A Framework for Digital Documentation and Virtual Reconstruction of Cultural Heritage

Cultural heritage provides tangible connections between contemporary society and the people, places, events, and cultural practices of the past. Historic buildings, monuments, archaeological sites, and artifacts, however, are inherently vulnerable to deterioration and loss. Natural hazards, climate-related impacts, armed conflict, development, tourism pressures, inadequate maintenance, and other human and environmental factors continue to threaten heritage resources throughout the world [1], [2]. Once significant physical fabric has been damaged or lost, conventional preservation methods alone cannot fully restore the information or experiences embodied in the original place. The development of digital documentation and visualization technologies has introduced new approaches to this challenge. Reality-capture technologies, including terrestrial laser scanning (TLS) and photogrammetry, can record the geometry and visual characteristics of existing heritage resources with high levels of detail [3]. The resulting digital data can be incorporated into three-dimensional (3D) models, such as Heritage Building Information Model (HBIM), and other digital environments for documentation, analysis, conservation, education, and public interpretation [4], [5]. At the same time, augmented reality (AR), mixed reality (MR), and virtual reality (VR) provide mechanisms through which these digital representations can be experienced interactively, allowing users to explore heritage resources independent of many physical and geographic limitations [6], [7], [8]. Digital heritage, however, involves more than reproducing existing physical conditions. The technological and interpretive requirements change considerably when a heritage resource is incomplete, exists primarily as archaeological remains, or has disappeared altogether. An intact historic building can be documented primarily from measurable physical evidence, whereas the reconstruction of a partially destroyed or non-extant structure may require the integration of archaeological evidence, archival documents, historical imagery, comparative examples, and scholarly interpretation. Consequently, as the amount of surviving physical evidence decreases, digital representation progressively shifts from documentation toward reconstruction, and the degree of interpretive uncertainty increases. Existing research has demonstrated individual applications of laser scanning, photogrammetry, 3D modeling, AR, and VR for heritage documentation and visualization [4], [5], [6], [7], [9]. Nevertheless, these technologies are frequently discussed as individual tools or applications rather than as components of a broader process linking the physical condition of a heritage resource to the appropriate method of digital interpretation. This paper, therefore, examines how digital technologies can be organized according to the physical condition and evidentiary basis of cultural heritage resources. Through a synthesis of previous digital heritage studies and illustrative applications, the paper proposes a conceptual framework that connects four general heritage conditions: intact, partially lost, largely lost, and non-extant, to corresponding approaches to reality capture, digital reconstruction, AR/MR, and VR. The framework is intended to clarify the transition from evidence-based digital documentation to increasingly interpretive virtual reconstruction and to support more deliberate selection of technologies for heritage preservation, interpretation, and public engagement.

Digital cultural heritage employs a range of technologies to document, reconstruct, and interpret historic buildings, monuments, archaeological sites, and artifacts. Reality capture methods such as TLS and photogrammetry provide detailed records of existing physical conditions and have been widely applied to cultural heritage documentation. Agnello et al. [4], for example, used laser scanning and surveying techniques to document the Cathedral of Palermo and support reconstruction of its earlier architectural configuration. Similarly, Caciora et al. [5] combined terrestrial and aerial photogrammetry to generate detailed 3D models of historic wooden churches in Romania. These applications demonstrate how measurable physical evidence can provide the foundation for accurate digital representations of surviving heritage. When heritage is incomplete or substantially altered, digital documentation increasingly becomes digital reconstruction. Three-dimensional modeling can combine surviving physical evidence with archaeological findings, archival documents, historic imagery, and other sources to represent missing or earlier conditions [7], [9]. However, reconstruction also introduces interpretation. As physical evidence decreases, decisions concerning the form and appearance of missing elements increasingly depend on historical evidence and scholarly inference [10]. AR and VR extend these digital representations into interactive heritage experiences. AR can overlay reconstructed elements or interpretive information onto surviving physical environments, making it particularly applicable to partially preserved sites [9]. VR can instead immerse users within a fully digital environment and is therefore suitable for heritage that is inaccessible, substantially altered, or no longer extant [6], [7], [8]. Recent research has further expanded VR from primarily geometric visualization toward interactive exploration and digital storytelling [7]. Collectively, these technologies form a cohesive set of approaches rather than independent applications. Reality capture primarily documents surviving physical conditions, while 3D modeling supports the reconstruction of missing elements, and AR/VR enables increasingly immersive forms of interpretation. The appropriate combination of technologies depends on the physical condition of the heritage resource, the availability of supporting evidence, and the degree of interpretation required. To examine these relationships, this study employs a qualitative synthesis of representative digital heritage studies rather than a systematic literature review. Studies were selected to represent different heritage conditions and digital approaches, including reality capture, 3D reconstruction, AR/MR, and VR, with particular attention to applications that relate surviving physical evidence to methods of digital documentation or reconstruction. The selected studies were comparatively examined across four dimensions: heritage condition, evidentiary basis, digital approach, and mode of digital delivery. Recurring relationships among these dimensions were then synthesized to develop the conceptual framework presented in Section 3.

Based on the literature reviewed above, this study proposes a framework that relates the physical condition of a cultural heritage resource to the availability of evidence, appropriate digital methods, and resulting forms of digital interpretation. As illustrated in Fig. 1, the framework organizes heritage resources into four general conditions: intact, partially lost, largely lost, and non-extant. Moving across this variety, the availability of direct physical evidence generally decreases while the need for interpretation increases. Table 1 summarizes the principal evidentiary characteristics, digital approaches, delivery modes, and levels of historical uncertainty associated with the four heritage conditions. The four conditions represent general categories along a continuum rather than rigid thresholds. Intact heritage retains sufficient physical fabric for its principal geometry and characteristics to be documented directly. Partially lost heritage retains substantial measurable fabric, but missing components require reconstruction using supplementary evidence. Largely lost heritage retains limited physical evidence, such that its overall form and spatial configuration depend primarily on archival, archaeological, comparative, or other interpretive evidence. Non-extant heritage lacks sufficient surviving physical fabric to provide the principal geometric basis for reconstruction. The distinction between partially and largely lost heritage therefore depends not simply on the proportion of fabric remaining, but on whether surviving measurable evidence or indirect historical evidence provides the primary basis for digital representation. For intact heritage, laser scanning, photogrammetry, and other reality-capture methods can document existing geometry and appearance with relatively limited reconstruction. The resulting datasets and 3D models can support documentation, conservation, virtual tours, and other applications. For partially lost heritage, reality-capture data from surviving fabric can be integrated with historical photographs, drawings, archaeological evidence, and archival records to reconstruct missing components. AR/MR can be particularly useful for presenting these reconstructed elements in relation to surviving remains. As physical evidence becomes more limited, digital reconstruction increasingly depends on indirect evidence and scholarly interpretation. For largely lost heritage, historical, archaeological, and comparative evidence may provide much of the basis for reconstructing overall form and spatial configuration, with AR or VR providing appropriate means of communicating reconstructed environments. For non-extant heritage, reconstruction relies primarily on archival records, archaeological research, historical descriptions, comparative evidence, and other indirect sources. VR can be particularly suitable in this context because a reconstructed historic environment can be experienced independently of its present physical condition. The framework therefore represents a general transition from reality-based documentation toward increasingly interpretive reconstruction. Importantly, greater technological capability does not necessarily imply greater historical certainty. As direct physical evidence decreases, digital reconstructions increasingly incorporate assumptions and scholarly judgment. Digital heritage projects should therefore communicate the evidentiary basis and associated uncertainty of reconstructed content rather than presenting all virtual representations as equally documented historical conditions. The proposed classification is primarily intended for tangible and spatial heritage for which physical condition and geometric evidence can inform digital representation. Its applicability to other heritage typologies—including movable artifacts, earthen structures, decorative surfaces, and especially intangible heritage—requires further investigation and may require additional or modified classification criteria.

The proposed framework can be illustrated through existing digital heritage projects representing different levels of physical preservation. The Cathedral of Palermo represents the intact end of the continuum. TLS and surveying were used to document the existing cathedral and establish a geometric basis for reconstructing its eighteenth-century configuration [4]. In this case, substantial surviving physical evidence allows reality capture to serve as the primary foundation for digital representation (Fig. 2). The Ak-Saray Palace in Shakhrisabz, Uzbekistan, illustrates a partially preserved heritage resource (Fig. 3). Only portions of the historic complex remain, requiring digital reconstruction to combine surviving physical evidence with historical and archaeological information. The integration of 3D modeling and AR allows reconstructed architectural elements to be interpreted in relation to the remaining structure [10]. This case demonstrates the transition from direct documentation toward evidence-based reconstruction. At the more interpretive end of the continuum, virtual reconstruction can provide access to heritage environments that survive only partially or whose original spatial experience has been substantially lost. Early work by Gaitatzes et al. [6] demonstrated this approach through immersive virtual representations of ancient Olympia (Fig. 4), allowing users to experience reconstructed architectural environments rather than only surviving archaeological remains. These applications demonstrate that the selection of digital technology should be driven by more than technological capability. The condition of the heritage resource and the strength of available evidence should determine both the reconstruction process and the form of digital experience. Reality capture is most effective when substantial physical fabric survives, while AR can connect reconstructed elements to existing remains and VR can communicate environments requiring extensive reconstruction. The framework also emphasizes an important limitation of virtual heritage: visual realism should not be equated with historical certainty. Highly detailed digital models can appear authoritative even when portions of the reconstruction depend on incomplete evidence or scholarly interpretation [11]. As digital heritage moves from documentation toward reconstruction, projects should therefore identify the sources supporting reconstructed elements and, where appropriate, communicate levels of uncertainty to users. Such transparency can preserve the educational and interpretive value of immersive technologies while maintaining scholarly credibility.

This paper proposes a conceptual framework relating the physical condition of cultural heritage to the evidentiary basis, digital approaches, and experience technologies used for documentation, interpretation, and reconstruction. The framework positions tangible and spatial heritage along a continuum from intact to non-extant resources. As direct physical evidence decreases along this continuum, digital representation generally shifts from reality-based documentation toward increasingly interpretive reconstruction. Reality capture, 3D modeling, AR/MR, and VR can therefore be understood as complementary approaches whose application should respond to heritage condition, available evidence, and the intended form of digital interpretation. The framework is not intended to prescribe fixed technologies for individual heritage conditions. Rather, it provides a structured basis for considering how physical evidence, interpretation, digital methods, and delivery modes interact in cultural heritage projects. Importantly, increasing visual realism and immersion should not be interpreted as increasing historical certainty. As reconstruction becomes more dependent on indirect evidence and scholarly interpretation, the evidentiary basis and associated uncertainty of reconstructed content should be clearly communicated. By integrating heritage condition, evidentiary basis, digital approach, delivery mode, and historical uncertainty within a common structure, the framework provides a basis for more deliberate and transparent development of digital heritage applications. Future research should evaluate and refine the framework across diverse geographic contexts, construction materials, heritage scales, and typologies, including wooden and earthen architecture, movable artifacts, and, where applicable, intangible cultural heritage. Such studies can also examine how different approaches to communicating evidentiary confidence influence user understanding, learning, and engagement.