Advanced digital modelling of the Torre del Mar (Borriana, Castellón): from digital fabrication to immersive experience through eXtended Reality (XR)

The sixteenth-century Mediterranean was neither a secure environment nor its coastlines, necessitating substantial defensive measures. To this end, fortifications were erected around urban centres and many towers were constructed to punctuate the coastal perimeter. The littoral of the Kingdom of Valencia was no exception; indeed, it was particularly affected by the presence of the Morisco population. Within this context emerges our case study: the Torre del Mar (Borriana, Castellón), an optimal site for the experimental methodology proposed in this investigation. Constructed between 1553 and 1558 by viceregal mandate, and subsequently documented by the engineer Giovanni Battista Antonelli in 1563, it constitutes a paradigmatic element of the coastal defensive system, whose comprehension may now be mediated through innovative communication forms. The principal objective of this research is the creation of a comprehensive and detailed digital model, which integrates data obtained through unmanned aerial vehicle (UAV) photogrammetry (specifically processed to maximise the level of detail of the external envelope) with a point cloud acquired through high-resolution terrestrial laser scanning (TLS), for the geometric and material characterisation of internal spaces. The resulting digital model fulfils multiple interpretative and communicative functions. Firstly, it constitutes the foundation for realizing a physical scaled replica, produced through digital fabrication techniques. The physical model decomposes the structure into twelve components, assemblable via magnetic connections. This solution enables dynamic exploration of the tower’s constructive elements. Secondly, the digital model is propaedeutic to the development of immersive eXtended Reality (XR) experiences: Virtual Reality (VR), accessible remotely; Augmented Reality (AR), for interaction with the physical model; and Mixed Reality (MR), aimed at creating collaborative environments. This research demonstrates how contemporary digital modelling methodologies offer innovative approaches for analyzing, interpreting, and disseminating fortified heritage.