3D technologies for cultural heritages

This study investigates Leonardo da Vinci's long-standing interest in milling technologies through the digital reconstruction of a pendulum-driven mill illustrated in the Codex Atlanticus. By tracing the chronological development of Leonardo's ideas across multiple sheets, this research highlights the continuity and evolution of his conceptual approach to energy transmission and mechanical automation. This work adopts a systematic design methodology to interpret and visualize the structural logic of the machine, integrating historical sources with engineering reasoning. The resulting CAD model reconstructs the key components (such as the gear train, escapement system, and pendulum) within a coherent architectural framework inspired by Leonardo's sketches. While the digital model remains a preliminary interpretation, it offers a historically grounded basis for future refinements. In particular, it lays the groundwork for potential physical reconstructions intended for museum display and public engagement. This study contributes to the broader understanding of Renaissance mechanical culture and the role of digital tools in heritage preservation and dissemination.

Keywords: ancient machines , CAD , engineering , heritage , history , Leonardo da Vinci , Mill , pendulum , technology , virtual model

The increasing interest in technologies such as Metaverse, Augmented Reality (AR), and Artificial Intelligence (AI) opens up numerous possibilities that have the potential to shape our daily experiences in the future. We investigated how integrating today's popular chatbots and multisensory AR technologies can create personalized museum visiting experiences. The paper outlines the concept of a digital assistant-based application for museum visits. The visitor, equipped with AR technology, can ask questions about the exhibits and receive precise and contextually relevant answers from the digital assistant who can virtually appear as an avatar with accompanying multimedia AR information. In the paper, we describe the implementation of a prototype of the application.

Keywords: Augmented Reality , Chatbots , Metaverse , Museums

The supply of automotive spare parts, especially for historic vehicles, is not guaranteed by car manufacturers. Usually, car restorers look for original components at flea markets and fairs, but often they have to produce replicas from broken parts or, worse, without information about the original parts. A possible support in mechanical craftsmanship comes from digital tools commonly used in industry today. With the goal of replicating a component that no longer exists, this paper provides a workflow that integrates traditional manufacturing technologies with computer-based tools. The core is the digital model, which is used to prototype and test the replica for functionality as well as simulate its manufacturing process. An engine valve cover of a historic racing car was chosen as a case study, for which information sources were practically unobtainable. Firstly, a 3D model and a 3D printed prototype were developed. Sand casting was chosen based on the original process and computer simulations allowed to reconstruct the casting equipment and define the best part design. A faithful and functional replica is then manufactured and assembled with the original engine, respecting the original part in terms of form, materials and production. The proposed design approach can be further adopted in different contexts requiring on-demand, one-off or small-batch production.

Keywords: 3D modelling , Additive Manufacturing , Car restoration , Component reproduction , Computer-Aided Engineering , Sand casting

Galleries, libraries, archives, and museums are nowadays striving to implement innovative approaches to adequately use and distribute the wealth of knowledge found in cultural heritage. A range of technologies can be used to enhance the viewing experience for visitors and boost the expertise of museologists, art historians, scholars, and audience members. The present work aims to provide an overview of current methods and most pertinent studies addressing the use of the innovative technologies for enhancing the fruition of artifacts in traditional museums in an effort to improve the public experience and education. For all the technologies discussed, the paper focuses on the main results obtained in literature and on their possible implementation in the museal context. The overview demonstrates the liveliness of the world of research in the field of technologies for the digital development of museums and how many technologies commonly used in industry are increasingly finding their way into the cultural sphere.

Keywords: 2.5D , 3D acquisition , Additive manufacturing , Artificial intelligence , Augmented reality , Linguistic tools , Museums , Storytelling

In a digital world where technological development allows the implementation of computer-based methods that can objectively support human activities, it is no more conceivable that activities such as the analysis, classification, and reconstruction of archaeological ceramics are made manually. This determines that expert operators are involved in time-consuming, tedious, poorly repeatable, and reproducible activities whose results depend on his/her experience. This problem concerns the need for robust and reliable automatic methods supporting the operator in these activities. To address these problems, in the last years, the University of L'Aquila research group published robust and reliable methods based on the codification of archaeologists' knowledge in recognizing the most significant geometric and morphological features of sherds. With such tools now available, producing more objective knowledge referring to a huge amount of sherds, the need arises to develop computer-based systems capable of sharing this knowledge. For this purpose, in this paper, a dedicated database is proposed. Particular efforts were made to implement an intuitive and interactive web interface with commands that co-determine the essential interaction of the archaeologist with the fragments in the traditional method.

Keywords: Automatic features recognition , Computer methods in archaeology , Innovative representation scheme , Semantic annotations , Web-based application

Physical or virtual models of ancient machines often play a key role in museum's exhibits, as well as in cinematographic works somehow focused in technological heritage. To obtain such models, complex design activities are required, characterized by strict co-operations among different stakeholders (i.e. designers, historians, artisans, museum staff, etc.). In recent publications, the systematic design methods originally conceived for industrial purposes, have been considered as valid supports also for the reconstruction of ancient machines. In this paper, a specific systematic design procedure is applied to support the fuzzy front-end of the process, concerning the reconstruction of a machine devised by Leonardo da Vinci. The machine is the Pendular Mill, which is characterized by important criticalities such as the enormous size, the complexity of the mechanism, and the missing information about key details. The result obtained in this paper points out a set of different possibilities for the design of physical models for a museum's exhibit, highlighting the issues to be faced for each hypothesized direction. The obtained information constitutes the underpinning for the next planning and design activities of a brand new model of the machine.

Keywords: Ancient machines , Engineering , Leonardo da Vinci , Systematic Design , Technological heritage

Over the last few years, significant interest has been addressed in developing computer-based methods to document and analyze fragments of ceramics sherds in archaeology. This is because traditional manual processes do not allow for an objective, repeatable, and reproducible analysis of the large quantities of material needed to fully understand and explain human practices in various cultural contexts, such as the economy, daily life, and the material expression of religious beliefs. In that context, this paper proposes a fully digital methodology resulting from the constitution of an international research group coming from different scientific backgrounds: archaeologists with specific skills and experience in fast 3D geometry acquisition methods and researchers who developed and published the only available computer-based process for recognizing the geometric and morphological sherds features analyzed by archaeologists. The proposed methodology consists of two main parts: 1. 3D acquisition of sherds with the construction of the discrete 3D manifold model based on the Structure for Motion technologies; 2. recognition, segmentation, and dimensional characterization of morphological and geometrical features based on the codification and algorithmic implementation of the knowledge used by the archeologists in the traditional method. The method was applied to analyze a set of 133 sherds excavated at Tell el-Burak (Lebanon) to obtain, through the analysis of the namely Phoenician carinated-shoulder amphorae, new insights into the economic organization of the Phoenician homeland. The method demonstrated the potential for objectively, repeatedly, and reproducibly analyzing large quantities of sherds. Furthermore, it allowed studying sherds by generating new high-level knowledge from those acquired from 3D models; in particular, this paper introduces new morphological features that help the archaeologist classify fragments from an analysis of the rim's shape.

Keywords: 3D archeology , Automatic feature recognition , Hierarchical rims clusterization , Phoenician amphorae , Pottery , Structure from motion

[No abstract available]

Museum institutions represent a narrative tool that can foster a renewed relationship between the community, cultural heritage and the local area. The MEDIA (Advanced Mul-timedia Digital Emotional Museum) project fits into the field of local museum heritage enjoyment and is based on research aimed at investigating visitors' cognitive and emotional processes through physiological techniques, such as electroencephalography (EEG). Through the case study of the Museum of Valdostan Craftsmanship of Tradition (MAV), this paper explores the potential related to the use of immersive digital technologies, such as virtual reality (VR), to enhance emotional response to heritage and culture and increase user engagement.

The metaverse, powered by XR technologies, enables human augmentation by enhancing physical, cognitive, and sensory capabilities. Cultural heritage sees the metaverse as a vehicle for expression and exploration, providing new methods for heritage fruition and preservation. This article proposes a metaverse application, inspired by the events of the Italian Resistance, promoting interactions between multiple users in an immersive VR experience while safeguarding intangible cultural assets according to an edutainment approach. The virtual environment, based on Ivrea's town hall square, provides in-depth information about the partisan's life and the historical value of its actions for the city. Furthermore, the application allows users to meet in the same virtual place and engage with one another in real time through the Spatial SDK. Before the public presentation, a heterogeneous group of thirty users underwent usability and engagement tests to assess the experience on both VR headsets and smartphones. Tests revealed statistically significant evidence that there is a genuine difference in users' perceptions of usability and engagement with different devices and types of interaction. This study highlights the effectiveness of adopting XR as a supporting technology to complement the real experience of cultural heritage valorization.

Keywords: cultural heritage , digital heritage , edutainment , metaverse , virtual reality

Retrievals of small and medium scale are one of the fundamental and most numerous parts of the entire museal heritage set. Their exposition represents an issue, looking for supporting structures that could be non-invasive, aesthetically pleasant, customized, and, last but not least, safe and stiff enough to avoid any damage to the artifacts. Through the usage of several engineering methods, starting from the retrieval and the exhibition requirements, optimized supporting structure can be developed. The procedure here reported and applied starts from the Reverse Engineering acquisition in order to obtain the 3D model of each retrieval, also comprehending color and texture information. After that, exhibition and preservation requirements, given by heritage experts, are translated into engineering requirements, with the usage of an immersive Virtual Reality environment. With these inputs, the developed Generative Design Method (GDM), using CAD, CAE and optimization tools synergically, can optimize the configuration of supporting interfaces with the artifact and then can generate a lightweight conceptual design through a generative design process. In this way, we can take into account all the given requirements, obtaining a lightweight support, topologically optimized, highly customized, non-invasive, possibly pleasant, able to resist in safety, and additively manufacturable. In this paper, the procedure is applied on different retrievals from Museo Civico dell'Agrocimino of Soriano nel Cimino, Italy, with different scales and materials, proving the robustness of the method.

Keywords: Cultural Heritage , Generative Design , Parametric Optimisation , Reverse Engineering , Virtual Reality

A submerged elevation located off the coast of Le Castella, a small village on the Ionian Coast of Calabria (Italy) populated for thousands of years that features notable archaeological remains from the Great Greece (Magna Graecia) and the Middle Ages, was investigated through in-depth, multidisciplinary, geoarchaeological research. This submarine elevation, once aligned with the marine terrace MIS 3 of Le Castella and still completely emerged between 10 and 8 ka years ago, slowly sank due to erosion and local tectonic-structural subsidence and was also favoured by a submerged normal fault that cuts the terrace in two. The dismantling and sinking of this part of the marine terrace has significantly changed the Late Holocene shorelines, with notable consequences on a topographic and archaeological level. In fact, one of the consequences of the sinking of this ancient promontory was the disappearance of two small islands that were reported to be right in front of Le Castella by numerous historical and cartographic sources. In the last decades, there has been a scientific debate over the existence of these islets, but no convincing evidence has been found about their actual presence up until now. This research, funded by the Marine Protected Area “Capo Rizzuto”, was conducted by means of underwater archaeological and geological surveys, geophysical seabed mapping systems, and both direct and instrumental optical surveys made with an Autonomous Surface Vehicle. The outcomes allow us to confirm the presence of these two partially emerged rock bodies up to half a millennium ago. In addition, the presence of anthropogenic extrabasinal materials in a marine area corresponding to one of the highest points of the submerged elevation allows us to define the exact position of one of the two islets. These archaeological findings have been subject, for the first time ever, to a thorough topographical and architectural analysis, then compared with other near and very similar submerged structures. On the basis of these comparisons, the findings should be attributed to the Byzantine Age or, at most, to the Middle Ages. In-depth archival research on portolan charts and navigation maps, in many cases unpublished and dating from the Middle Ages to the early 18th century, supports the results of our marine investigations from a historical point of view.

Keywords: Calabria , coastal geoarchaeology , coastline change , coastline erosion , Ionian Sea , Late Holocene , marine geology , marine geophysical investigations , Marine Protected Area of Capo Rizzuto , maritime and underwater archaeology , underwater 3D surveying , underwater acoustics

Three-dimensional acquisition and reproduction technologies are often exploited in cultural heritage field for a variety of applications such as conservation, restoration, and dissemination. Another valuable use of 3D data is to make exhibitions more accessible to visitors with impairments, allowing them to fully experience and enjoy the acquired objects. In this short paper, we explore the accessibility inherently provided by 3D representations of real-world objects, with a particular focus on the quality of the models and 3D printing, as well as the presentation aspects. To this end, we propose to apply a state-of-the-art saliency-driven process, generating a fixation map that identifies the object's salient areas that need to be reproduced with a higher definition during the 3D printing to improve the object accessibility. We present a case-study involving the full process of 3D scanning and printing the Coats of Arms in Palazzo Bo (Padova, Italy) to make them accessible to visitors with visual impairment. We employed different scanning techniques and applied the attention mechanism on acquired data to obtain the object salient areas and drive the printing process accordingly. Preliminary tests involving some participant feedback reveal that printing the objects with a variable detail level allows the visitors to have a better understanding of the object as a whole and to appreciate the relevant details.

Keywords: 3D printing , 3D reconstruction , Accessibility , Cultural heritage , Fixation prediction

The current context is characterised by the speed of change in the technological sphere and in particular by the interconnection—to the point of overlaying—between physical and digital space. This stimulates consideration on the opportunities to explore the new frontiers of knowledge through advanced technologies and unprecedented cognitive-sensory perceptions, both from the user's viewpoint and from that of the researcher. The chapter provides a critical-analytical reflection on accessibility and multisensory issues as fundamental tools for transferring multilevel knowledge between physical and digital. Based on this study, it proposes the configuration of immersive knowledge-sharing environments where cultural heritage and scientific research intersect, placing the user at the centre of experience. The augmented, multilevel fruition, the tracking within the multisensory environment of psycho-physiological and behavioural users' data, together with the assessment of experience itself, have guided the design experimentations undertaken for the new layout of the Museum of Contemporary Mediterranean Ceramics in Cava de' Tirreni. This was conceived as a multisensory and accessible phygital laboratory of inclusion and dialogue, a dynamic and adaptive space for sharing and experiencing knowledge.

Keywords: Accessibility , Immersive experience , Multilevel knowledge , Multisensory adaptive fruition , Phygital , Physical-digital relationship

The reusability of informative content throughout the building life cycle is a current issue in the AEC sector. One of the cornerstones of BIM is to guarantee the availability and portability of data which, against a greater initial investment for the construction of the model, will offer a multidisciplinary and integrated tool to support all possible operations on the building. The issue becomes even more complicated in the case of cultural heritage or existing structures where the information process starts directly from the operation stage (management and maintenance phases) and provides, through reverse engineering methodology, an Asset Information Model. It is therefore essential to keep track of the levels of accuracy of this content, in relation to the geometric and informative attributes of all the objects that make up the model. Starting from a careful analysis of the state of the art related to these issues, this paper proposes a possible approach to the statistical treatment of uncertainties related to geometric attributes in case of Historic or Existing BIM, differentiating between the products of the survey and those of the subsequent parametric modelling.

Keywords: Detected accuracy , Modelled accuracy , Scan-to-BIM

Preface and Acknowledgements (Editorial)

Keywords: Editorial

Post-processing pipeline for image analysis in reverse engineering modelling, such as photogrammetry applications, still asks for manual interventions mainly for shadows and reflections corrections and, often, for background removal. The usage of Convolutional Neural Network (CNN) may conveniently help in recognition and background removal. This paper presents an approach based on CNN for background removal, assessing its efficiency. Its relevance pertains to a comparison of CNN approaches versus manual assessment, in terms of accuracy versus automation with reference to cultural heritage targets. Through a bronze statue test case, pros and cons are discussed with respect to the final model accuracy. The adopted CNN is based on the U-NetMobilenetV2 architecture, a combination of two deep networks, to converge faster and achieve higher efficiency with small datasets. The used dataset consists of over 700 RGB images used to provide knowledge from which CNNs can extract features and distinguish the pixels of the statue from background ones. To extend CNN capabilities, training sets with and without dataset integration are investigated. Dice coefficient is applied to evaluate the CNN efficiency. Results obtained are used for the photogrammetric reconstruction of the Principe Ellenistico model. This 3D model is compared with a model obtained through a 3D scanner. Moreover, through a comparison with a photogrammetric 3D model obtained without the CNN background removal, performances are evaluated. Although few errors due to bad light conditions, the advantages in terms of process automation are consistent (over 50% in time reduction).

Keywords: Close range photogrammetry , CNN , Cultural heritage preservation , MobilenetV2 , Reverse engineering , U-Net

Conventionally, visitors of exhibitions cannot directly interact with artworks but remain mainly passive. This work presents a new way to discover paintings through an extended reality application with the aim of enhancing visitors' engagement. The workflow consists of digitally recreating a painting. All its constitutive elements are contoured and then removed by the artwork. These elements will be unveiled by the visitors with gesture interaction. The discovery of each element is followed by additional information on the subject. The application also proposes an alternative experience where the user paints the components of the artwork with gestures. The hands' position was tracked by the Leap Motion Controller, an optical sensor by Ultraleap. The process has been applied to one of the Tintoretto's pieces of art: “L'Annunciazione del Doge Grimani”. The extended reality application has been experienced by over twenty thousand visitors at the dedicated exhibition. Numerous positive comments received from both visitors and guides are encouraging.

Keywords: Cultural heritage , Exhibition , Extended reality , User interaction

This paper presents a Generative Design Method (GDM) for highly customised Cultural Heritage applications concerning the exhibition and conservation of pottery. As a fundamental requirement, archaeological finds must be preserved in their structural integrity. Additionally, when present, the exposition supports must be aesthetically pleasant meaning that they must be non-invasive in the field of view of the observer. Furthermore, each artefact presents a unique geometry, hence its supporting structure must be designed accordingly. The proposed GDM considers these requirements, adopting a synergy of CAD, CAE, and optimisation tools. It is developed through two phases. The first phase, P1, concerns with the structural integrity of the fragment. In this phase, a Parametric Modelling approach is chosen for its ease of use both in the Finite Element Analysis evaluations of artefacts and in the design and optimisations of feasible supporting structures. The output of the phase P1 is the optimised configuration of the functional elements of the support ('Ci ') which are the interface region between the support itself and the fragment of pottery. They represent the input of the second phase, P2, that aims to generate lightweight concepts for the complete supporting structure considering the optimal 'Ci ' configuration. During this phase, an aesthetics criterion (related to the minimisation of the support's visibility) is also considered to achieve non-invasive supporting structures. Doing so, the GDM provides informed decisions in the early stages of the design activities with a simulation driven approach oriented to manufacturing. In this way, users are able to focus on design requirements since the concept's variants are generated by means of an optimised configuration of standardised components ('Ci') and obstacle geometries.

Keywords: Cultural Heritage , Generative Design , Parametric Modelling , Parametric Optimisation

Blind and visually impaired people are mostly excluded in enjoying visual artwork yet. Even if the effectiveness of tactile supports has been proven in previous studies, these are difficult to realize, since they are commonly handmade. In this paper, a set of computer-aided interactive tools for a semi-automatic reconstruction of tactile bas-relieves is proposed. Starting from the digital picture of a painting, this set make it possible to retrieve a 2.5D reconstruction of a scene in the form of flat-layered bas relief, which means that the scene is reconstructed solely by means of geometric primitives such planes, cylindrical surfaces, conical surfaces and generic (curve) surfaces. Tools have been specifically thought to obtain tactile bas-relieves of architectural scenes. Unlike typical handmade crafting, the proposed tools do not require specific user skills or training. In fact, user is only asked to select points (i.e., to detect a vanishing point) or segments of the picture to obtain a specific surface. Tools have been designed, optimized, and adopted to realize the tactile bas-relief of the painting Piazza San Francesco (unknown artist, Museo Civico di Arte Antica - Pistoia), within the research activities related to ARTE project (Augmented Readability Tactile Exploration), co-founded by Cassa di Risparmio di Pistoia e Pescia.

Keywords: Blind , Shape from single image , Tactile bas-relief