A Multimodal XR Framework for Heritage Engagement and Analysis: The Case of Torre del Mar in Borriana (Castellón, Spain)

The transition from Cultural Heritage (CH) digital documentation to dynamic, experiential heritage requires versatile workflows that engage diverse audiences. This paper proposes a scalable, multimodal eXtended Reality (XR) framework for the Torre del Mar (Castellón, Spain) and demonstrates how a single high-fidelity dataset can generate a comprehensive ecosystem of interactive experiences. Starting from a multi-source data fusion of UAV photogrammetry and Terrestrial Laser Scanning (TLS), a master model was developed to drive three distinct interaction pipelines. First, a phygital interface combines a modular, disassemblable 3D-printed replica with model-based Augmented Reality (AR), enabling tangible exploration of constructive details. Second, a collaborative Mixed Reality (MR) environment allows remote experts to co-inhabit the digital space for real-time analysis. Third, a multi-tiered Virtual Reality (VR) strategy optimizes the asset for PC-tethered, standalone, and WebVR platforms, balancing graphical fidelity with accessibility. The results validate a reproducible methodology that transforms technical survey data into an active knowledge system, effectively bridging the gap between scientific preservation and public dissemination while ensuring the long-term valorization of digital heritage assets.