. Photographic documentation and mapping of conservation status are among the most important phases in the conservation and restoration process. They constitute the basis for a correct planning of the interventions to be performed. In the case of three-dimensional objects, traditional photography could have some limits in mapping the overall surfaces of the artwork; these limits can be easily overcome through 3D documentation.