This paper aims at presenting the recording and modelling work developed in the framework of restoration and conservation activities for the Basilica di San Giacomo in Como, Italy, whose construction started in the 11th century. The project started in 2022 and involved the application of the Historical Building Information Model (HBIM) methodology through a Scan-to-BIM approach was assessed. High-detailed 3D survey techniques were used to acquire the specific shape of the church and annexed buildings. Then, through different modelling strategies, the HBIM environment allowed the representation of all the architectural elements. The purpose of this model is to have essential support to plan the restoration activities and to give the different experts involved a single three-dimensional tool for managing all the information during the development of the construction works. The possibility to update the model over time with geometric and non-geometric information will provide a powerful tool also for other future activities, such as the installation of a monitoring system that could reveal the displacements of bearing elements of the church.

One of the main objectives of today's archaeological sites and museums is the development of research, understood as the interpretation and contextualisation of tangible and intangible cultural heritage to broaden the knowledge and accessibility of archaeological parks often unknown to visitors and the public on a large scale. In this perspective, the Appia Antica Archaeological Park aims to support research in digitising infrastructures and archaeological contexts of high historical and cultural value to plan short- and medium-term preservation and maintenance projects. In this context, unmanned aerial vehicles (UAVs) are tools with enormous potential in survey, inspection and digitisation, providing the basis for the subsequent phases of data interpretation, representation and material analysis. Thanks to the photorealistic reconstruction of dense structure from motion (DSfM) in the application of structural inspections, today it is possible to intercept the geometry and material conditions of small, medium and large structures, reducing the costs of inspections, limiting the interruption of the public and providing professionals and visitors with a better volumetric understanding of the system. However, inserting information that gradually accumulates throughout the process requires advanced 3D digital representation techniques, such as HBIM (historic building information modelling), scan-to-BIM approach and interactive forms, such as virtual and augmented reality (VR-AR). For these reasons, this study summarises the experience and lessons learned from the UAV inspection of three research case studies at archaeological, architectural, and infrastructure scales to increase awareness of the Roman-built heritage.

The Altamura Man and the paleontological remains are situated within a complex context encompassing logistical, geological, paleoenvironmental, and cultural perspectives. This context is exceptionally well-preserved but also fragile, requiring its preservation due to its unique nature. Unresolved inquiries exist in various disciplines, such as archaeology, biocultural studies, ecology, and geology, pertaining to karst formation, taphonomic dynamics, and the cultural and ecological context of the Neanderthal individual found in the cave. Interdisciplinary research was necessary to address these complex questions and understand the broader context of the Lamalunga Cave. Climate change also necessitated attention to preserving the cave's microclimate and monitoring potential biodegradation. Digital technologies, including photogrammetry and laser scanning, were crucial for monitoring and safeguarding the cave's cultural heritage. Digital representation, 3D modelling and Digital Twin were essential for managing the cave's intricacies, analysing its values, and enhancing visual communication. The management of the Lamalunga cave aimed to promote scientific interpretation, safeguard the cave, and provide tools for understanding, storytelling, and further investigation. It was essential to utilise available methodologies and technologies while avoiding destructive interventions. Contemporary technologies have revolutionised the archaeological and paleoanthropological domains, enabling remote study and preservation. Protecting and comprehending the cultural heritage of the cave is linked to its usability, which can be enhanced through digital documentation methodologies to inform visitors about the karst context and promote social and economic development.

The Faces Revealed Project takes its lead from innovative research trends that see the combination of different but interconnected skills and competences. It aims at contributing to the study of ancient Egyptian coffins by developing a new and efficient methodology based on fast, simple, cost-effective, and portable technique allowing the acquisition of precise and accurate gemetric data. This technology will provide further insights into the manufacture, production, workshops, and possibly the ancient reuse of the Yellow Coffins and may also constribute to the creation of a new way of classifying these coffins.

2020 meant the loss of 41.5 million visitors for Italian museums, monuments and archaeological sites. The regions that drive tourism and the Italian museum paid the price in terms of visitors and income. In this context, virtual museums have been taking on new forms of interaction, communication and sharing of information, overshadowing traditional applications based on sharing collections through static images or simple panoramas. Virtual Reality (VR) and Augmented Reality (AR) provide the end-user with more innovative learning with the latest technological advances and digital tools. Thanks to the integration of the latest 3D modelling and digital survey techniques with the Visual Programming Language (VPL) and eXteded Reality (XR) development platforms, the authors propose a scan-to-BIM-to-XR method based on different forms of architectural representation, digital survey (terrestrial and aerial) and building archaeology able to transmit the tangible and intangible values of the different types of architectural artefacts, from the large scale (building and its urban context), medium (art collections, sculptures, museum itineraries) up to the small scale (building archaeology) of one of the most important historical buildings in the city of Rome.

The study presents a part of the operational framework of the “Project for Infrastructure and Strategic Strengthening of the Somali National University”, funded by the Italian Agency for Development Cooperation. The project, coordinated by Politecnico di Milano, aims to reconstruct the Gahayr campus of the Somali National University of Mogadishu, which is today almost destroyed due to the civil war. The preliminary phase for reconstruction is a detailed survey of the buildings and the area over which the Campus will be re-built. In a normal situation, the team in charge of the survey would have gone on-site in Mogadishu; nevertheless, the risky local conditions and the Covid-19 pandemic made it impossible to have foreign personnel on-site. Consequently, the choice was to train a local team remotely, giving them the theoretical and practical instruments to face a complete 3D survey of the area and the buildings. Harsh times cannot stop works and activities that usually need the presence of the survey team on the field. Careful planning of the activities, the online staff training and the continuous sharing of the information permitted to get high quality 3D metric results quickly and to have at disposal all dimensional and qualitative valuable information for the project, usable in real-time by the designers and architects without going directly on the site.

Virtual museums should not live on the internet through traditional applications sharing collections through simple panoramas or static images and descriptions but reach novel innovative and interactive forms of Virtual Reality (VR) and Augmented Reality (AR), providing a more creative, intimate, personal learning experience. For this reason, the authors propose a method based on advanced Information Technologies (IT) to fully return the tangible and intangible values of different type of works of art. The primary purpose of this study is to create a system of virtual environments through which the digital user, mainly the visitor of an unconventional museum, will be able to physically interact, through visual and tactile methods, with 3D digital models of sculptures, information, and art objects. Thanks to the integration of the latest 3D modelling and digital survey techniques with the Visual Programming Language (VPL) and eXteded Reality (XR) development platforms, authors propose new levels of interactivity between users and Interactive Virtual Objects (IVOs) capable of coming to life, sharing new forms of real-time human-computer interaction for VR-AR enabled gaming experiences and virtual museums, using multiple devices such VR headset, web-based AR platforms, mobile phones, tablets, and PC workstation.

This study aims to enrich the knowledge of the monument Arco della Pace in Milan, surveying and modelling the sculpture that crowns the upper part of the building. The statues and the decorative apparatus are recorded with the photogrammetric technique using both a terrestrial camera and an Unmanned Aerial Vehicle (UAV). Research results and performance are oriented to improve computer vision and image processing integration with Unmanned Aerial System (UAS) photogrammetric data to enhance interactivity and information sharing between user and digital heritage models. The vast number of images captured from terrestrial and aerial photogrammetry will also permit to use of the Historic Building Information Modelling (HBIM) model in an eXtended Reality (XR) project developed ad-hoc, allowing different types of users (professionals, non-expert users, virtual tourists, and students) and devices (mobile phones, tablets, PCs, VR headsets) to access details and information that are not visible from the ground.

Abstract. In the last decades, thanks to the development of eXtended Reality (XR) development platforms, research studies have envisaged new possibilities for disseminating tangible and intangible values of the past through historical virtual reconstructions. More recently, experimentation in the field of virtual archaeology has led to the development of interactive experiences based on advanced virtual and augmented reality (VR-AR) technologies. In this context, the authors intend to support the transmissibility of the historical and cultural background through validated and sustainable workflow-oriented to create virtual historical reconstruction using different sources such as 3D survey (laser scanning and digital photogrammetry), Historic Building Information Modelling (HBIM) models and historical reports. The XR project’s development included reconstructing the main historical sections and water basins of the Cerchia dei Navigli in Milan: the Conca dell’Incoronata, the Conca di Viarenna and Via Senato. The main objective is to achieve realistic and suggestive Virtual Visual Storytelling (VVS), recreating the atmospheres and scenes of everyday life when the waterways were still present. The result is engaging content on an emotional level, which leaves the visitor with dynamic memory and the feeling of reliving lost moments.

In recent years we have witnessed how technology applied to built heritage has exponentially changed the daily practices of the various experts involved in the life cycle of buildings. The techniques of representation of historical architecture have been able to make use of new 3D survey tools as well as research methods capable of managing a large amount of data while improving the level of information (LOI) and accuracy of the surveyed artefacts. On the other hand, professionals still have to make use of a large number of exchange formats in order to share their digital representations (3D, 2D) and analysis. For this reason, this paper describes the research approach followed to obtain “standard” architectural representations of a heritage building in the Cultural Heritage domain. The word “standard” is used in its original meaning: “something established by authority, custom, or general consent as a model or example” (Collins Dictionary). In this context, 3D models have a primary role in the workflow because its position is in-between the 3D survey techniques that come first and the restoration/maintenance activities. The authors’ thought is that the workflow should be as smooth and sustainable as possible to have an effective standardization and collaboration among disciplines, sectors and technicians working in the different study areas.

This paper describes the methodology employed in 2020 to perform the 3D survey of the Tomb TT214 at Deir al-Medina (Egypt). The aim of the archaeological mission was to integrate the evidence collected in the past on this tomb with a fresh survey a detailed study of some of its elements and an evaluation of its needs in terms of conservation. In order to achieve this result, the collapse that blocked the entrance to the burial chamber had to be removed, the courtyard was cleared, and the decorated walls and blocks were inspected and surveyed. Digital imaging was used to document all these phases and portions of the work. The aim of the survey team was to identify the most efficient combination of tools and methods to be used during these logistically complex operations, during which it was necessary to coordinate the work of various specialists and of the workmen, as well as to negotiate with the environmental difficulties and constrains. The survey was conducted at two scales, one for the architecture of the funerary complex and one for minute details such as inscriptions and decorations. Beside the routine process, both sets of data underwent a further level of elaboration, in order to extract and highlight further information. The final result of the survey was a navigable 3D model able to produce different outputs, all designed to support the archaeologists on the field and during the post-fieldwork phase of the elaboration of the results. The elaboration of such an integrated model may be paired to the progressive construction of a Digital Twin, a term born from the manufacturing and industrial realm but that may be successfully exported into the archaeological realm.

This study-experiment analyses the syntactic and semantic ties among images, texts and maps by using a blend of Geomatics and Linguistics techniques. Specifically, this work deals with the construction of a map on the basis of a written text representing a pictorial description of a panoramic mountain view. The aims are to demonstrate the aforementioned linkages and to measure the quality results in quantitative terms: the whole procedure is performed in seven steps (described in the introduction) and it closes with a final statistical evaluation. In order to achieve this task, a photograph was taken from the top of Mount San Giorgio, in Switzerland (Canton of Ticino), near Lake Lugano.

This work starts from the request to have a physical high-resolution 3D model of the external, anthropoid coffin of the scribe Butehamon, held at the Museo Egizio, Turin. At the time of writing, a replica of the coffin, based on this survey work, functions as final and focal installation of the temporary exhibition Archeologia Invisibile of the Museo Egizio, Turin, running from March 2019 to January 2020. The replica acts as support for a micro-mapping installation meant to re-project a pattern of images onto the coffin’s surface, including the results of different radiometric and colourimetric analyses performed in the recent past by Museo Egizio and Musei Vaticani. This collaborative work encouraged a thorough discussion on the interaction between scientists and humanists engaged in the study of archaeological finds, on the needs and expectations of both sides, and on the technical problems relating to handling objects of different sizes.

Since 2008, an intense survey has been underway in the Milan Cathedral. The operations, over the years, have been conducted with laser scanner and photogrammetry choosing or integrating the different methodologies according to the environment, the necessary "drawing" to support the different sites' maintenance operation but always concurrently with the evolution of the method and the software. The "principal actor" of conservation activities is the "marble block." The Veneranda Fabbrica organizes the activities identifying the areas that are in need of intervention and identifying which blocks will be affected by replacement operations, tessellation, or consolidation. Thus, the objective of the survey activities and the subsequent modeling phase was to build a detailed 3D model in which the marble blocks are easily recognizable in terms of their shape, size, position, and texture (only for the outer part). All the elaborations produced, the 3D models, the two-dimensional representations, and the orthophotos, allow for the identification of the blocks, as to provide proper technical support for site operations. In parallel with the survey and modeling activities, an ad hoc online information system was created to support the construction site activities in a smart manner. The system allows for the consultation and the sharing of the 3D models and all the data necessary for maintenance operations of the entire Cathedral.

Since 2011, the 3DSurvey Group of Politecnico di Milano organises an annual summer school programme entitled ‘Laboratory of Places, Ghesc and surroundings, history, survey, evolution’. This activity is patronised by the International Council on Monuments and Sites (ICOMOS) Italia and developed in collaboration with the Canova Association. This is a non-profit organisation founded in 2001 in the mediaeval village of Canova (Oira di Crevoladossola, Italy) and it is an institutional member of ICOMOS Italy since 2010. Its primary goal is the preservation and enhancement of rural, mediaeval stone architecture. From 2017, the summer school is also sponsored by ISPRS society. The case study of the course is the charming, abandoned mediaeval village of Ghesc, located in the hamlet of Montecrestese, Domodossola (Italy). There, the Laboratory aims to create a workspace where students, freelancers, teachers and members of the association can work to the documentation of the ancient village and actively contribute to its rediscovery and conservation. In particular, the research activity carried out in recent years by 3DSurvey Group and Canova Association deals with all the historical and architectural artefacts in the Ossola territory, even if they do not belong to the category of monumental bounded works. The general rural architecture also includes suburban complexes made up of buildings that do not have unique architectural values by themselves but considered together represent the construction tradition of the Ossola Valley.

The illustration of the experiment to construct a map, starting from a written text, assigned and prepared to specifically describe theimage of a mountain landscape, is presented with the aim of demonstrating its actual feasibility and measuring the quality obtained,in quantitative terms.

In the architectural survey field, there has been the spread of a vast number of automated techniques. However, it is important to underline the gap that exists between the technical specification sheet of a particular instrument and its usability, accuracy and level of automation reachable in real cases scenario, especially speaking about Cultural Heritage (CH) field. In fact, even if the technical specifications (range, accuracy and field of view) are known for each instrument, their functioning and features are influenced by the environment, shape and materials of the object. The results depend more on how techniques are employed than the nominal specifications of the instruments. The aim of this article is to evaluate the real usability, for the 1:50 architectonic restitution scale, of common and not so common survey techniques applied to the complex scenario of dark, intricate and narrow spaces such as service areas, corridors and stairs of Milan’s cathedral indoors. Tests have shown that the quality of the results is strongly affected by side-issues like the impossibility of following the theoretical ideal methodology when survey such spaces. The tested instruments are: the laser scanner Leica C10, the GeoSLAM ZEB1, the DOT DPI 8 and two photogrammetric setups, a full frame camera with a fisheye lens and the NCTech iSTAR, a panoramic camera. Each instrument presents advantages and limits concerning both the sensors themselves and the acquisition phase.

Nowadays, with the spread of the BIM technology in the Cultural Heritage field, it is important to find, case by case, a method that permits to manage the archeological and architectural artifacts considering their personal needs. In this case, the project focuses on a portion of the roofs of the Milan Cathedral, chosen for the complexity and richness in shapes of the components, which leads to difficult survey operations. The target was to experience complex methods of multi-sensor and multi-scale data acquisition and to build an infographic three-dimensional reality-based model in order to help and manage the conservation activities of the building. The complexity of the Cathedral’s late gothic style represents a hard challenge for the application of the innovative surveying methods and for modelling with a BIM-oriented software. For this reason, the experiment was made with two different modelling methods (one is object-oriented modelling BIM and the other is based on the use of NURBS surfaces), in order to find the differences between the two, in terms of managing the survey data, modelling, accuracy of the model, time required to create it and typology of data that they are able to visualize and insert. The result of this work is an example of methodological approach that can enhance the widespread application of this innovative technology for restoration or maintenance activities of built heritage.

The research is an analysis of the recording, reconstruction and visualisation of the 3D data of a XVIII century watermill, identified in an emergency archaeological excavation during the construction of the mini-hydroelectric plant on the bank of the Adda river in the municipality of Pizzighettone (Cremona, Lombardy, Italy).The work examines the use and the potentials of modern digital 3D modelling techniques applied to archaeological heritage aimed to increase the research, maintenance and presentation with interactive products. The use of three-dimensional models managed through AR (Augmented Reality) and VR (Virtual Reality) technologies with mobile devices gives several opportunities in the field of study and communication. It also improves on-site exploration of the landscape, enhancing the "minor" archaeological sites, daily subjected to numerous emergency works and facilitating the understanding of heritage sites.