Virtual restitution in the service of lost heritage. The case of the Valladolid collegiate church /cathedral of Santa María la Mayor

This article presents a virtual restitution of the interior of the Collegiate Church of Santa María la Mayor in Valladolid, a Gothic temple with Romanesque features that was dismantled between the 17th and 18th centuries. Through interdisciplinary research combining historical documentation, architectural analysis and digital modelling, the study recovers the spatial and artistic essence of the original building, giving it a new graphic life. The methodology falls within the scope of virtual archaeology, understood as a scientific discipline that uses digital technologies to rebuild, analyse and highlight lost heritage. In this case, the restitution is based on the study of preserved architectural remains, documentary sources and comparisons with contemporary temples, generating formal hypotheses that can be verified through three-dimensional (3D) representation. Using real-time visualisation engines such as Unreal Engine and Twinmotion, and applying physically based rendering (PBR) textures, a high-fidelity visualisation has been achieved that accurately reproduces the temple’s materiality, lighting and interior atmosphere. These tools, which originate from the fields of interactive design and video games, allow users to explore the space in real time and experiment with different lighting, colour and texture conditions, contributing to a more complete understanding of the monument. The process culminates in the creation of a dynamic video rendering and an immersive 360º virtual tour, structured around interactive points that offer textual, graphic and audiovisual information. These results not only allow architectural hypotheses to be tested and lost structures to be visualised, but also promote cultural dissemination, public participation and the creation of new avenues of access to heritage knowledge. This project thus exemplifies the potential of virtual archaeology as a tool for research, conservation and communication of lost architectural heritage.