Virtual 3D-Reconstruction of Interiors in Studies of Historical and Cultural Heritage: a historiographical review

Malandina Tatiana Vladimirovna Postgraduate student, Historical Information Science Department, History Faculty, Lomonosov Moscow State University 27 Lomonosovsky ave., building 4, Moscow, 119192, Russia malandinatanya@gmail.com Other publications by this author

Introduction

Virtual 3D reconstruction of architectural and historical and cultural heritage monuments is today one of the most relevant and actively developing new areas of interdisciplinary historical research. This direction is also being developed within the framework of the history of architecture, where digital technologies are organically combined with domestic historical and architectural traditions in the field of preservation and restoration of architectural heritage ^[1]. The issue of the specifics of the development of virtual reconstructions of cultural heritage in the research projects of historians and architects requires separate consideration.

 It should be noted that the degree of elaboration of the problems of 3D reconstruction of various types of lost interiors of cultural heritage objects against the background of an impressive number of high-quality scientifically based reconstructions of the exteriors of monastic and manor complexes, temple structures, urban development is small. But it is the historical interior that is a valuable source that can tell both about the historical epoch in question, the culture of everyday life inherent in it, and about the personalities of its creators and owners.

The purpose of the article is to analyze the literature and design work related to the experience of creating virtual 3D reconstructions of historical interiors. This is necessary for the search and adaptation of methods of working with historical sources, visualization of the results of reconstruction and its interpretation.

The development of the problems of virtual 3 D interior reconstruction in historical research

The interdisciplinary field of virtual 3D reconstruction of lost cultural heritage sites is relatively young. Virtual 3D interior reconstruction is one of its key least developed topics, along with landscape reconstruction, urban reconstruction, monastery and palace complexes, castles, reconstruction of individual artifacts, etc.  

The beginning of the study of the application of three-dimensional computer modeling techniques in historical research was initiated in the 1980s by foreign researchers.

The fact is that the development of digital architectural visualization using automated (architectural) design is directly related to the technical developments of both hardware and software. Its roots go back to the 1960s, when Ivan Edward Sutherland developed SKETCHPAD, the first computer program to use a full-fledged graphical interface, at the Massachusetts Institute of Technology (MIT) while working on his doctoral dissertation, published in 1963^[2]. This innovative program for the first time provided an opportunity for a person and a computer to interact using a graphical interface.

Since at first the available technology did not meet the requirements of architects, it was mainly used for design in the engineering industry. Even in the 1970s, automatic design systems (CAD) were limited to the image of two-dimensional spaces and may have been comparable to something like an electronic drawing board. In addition, the technology was not available to small companies that could hardly afford to pay for CAD maintenance. Nevertheless, back in 1973, archaeologist J. D. Wilcock, in addition to the four possible main applications of computer technology in archaeology, identified the reconstruction of culturally significant buildings and monuments as a vital means of obtaining knowledge ^[3].

The improvement of CAD technology in the 1980s made it possible for the first time to create a three-dimensional virtual model of architectural structures on a computer. In 1984, J. Clark, a former professor at the Massachusetts Institute of Technology, developed an innovative 3D object representation procedure at his company SGI (Silicon Graphics Inc.), which he founded in the early 1980s. Initially, Clark was focused on developing a sufficiently powerful semiconductor chip (Geometry Engine) that would allow small computers to create complex three-dimensional graphics. The idea became revolutionary because before that, graphical modeling was often (if not only) performed on large mainframe computers (https://www.hpe.com/us/en/about.html ).

The 1980s were a turning point: archaeologists turned out to be the pioneers of the use of 3D modeling in historical research. British archaeologist P. Reilly ^[4], as well as archaeologists S. Ratz ^[5], P. Miller and D. Richards ^[6] became pioneers of the systematic development of this area of scientific activity. In his review of the development of virtual reconstructions in academic research, X. Messemer noted that one of the first contributions to the topic of 3D technologies was made by archaeologist B. Frisher at the conference "Computer Applications in Archaeology", held in 1985 ^{[7, p.24]}.

The very first virtual 3D reconstruction of architectural heritage based on archaeological data was created in the UK between 1984 and 1986. Hosted at the IBM British Science Center, the project was dedicated to the history of the construction of the Old Cathedral in Winchester, Hampshire, an Anglo-Saxon church of the early Middle Ages, replaced by the current Winchester Cathedral in the XI century (http://3dvisa.cch.kcl.ac.uk/project12.html ). This project included not only the reconstruction of the exterior, but also became the first visualization of attempts to recreate the historical interior in three-dimensional graphics (see Figure 1). The computer reconstruction could be viewed as a two-minute video at the exhibition "Archaeology in Britain: New Views on the Past" at the British Museum in London from July 1986 to February 1987 of the year. The video contained a preset route based on a 3D model and reproduced both the interior and exterior views of the Old Cathedral.

Other versions of the reconstruction were created for television broadcasts in the UK and reflected the almost 400-year history of the construction of this church (648-1000). The digital implementation was created using the Winchester Solid Modeller (WINSOM) software, which in this case was used for the first time in the field of archaeology. Drawings and reconstructions created by archaeologist B. Kjellbai-Biddle served as the basis for digital modeling. They were re-founded on archaeological excavations in the 1960s, which revealed the partially preserved foundation of the old church. As a result, the digital model was not only exhibited in the museum, but also presented to a wide audience in several programs on British television ^[8]. The interior of the cathedral within the framework of this reconstruction looks schematic, nevertheless it conveys the structure of the internal organization of the building, its main elements and features, according to which the spatial location of parishioners and clergy can be traced.

The main achievement of the research on the virtual reconstruction of Winchester Cathedral is that its developers have formed the provisions that formed the basis of many subsequent similar developments:

1. Formation and analysis of the source base and modeling of the object;

2.                     Visualization and presentation;

3.                     Interpretation of the acquired knowledge.

Fig. 1. General view of the reconstruction of the Old Cathedral in Winchester, created at the British IBM Research Center in 1984-1986: interior and exterior (http://3dvisa.cch.kcl.ac.uk/project12.html )

The next project is an equally significant study in terms of the first steps in the development of research programs on virtual reconstructions of lost architectural monuments and their interiors. It is a three–dimensional reconstruction of Cluny III in 1989 - one of the earliest projects aimed at developing unexplored territories in the field of reconstruction of specific buildings (https://strabic.fr/Cluny-III-en-3D ).  Cluny III is an expression used to refer to the third stage of construction work in the French Abbey of Cluny (Sa?ne-et-Loire department), carried out at the turn of the XI—XII centuries. The main achievement of this construction was the central temple - the largest temple built in the Middle Ages and completely destroyed at the beginning of the XIX century.

This project by architect Manfred Koob (Bensheim, Germany) marks an important step forward in the digital visualization of architecture: using CAD software, an architecturally complex building, of which only ruins remain, was digitally reconstructed for the first time. There has never been a project of this scale before. 7337 individual components were designed and assembled into 320 groups, which made up certain elements of the building. These reconstructions were then combined and provided with surface textures. In October 1989, the project was completed after a construction phase that lasted several weeks: as a result, a four-minute tracking simulation film consisting of 6,000 individual images was shot in virtual Cluny and its surroundings.

The interior component is also present in this reconstruction, but there is no main emphasis on it, there is no filling, materials and textures. Nevertheless, there is a detailed study of the internal structure of the space, which was dictated by relying on drawings and plans in the process of forming the overall architecture of the building (see Fig. 2).

Fig. 2. Virtual 3 D reconstruction of Cluny III: section and rendering of the interior. (https://strabic.fr/Cluny-III-en-3D)

The above-mentioned virtual reconstruction projects were developed as part of joint research by archaeologists and architects. The fundamental approach to working on three-dimensional visualizations of lost architectural monuments from the point of view of archeology (both landscape and exteriors, as well as interiors) was formulated and described in detail in the works of the outstanding archaeologist P. Riley ^{[4, 5, 9, 10]}. He became the founder of the field of "virtual archaeology" (English: virtual archaeology, digital archaeology). These approaches have had a definite impact on the formation of the applied fields of virtual paleoanthropology and "digital history".

It is worth noting that the main focus of research even then in the 1980s was shifted towards the development of methods for forming assumptions and testing them in the context of the general structure of a building or a complex of buildings, which is often associated with the specifics of the source base, which is simply not enough for more detailed study than the location of structural elements (floor, walls, stairs).

The next stage in the development of the topic of virtual interior reconstructions was one of the first attempts to create digital reconstructions of palace interiors as part of the recreation of Dudley Castle in the West Midlands, Great Britain, in the early 1990s ^[11] (http://exrenda.com/dudley /).

Archaeologist Peter Boland and computer artist Colin Johnson reconstructed Dudley Castle, the Renaissance castle of the influential Sir John Dudley, Duke of Northumberland, in a computer model, as it would have looked in the 1540s. This place is also known as Sharrington Range: it was named after the architect Sir William Sharrington, who at that time erected several buildings for the Duke. These buildings are the focus of a 3D model that visualizes both exterior and interior views (see Figure 3).

The reconstruction of the castle was based on measurements of existing ruins, the results of archaeological excavations conducted in the 1980s, as well as on records consisting of historical views and written documents. The historian advised on virtual interior design using antique furniture.

The result of the work was the first interactive viewing installation at the Dudley Castle exhibition, which was designed as a virtual tour. The visitor could follow a set route through the castle, but also had the opportunity to navigate through the computer model at will using three buttons (left, right, forward).

However, Boland and Johnson stressed that their computer reconstruction visualized interpretations and assumptions about the historical appearance of the castle and its interiors and did not reflect the actual state of things. This interactive application developed for the exhibition was one of the first in the field of virtual reality and was used in the exhibition area of the castle until 2005.

Fig. 3. Dudley Castle in the West Midlands: current state and virtual 3 D reconstruction of one of the premises. (http://exrenda.com/dudley/)

One of the largest projects for virtual 3D reconstruction, which included the interiors of architectural structures, was Rome Reborn ("Reborn Rome"), the first results of the development of which were made in the context of academic research in the 1990s (https://www.flyoverzone.com/virtual-tours-2 /). This is a very detailed, comprehensive digital 3D model of the city of Rome, work on which continues to this day. She visualizes the development of the city of Rome between 1000 BC and 550 AD. The project was started in 1995 at the University of California, Los Angeles (UCLA) in the form of an international collaboration of several disciplines such as architecture, history and computer science in the USA, Great Britain and Italy. The aim of this project is to visualize the topography and evolution of Rome, including the interior of its buildings, over a long period of urban development. The first 3D model created under the auspices of this project dates back to 1996 and shows the temple of Antoninus and Faustina.

Since the work on the project has been carried out continuously for decades, several versions have emerged, each of which reflects a different state of knowledge and current research about Ancient Rome, its buildings and interiors. So, there are objects for which the source base is extremely small, therefore, it is necessary to develop various hypotheses and test them in virtual space so that a group of experts can subsequently make their assessment.

The methods of supplying the model with a source base and verifying the results obtained during the reconstruction process in this project not only began to be approved within the framework of the study, but for the first time were reflected in the process of official certification of each specific element of the model, which seems controversial. If the scientific committee of the project was able to classify one specific condition of the model as certified, then future changes can only be made with the consent of the committee.

Separately, we note that at the moment the latest developments concerning interiors have been published within the framework of this project. Of course, these virtual models have a much higher degree of photorealism and allow you to make a full impression of the monuments (see Fig. 4, 5).

As a continuation of the Rome Reborn project, it was extended to the reconstruction of the building and interior decoration of another iconic architectural heritage. It includes monuments from Athens (Greece) (https://www.flyoverzone.com/athens-reborn-acropolis /), Tivoli (Italy) (https://www.flyoverzone.com/hadrians-villa-reborn-stadiumgarden /), Balbec (Lebanon) (https://www.flyoverzone.com/baalbek-reborn-temples /) and others.

Fig. 4: Hadrian's Villa Reborn ("Hadrian's Villa Reborn"): virtual interior renovation (2018) (https://www.flyoverzone.com/hadrians-villa-reborn-stadiumgarden /)

Fig. 5. Rome Reborn: visualization of the interior of the Pantheon (2020) (https://www.flyoverzone.com/rome-reborn-pantheon /)

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The reviewed projects clearly show that, already since the 1980s and even more so in the 1990s, the theme of the interior in the development of virtual 3D reconstructions was of interest to researchers. Nevertheless, the specific methods of working with the source database largely duplicate those applied to the exterior. In this context, it is important to consider another group of works, where researchers focused on non-trivial tasks and ways to solve them specifically in the reconstruction of the interior decoration of premises.

Among the early virtual 3D reconstructions of individual buildings and their interiors, such a project was described in the review by H. Mesemer ^{[7, p.32-34]}. The author of this project, V. Muller, was a pioneer of three-dimensional reconstructions in the field of art studies. Together with mathematician N. Kien, they specialized in creating computer reconstructions of elements of historical architecture. Under the guidance of Professor Dr. W. Jaeger, then head of the Interdisciplinary Center for Scientific Computing (IWR) in Heidelberg, in the early 1990s they created a 3D visualization of the interior, which recreated the design process of late Gothic decorative arches.

The shape of the vault and window profiles were borrowed from the projects of "Stromersches Baumeisterbuch" (Nuremberg, c. 1590), which were test samples for the exam for obtaining a master's certificate and were not intended for real construction.  In the project, the main methods were both traditional complex source analysis and mathematical modeling. The researchers also introduced the method of selecting analogies into their work and performed the floor according to the medieval model (see Fig. 6).

Fig. 6. The late Gothic decorative arches designed by Muller and Kien and their implication in the hypothetical interior of the church. ^{[7, p.32-34]}

One of the examples of solving specific tasks of virtual interior reconstruction based on archaeological research was the development of Czech researchers. It should be noted that the forerunner of the Czech virtual 3D reconstruction were the standards of Czech construction archaeology and approaches to depicting archaeological sites and their reconstructions on a plane.

The first tradition within this school was associated with the works of archaeologist M. Radova ^[12]. Since the 1970s, M. Radova has worked with simple, "transparent" isometric drawings. They were not only supposed to depict the previous appearance, but also to offer a way to explore the internal spatial structure of the building. The researcher has made various attempts to reconstruct stairs and vertical buildings. This tradition of 3D graphic representations has its roots in the school of architectural thinking, which always treats a building as a 3D object.

The second tradition was developed in the 1980s, when archaeologist P. Chotebor proposed a new philosophy of representation of reconstructed buildings: he focused on scale and omitted all private details ^[13].

The synthesis of these two traditions has led to the fact that even when creating reconstructions of buildings in 3D graphics, scientists began to pay more attention to their spatial structure and develop methods of working with it.

Thus, the communications and functions of the rooms inside the building were an important subject of study when creating a virtual 3D reconstruction of the Bishop's Castle of Litovitz. It can serve as an example of various types of room layout distributed over several floors, and how this distribution has changed over time ^[14].

The 3D visualization of a group of houses in the Old City of Prague performed two functions – both as a means of evaluation and as a visual representation - and depicted the structure of the location of three houses combined. An analysis of the boundaries between the buildings led to the discovery that these houses were built from adjacent walls and ceilings (see Fig. 7) ^[15].

Fig. 7. Visualization of the location of the group of houses No. 151-3 in the Old Town of Prague ^[13]

The digital model of the 2000s of the house "At the stone bell" in Prague, which was built at the beginning of the XIV century as the city residence of the royal couple, is an example of a reassessment of what had been achieved earlier in archaeological research on the history of the object. It led to a change in the view of spatial structures on the second floor of the residential tower, in the basement and at the northern portals giving access to the spiral staircase. To develop hypotheses focused on the northern portals leading to the stairs, the main research method was to survey the height using elevation tables. For example, taking into account the spatial position and height, it was found that in the corner between the tower and the west wing there could be a storage chute with three cabinets located on top of each other (see Fig. 8).

Fig. 8. Houses "At the bell" in Prague: section of the tower, spiral staircase and guard rooms (https://www.ghmp.cz/en/buildings/stone-bell-house /)

A unique approach to the study of internal spatial structures was proposed in a study on the visualization of the projects of the Palazzo Rubens (Genoa) for the Antwerp Neustadt of the XVII century by P. Lomberde and M. Muil ^[16]. The authors applied a radical approach to the creative use of experimental digital models for architectural research in order to reveal, among other things, its educational potential. The placement of Italian-style palaces in almost a northern city and the comparison of their plans and architectural features with neighboring buildings of different periods clarifies the reasons for regional building traditions and helps in their assessment.

The symbiosis of light physics and architecture analysis proved to be especially effective. Scientists have found that the intensity of lighting in different latitudes caused differences in the layout of building windows: on average, the window area in Antwerp was three to four times larger than that of the Genoese. It was also established that the ratio of height and width of windows in Antwerp decreases with each floor (the tallest windows on the ground floor), while in Genoa this ratio increases to the upper floor (see Fig. 9).

In the context of this approach to the virtual 3D reconstruction of the historical interior, we note the work of the Russian researcher A.M. Lidov, the author of the concept of hierotopia - the science of creating sacred spaces ^[17]. The historian and art theorist, specializing in the history of Byzantium, paid much attention to the study of the problems of light as one of the most important means in creating sacred spaces, creating the basis for the possible application of his research methods in reconstructions of the interior of temple buildings.

Fig. 9. Comparison of the difference in light intensity for a palazzo between a Genoese freestanding structure and an Antwerp terraced structure ^{[16, p. 112]}

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The development of computer technology over the past two decades has led to the fact that gradually researchers began to pay more and more attention to the marked differentiation in approaches to virtual 3D reconstructions.

D. Lengyel and E. Tuluzskaya identify two main types of three-dimensional reconstructions of cultural heritage sites:

1. Didactic models – models that identify uncertainties and gaps in knowledge about a particular object;

2.                     Complete models are models that show all elements with the same level of detail and create the illusion of completeness ^[18].

This classification is especially relevant for research on interior topics, since interior reconstructions, as a rule, require very detailed and voluminous data. Nevertheless, now, taking into account the specifics of the source base and research tasks, it is possible to reasonably choose a didactic or complete approach and methodologically and technically build a study in accordance with them.

From M. Grellert's point of view, the didactic approach is recognized by the research community as more scientific, because among the tasks of such a virtual reconstruction there is no topic of creating atmospheric and immersive visualization. Meanwhile, complete models are much more popular due to their imagery, and therefore often become the main exhibits of exhibitions ^[19]. M. Grellert made an attempt to propose methods of work in the context of such complete reconstructions that would allow transmitting not only a full-fledged image of a cultural monument, but also effectively coped with the tasks of knowledge transfer and were less susceptible criticism from archaeologists, historians, art historians and architects.

As part of the work on two large projects on virtual 3D reconstruction, which were carried out at the University of Darmstadt in Germany, M. Grellert was able to identify several approaches to such tasks, including in interior design. The first project, started back in 1995, was a virtual reconstruction of synagogues destroyed by the Nazis in the 1940s: synagogues of Berlin, Dresden, Hanover, Cologne and other cities were restored in the form of three-dimensional graphics ^[20] (see Fig. 10).

10. The Darmstadt project for the virtual reconstruction of synagogue interiors with various source bases (renderings 2002-2008). ( https://www.dg.architektur.tu-darmstadt.de/forschung_ddu/digitale_rekonstruktion_ddu/synagogen/index.de.jsp)

The second project was a virtual reconstruction of the Dresden Castle in 1678 ^[21].  The main result of this work at the moment includes a virtual tour of the streets, courtyards and selected interiors of the former presidential palace for one time slice (see Fig. 11).

Fig. 11. Details of the virtual reconstruction of the interiors of the Dresden Castle in 1678 ^{[21, p. 135]}

The main problem that comes to the fore when creating such reconstructions is that the principle of historicism of the research methodology and the principles of creating photorealistic graphics begin to contradict each other. Grellert notes that the more realistic the models created, the more realistic the facts on which they are based should be reflected. Thus, there is a special responsibility to overcome such problems in a scientifically sound way. Reconstruction should correspond to the orientation towards a reliable reproduction of a possible historical reality ^[19].

Using the example of the above two projects of the University of Darmstadt, M. Grellert deduces several strategies that can fill in the gaps in the source base when creating a complete virtual 3D reconstruction, including the interior decoration of historical buildings:

1. Filling in the gaps by adding fragments and retouching;

2. Filling in the gaps with the composition of the complemented fragments;

3. Filling in the gaps with analogies and copying;

4. Filling in the gaps using abstraction ^[19].

Grellert also proposed a protocol for documenting the reconstruction process and ways to verify knowledge, which still remains one of the main problems when creating virtual 3D reconstructions ^[20].

Another important trend in virtual 3D reconstructions in recent years has been the growing demand for virtual reality (VR) and augmented reality (AR) technologies ^[22]. Of course, already in the above-described project of virtual 3D reconstruction of Dudley Castle in the West Midlands, Great Britain, created in 2005, the first applications were implemented to immerse museum visitors into the virtual space of the monument's interiors (http://exrenda.com/dudley /). Nevertheless, it was an innovative project, and the technology was not widely used at that time.

With the development of the computer game industry, more and more convenient programs began to appear, which made it possible to develop 4D solutions for visualization and presentation of virtual reconstruction projects, including historical interiors ^[23].

Thus, within the framework of the Rome Reborn project, many models of reconstructed buildings and their interiors began to be accompanied by interactive solutions that are not inferior in image quality to high-quality renderers and make it possible to explore the historical interior and feel its atmosphere with the help of virtual reality (see Fig. 12).

Figure 12. Rome Reborn Project: Using virtual Reality technologies for virtual tours of the Basilica of Maxentius (2018) (https://www.flyoverzone.com/rome-reborn-basilica-of-maxentius )

Another innovative project was the creation of interactive virtual 3D reconstructions in the Internet space using special technology Second Life (from English - "second life") - a three—dimensional virtual world with elements of a social network, which has more than 1 million. active users. An interactive open source project by Alexandra Gago da Camara, Helena Moreira and Paulo Rodriguez is dedicated to the reconstruction of Lisbon, which existed before the earthquake on November 1, 1755. The authors created this project as a laboratory model for studying the history of the city (https://lisbon-pre-1755-earthquake.org /).

The starting point of the project is a virtual recreation of one of the most symbolic spaces of 18th century Lisbon - the Royal Opera House. Using Second Life technology, it was possible to create a model of both the structure and interiors of the Opera House, as well as its animation in combination with a small fragment of the opera presented at the grand opening of the building in April 1755 (see Fig. 13).

The team of scientists, as well as researchers from the University of Darmstadt, paid great attention to the source base and ways to present it in open access to visitors within the framework of the model.

The fact is that the availability of primary and secondary sources online corresponds to principle No. 4 of the London Charter for Computer Visualization of Cultural Heritage (http://www.londoncharter.org/downloads.html ), which states the need to document and disseminate information used in virtual reconstructions in such a way that the procedures used and the results obtained can be understood by users and evaluated depending on the context and the purposes for which they were designed. It also emphasizes the need to register all analytical, deductive, interpretative and creative assessment procedures performed in the construction of virtual models.

Fig. 13. Virtual reconstruction of the interior of the Royal Opera House of Lisbon in the Second Life Internet space. (https://lisbon-pre-1755-earthquake.org /)

Many museums actively use new opportunities to present their developments in the field of three-dimensional reconstructions. The use of dynamic three-dimensional models and augmented and virtual reality are now one of the most promising areas in the development of museum business. For example, the staff of the "Virtual Museum of Everyday Life" (MUVI, Italy), carried out a reconstruction of the Bologna everyday life on three time slices: the 1930s, 1950s, 1980s. Each section corresponds to a 4D reconstruction model, which includes the development of the Bologna quarter with exteriors and partially restored interiors. The source base of the study consists of photographs of different times. The presentation of the project involves the possibility of a virtual visit to the museum (http://muvi.cineca.it /).

Large companies are also attracted by the topic of virtual 3D reconstruction of architectural monuments, as it provides an opportunity not only to act as a partner in scientific research, but also to demonstrate their developments. The most striking project of this kind is the virtual reconstruction of the exteriors and interiors of Versailles, which was carried out by Google in collaboration with the museum: the decoration of the palace and park complex was recreated on five time slices: 1624, 1668, 1679, 1725 and 2012. The site provides an opportunity to inspect the reconstructions by watching videos, virtual visits to the buildings of Versailles of different times, the possibility of virtual immersion in space in 360 video format (http://www.versailles3d.com/en /).

The main disadvantages that are present in projects like the two mentioned above are the opacity of the source database development process. Research users cannot trace which materials were used in the reconstruction, how the comparative analysis took place, etc., therefore, the scientific community perceives them more as free representations than justified historical virtual reconstructions.

* * *

The domestic experience in researching the methodology of creating virtual 3D reconstructions of architectural monuments is quite extensive.

The basic methodological works that reveal the methods of mathematical modeling in history, which include 3D reconstructions, are the work "Methods of Historical Research" by I. D. Kovalchenko ^[24] and the monograph by L. I. Borodkin "Modeling historical processes: from reconstruction of reality to analysis of alternatives" ^[25]. These papers present the most complete classification of historical research methods and models of historical processes and phenomena, which is useful for determining the place of 3D technologies in this context.

A detailed description of the main stages of historical 3D reconstruction is contained in the article by D. I. Zherebyatyev. Using the example of the monastery complex of the Moscow Convent of All Sorrowful Joys, the researcher implements in practice the following stages of recreating the lost monument:

1.                     Setting the task of historical reconstruction

2.                     Determination of the range of available graphic, pictorial and descriptive sources, i.e. the formation of a source base on the basis of which the construction of three-dimensional models will take place

3.                     The choice of the software necessary for the implementation of the tasks

4.                     Verification of the source database

5.                     Construction of three-dimensional models of the studied historical and cultural object

6.                     Building an interactive user navigation system in three-dimensional space and ensuring verification of 3D model elements ^[26].

The last stage is innovative, including the possibility of immersive immersion of the user into the recreated reality of the past.

It is important to note that the creation of historical scientific reconstructions of cultural monuments, including computer reconstructions, as part of the work on the history of architecture and scientific research has been actively practiced since the early 2000s at the Moscow Architectural Institute (MARKHI) on the basis of the Department of the History of Architecture and Urban Planning under the leadership of S. V. Klimenko, D.A. Karelin, Yu.G. Klimenko. In their research, scientists pay attention to the problems of the spatial structure of the interior of buildings, important aspects of working with perspective, methods of visualization and transmission of lighting. ^[27]

Among the few Russian historical works devoted to the virtual reconstruction of lost interiors, we highlight the 3D reconstruction of the refectory of the Feodorovsky town in Tsarskoye Selo ^[28], as well as projects carried out at the Department of Historical Informatics of the Historical Faculty of Moscow State University:

- virtual reconstruction of the interior of the Church of the All-Merciful Savior of the Sorrowful Monastery in Moscow at the beginning of the XX century (https://xn--e1adhj9a.xn--80adj2apjcc.xn--p1ai/2022/11/10/%D0%B8%D0%BD%D1%82%D0%B5%D1%80%D1%8C%D0%B5%D1%80-%D1%81%D0%BE%D0%B1%D0%BE%D1%80%D0%B0-%D0%B2%D1%81%D0%B5%D0%BC%D0%B8%D0%BB%D0%BE%D1%81%D1%82%D0%B8%D0%B2%D0%BE%D0%B3%D0%BE-%D1%81%D0%BF%D0%B0%D1%81/);

- virtual reconstruction of the Small (Lower) Office of Emperor Nicholas I in the Winter Palace in 1850-1855 (see Fig. 14) ^[29];

- virtual reconstruction of the interiors of estates near Moscow of the XVIII – early XX centuries on the example of the ceremonial interiors of the Nikolskoye-Uryupino estate complex (see Fig. 15, 16) ^[30].

Fig. 14. Virtual 3D reconstruction of the Small (Lower) Office of Emperor Nicholas I in the Winter Palace in 1850-1855 (https://e-notabene.ru/istinf/article_30086.html ?ysclid=lvdy943gim527665905 )

Fig. 15. Virtual 3D reconstruction of the interiors of the Nikolskoye-Uryupino estate complex: White House (https://e-notabene.ru/istinf/article_36029.html ?ysclid=lvdx8sulst902294752)

Fig. 16. Virtual 3D reconstruction of the interiors of the Nikolskoye-Uryupino estate complex: White House (https://e-notabene.ru/istinf/article_36029.html ?ysclid=lvdx8sulst902294752)

In domestic interior reconstructions, there is a search for new forms of methodological and technological solutions within the framework of virtual reconstructions, while the degree of study of the experience of foreign researchers, both predecessors and contemporaries, seems insufficient.

Conclusion

Thus, at first glance, the direction of interior virtual 3D reconstructions in historiography is significantly weaker than numerous projects of virtual reconstructions of architectural complexes and their exteriors, as well as landscapes. Nevertheless, many projects include reconstructions of selected interiors as components necessary to create a full-fledged visualization of historical monuments.

As a result of three decades of development of the problems of virtual reconstruction in relation to the historical interior, two main areas of research have been formed in foreign historiography – the development of didactic and complete virtual reconstructions, as well as the evolution of approaches to working with the source base and creating visualization of its results is everywhere observed. Especially important for interior themes is the increase in the degree of photorealism, the use of the possibilities of virtual 4D reconstruction, the implementation of the results into museum practice and the creation of interactive online presentation platforms.

Today, there is still no single standard for virtual 3D reconstruction, especially when it comes to the interior, so the analysis of research experience provides a methodological foundation on the basis of which it is possible to create a modern study that meets the needs of both the scientific community and the sophisticated user.

The developments of the author of this article on the topic of virtual reconstructions of manor interiors seem relevant in this context both in methodological terms and in practical terms. Especially important here is the task of reconciling the concept of a full-fledged reconstruction model using the latest computer technologies and the need for scientific justification of each specific fragment of the model, i.e. the transfer of the image and feeling of a "living" historical interior and the rigor of a disciplinary approach.