Posted on behalf of Daniele Mittica*, Michele Pellegrino**, Anita Rocco**
The creation of photorealistic 3D models of several objects, architecture, archaeological sites, artworks, or even entire landscapes, is increasingly becoming an established practice.
The use of 3D reconstruction tools are also important for an even more precise recording phase of the epigraphic finds; in fact if we are able to obtain a three-dimensional image, we can gain more accurate information about the technique or the instruments used for carving the inscriptions, or simply highlight all possible anomalies on the surface, which could be harder to notice at a first sight.
There are several advantages on using 3D models, such as choosing an appropriate point of view of the object (rotate, zoom in-out, even virtually taking measure), and the easy and convenient way to storage, duplicate and share the digital data.
A 3D model can be generated through different techniques or devices, such as laser scanner, Lidar, structured light applications, and photogrammetry, but it is not always simple to use all of them in every archaeological circumstance because of some reasons (limited financial resources, short time for field operations, logistic difficulties, lack of specific competences).
Nevertheless it is possible to obtain a 3D model starting from simple pictures, just using a compact or semi-professional digital camera and some photogrammetric technologies like the Structure from Motion (SfM), which is based on the dense stereo matching techniques: after shooting good quality photos, the entire data set it is processed within a specific dense reconstruction software which is able to generate a detailed and dense 3D point cloud that will be further elaborated for the solid geometry (meshing).
Our project, conducted on three different inscription testing three different applications such as an Open Source software (PPT – Python Photogrammetry Toolbox), a web-based solution (Autodesk 123D Catch), and a demo version of a commercial application (Agisoft Photoscan), has outlined the high potential of the Structure from Motion, which represents a positive alternative to the much more expensive and complex technologies like laser scanning.
3D models of the inscription of Damaris (wireframe – smooth – texture rendering).
3D models of the medieval inscription from the Cathedral of Bari (wireframe – smooth – texture rendering).
The availability of Open Source solutions or web-based software, the possibility to share and analyse the model using some powerful tools, such as PDF 3D or web-based viewer (3DHOP, Sketchfab), plus the widespread 3D printing, represent some of the possible developments connected to this technology, and an excellent way for improving the quality of the epigraphic documentation.
*Independent researcher – Italy
**Dip. di Scienze dell’Antichità e del Tardoantico, Università degli Studi di Bari “Aldo Moro” – Italy