Ancient remains from the Roman Istanbul: a transmutation from stone to digital

Fragments, ruined architectures, parts of statues, all these elements have always exercised a strong fascination on humanity, evoking a close or far past and pushing the mind to imagine the piece original aspect and its surroundings, while creating a subtle melancholy which undoubtedly has a strong appeal on many people. At the same time, it is quite common to find the "puzzle" of ancient portions of monuments immersed in their same mystery, where they truly come from: which was their original asset? which series of events have caused such a destruction (and sometimes reconstruction)? Finding some correct answers is something quite difficult, because to read and to interpreter such elements is not easy at all. At the same time these artefacts are often at risk of rapid decay (being broken and damaged or exposed in the natural environment or not located according to their original destination), so they may deserve a proper documentation to preserve at least a (digital) copy. At the same time, their great suggestive potential may be a robust base to create communication about their art, history and context. In the case study proposed here, the Medusa's Heads in Istanbul, Turkey, are the starting point for an investigation and exploration about the original architectures to which these statues were destined. Using digital solutions for survey, interpreting and disseminating the characteristics and a (possible) story about these ancient artworks. The protome of Medusa at the centre of this case study are situated in Istanbul: two of them are quite well known and are inside the Basilica Cistern, while the third one (at all the effects a double head, but with the two heads not separated from the same stone block) is kept in the Istanbul Archaeological Museum. The Basilica Cistern, Yerebatan Sarnici in Turkish (which means "Cistern sinking into the ground"), was built in 535 AD by Justinian. The peculiarity of these heads stands in their position inside the Cistern, used as build materials in the basements of two columns. Meeting these fragments push the visitors to wonder about their real origin, because it is quite evident that in this case the "spolia in se" has become "spolia in re"(accordingly to the concept from Richard Brilliant). They missed the apotropaic symbolic function of the horrid that drives away the horrid, but takes on a pragmatic character, it is clearly an element not made specifically for the cistern but taken and reused. The figure of Medusa is known in the mythological world and is a character of material interest since it has been part of the artistic scenario from its first appearances in the 8th century BC, surviving, thanks to the strength of such a character, to the present days, getting many new shapes and interpretations. The tasks of this research are quite essential: getting a high-quality survey of the heads; using the digital model as the base for virtual analysis and reconstructions; creating virtual environments presenting the artworks as they are and inside the digital version of the reconstruction hypothesis. The survey was done in two separate occasions, in 2014 and 2017, using a high resolution professional camera (Nikon D800e) and processing the set of shots in SfM photogrammetry software. Taking simple direct measurements on the artworks allowed to put in scale the digital models. After a proper treatment, the digital models were used as a base for the study and development of various reconstruction hypothesis. All the results of this phase were uploaded to the Sketchfab.com platform, an excellent solution to publish, share and discover 3D, VR and AR contents. The Sketchfab features were then exploited to create a first virtual visit to the Gorgons, controlling 3D animation and activating the Virtual Reality mode to make the model viewable by Virtual Reality devices. To create a simulation of the "Basilica Cisterna" the choice was for Unreal Engine, a perfect solution for creating a virtual environment for immersive devices, like the Oculus Rift, to access the digital version of the Cisterna and to offer a format that can be reused in any museum context. Inside the simulation, with the use of QR codes, the visitor can access detailed documentation about the place and the Gorgons, even the models loaded on Sketchfab.com are accessible within the Cistern virtual space. The access to multimedia material, like 3D models, rendering in 360 panoramic mode and VR/AR contents, gives to the visitors the opportunity to gain a clear idea about the nature of the protome. In this contribution, the procedures, issues and solutions adopted to move from the reality to its virtualization and integration with reconstruction hypothesis will be presented in detail, with video and links to report the reached results.