Advancing 3D Cultural Heritage Digitization between the 5D Culture Project, the 4CH Project, and the Twin it! Campaign

The integration of advanced digital technologies is reshaping cultural heritage (CH) documentation, enabling new approaches to conservation, analysis, and dissemination. This paper presents an integrated and open digital workflow for the survey, management, and reuse of complex architectural heritage, using Villa Aldrovandi-Mazzacorati as a case study. The approach combines fixed-station laser scanning, terrestrial and aerial photogrammetry, and mobile SLAM-based mapping to generate high-resolution, reality-based 3D datasets. The proposed multi-sensor acquisition framework is critically assessed in terms of completeness, geometric accuracy, efficiency, interoperability, and long-term reuse. Results demonstrate that the integrated approach delivers reliable and comprehensive metric documentation while significantly reducing acquisition time compared with single-sensor strategies. The resulting HBIM model and associated web-based platform support structured information management, conservation planning, multidisciplinary collaboration, and online dissemination. In parallel, reality-based 3D meshes are successfully repurposed for immersive virtual reality (VR) experiences, enhancing accessibility and public engagement. By adopting open and standardized data formats, the workflow promotes long-term sustainability and FAIR-compliant reuse of digital heritage assets, offering a scalable and transferable framework for future 3D heritage initiatives across architectural and territorial contexts. Overall, the approach supports both specialist conservation workflows and public-facing dissemination, bridging the gap between technical heritage documentation and cultural interpretation.