Martin Langner, Introduction to Digital Image and Artefact Science (Summer Semester 2021) IV Presentation: Lesson 11. Reconstruction, Simulation and Virtual Reality (https://youtu.be/yZ4a8-JrCAg) [1] Introduction [2] Types of documentation, reconstruction and simulation [17] Content of the lesson [17] 1. Virtual Reality [21] VR Environments [29] Cyberspace, Augmented and Mixed Reality [32] Technologies and fields of application [39] 2. Strategies, methods and standards of digital implementation [41] Implementation [44] Aims and Methods [45] Visualisation of Uncertainty [50] Research sources [53] Documentation [68] 3. Examples of digital modelling of space and time [57] Virtual Museums: History [80] 4D Reconstruction (Ename / Belgium) [96] Reconstruction from the 3D Printer [104] Conclusion [104] Current research questions [105] What you know and what you should be able to do [108] Literature 1] I would like to welcome you to the eleventh lesson of the lecture "Introduction to Digital Image and Artefact Science". We have already reached the fourth section of our lecture, which is about the digital presentation of research results. In the last lesson we had already talked about data visualisation. Today we will focus on the digital reconstruction and simulation of cultural heritage sites. The creation of a virtual reality plays a central role in this. The field of virtual museums, augmented reality and gamification will interest us in the next session when it comes to the digital mediation of humanities content. 2] At the beginning of every reconstruction is the graphic documentation of what is preserved. As a method of historical building research, it is very old, because since the Renaissance at the latest, architects have taken the buildings of antiquity as a model and made accurate drawings of them for use in their own designs and complemented them to make up complete building structures. Or they tried to capture the atmosphere of the ensemble of ruins, sometimes in romantic transfiguration, and therefore attached particular importance to the destroyed parts. 3] From these, straightened sections, exterior views and ground plans develop, which, like the architect's design drawings, are intended to document the original construction and planning process. They thus reflect the function and structure of a building and serve to check reconstructions for their plausibility. With such drawings, the interrelationships and proportions of the individual building elements become clear, which could of course also be visualised three-dimensionally and interactively. 4] A less exact approach is taken in drawing reconstruction, which is usually concerned with restoring the overall impression. Here, a sketch-like visualisation is often chosen to indicate that it is a possible reconstruction (among others), in which some details had to be added. 5] The graphic illusion is even further detached from the documented situation. It is used in functional graphics and diagrams or in artistic renderings. [6] Related to this are (interactive) explanatory graphics for schools or museums, which are intended to convey structural factual knowledge in a vivid way. In this case, attention to detail is dispensed with in favour of better comprehensibility. 7] This experience of space and its effect are in the foreground of virtual panoramas, which allow a panoramic view from a fixed vantage point. After its great success in the 19th century, the panorama as a view of the world is once again enjoying great popularity. But not only as a museum presentation, as in Yadegar Asisi's panoramas, but also in CD-ROM and internet-based presentations. 8] In (virtual) object panoramas, the object being viewed is in the centre of the viewer's gaze. He can move freely around the object and view it from all sides. Such models are just as popular as exhibition objects as they are as 360° photo series on the Internet. Here, too, vividness is required, although the illusion does not necessarily have to be photo-realistic. 9] Digital methods are now also used in the construction of such models by printing out the model created in a CAD programme with a 3D printer. The advantage of this method is obvious: once created, models can be printed again and again, and of course a scientific comparison of these models is technically possible. 3D models keep their shape constantly, can be replicated, but are flexible in terms of corrections and extensions. [10] A very different form of reconstruction is physical reconstruction on the building itself, which is often referred to as restoration. It is not uncommon for this to involve the removal of fixtures and additions, so that what emerges as a reconstruction is a cleaned-up ruin that is also only loosely related to the original building. [11] The topographies of terrain models and exact building construction are usually created with precise CAD programmes. They therefore always appear somewhat sterile and unreal, because traces of weathering, slight differences in materials and indications of the building's use are missing. [12] These shortcomings are compensated by the more elaborate 3D modelling, because irregularly and organically shaped bodies as well as the design of surface, light and movement can be created much better with special 3D animation programs such as Blender. Here, the form is modelled less by the line and more by textures, materials and light incidence. 13] Such 3D models of buildings and entire cities can of course also be animated. Computer games and 3D levels that can be walked through virtually find their place in 3D real-time applications and thus create the impression in the viewer's mind of being in front of or inside the real building. [14] Particularly in the case of historic buildings, the source material is often poor, so that one has to rely on simulating the appearance of the buildings and the processes of their use. For experts, however, the advantage of such simulations is that they can be used to check the plausibility of the reconstruction and to propose optional solution models. And in the gaming sector, simulations can be used to convey learning content in an unobtrusive, entertaining and playful way. The scientific content is thus by no means neglected, but is methodically and didactically prepared in a valuable way. 15] For visitors to the ruin sites or tourist centres, these reconstructions and simulations can be virtually pushed in front of the visual axis with a handheld device. The area that the camera acquires is enriched with the model, so that one also speaks of augmented reality. 16] Depending on the purpose, one or the other type of documentation, reconstruction and simulation will be used. I have briefly explained the advantages and disadvantages and once again present the possibilities presented on an axis between exactness and complete illusion. 17] Of these, virtual reconstruction will interest us most today. Accordingly, this lesson again breaks down into three parts. First, we will deal with the technical aspects of virtual reality, taking an interest in the possibilities of hardware and software and the resulting requirements. In the second part, I will explain strategies, methods and standards of digital implementation as described in the London Charter. I will conclude this lesson with a few examples of digital modelling of space and time. [18] Let's start with the definition of virtual reality and the technology associated with it. [19] If one understands 'virtual' in the original sense of the word as 'possible' or better 'existing as a possibility according to its setting', i.e. as something that is not present in reality but appears real, then the architectural illusions of the Pompeian wall painting also create virtual spaces. Accordingly, the term 'virtual reality' is also commonly understood very broadly, as a simulated representation and simultaneous perception of a reality that can be similar to the real world. 20] Virtual reality is also used as a generic term for all kinds of computer-generated worlds. However, we want to define Virtual Reality more precisely as an immersive, computer-simulated reality that creates a physical environment that does not exist and is independent of the users' current physical reality. Users are thus transported into a computer-generated, interactive 3D environment that they perceive in real time and that seems real to them. [21] An important aspect of virtual reality is the possibility of immersing oneself in the computer-simulated world and becoming part of it. Virtual environments therefore extend the representation on a display by allowing the user to interact with the virtual world. For example, using VR glasses, they can acquire the user's head movement and react to it with appropriate visualisations in real time, further enhancing the impression of reality. [22] Concerning the hardware, such VR environments can consist of large screens, as you know them from public viewing. As with the panorama, the projection surface can consist of a mostly circular room onto which moving images are projected with several beamers, creating a three-dimensional illusion. The Max Planck Society here in Göttingen, for example, has developed such a CAVE with its Datarama. In contrast to head-mounted displays, a CAVE offers several users the opportunity to experience a virtual world together at the same time. In the meantime, however, head-mounted displays, i.e. video or VR glasses, have become established, with which disruptive environmental influences can be significantly minimised. [23] Virtual environments should therefore have a maximum of plausibility and interactivity. That is, interaction in the virtual world should be consistent and coherent. This requires that actions such as a turn of the user's head have an influence on the virtual environment. At the same time, his action has an effect on him, because the events in the environment of the focused person in turn stimulate his senses. This double interactivity creates the illusion of real events. [24] The forms of interaction are not limited to head-mounted displays, however, but enable complete physical movement through the virtual world. To this end, a number of special input devices such as 3D mice, data gloves or omnidirectional treadmills are currently being developed, with which objects can be touched, moved and manipulated. 25] Besides plausibility and interactivity, the success of a VR environment stands and falls with its fidelity. If the virtual world reproduces characteristics of a natural world, it appears credible to the user. Fidelity does not necessarily mean hyper-realistic modelling. Comic-like worlds can also be convincing. The decisive factor is that they are rendered uniformly and coherently. Force feedback on the hands or other parts of the body creates realistic simulations in the three-dimensional world through haptics and sensorics as a further sensory sensation, which also increase interactivity and fidelity. [26] A key concept here is immersion, i.e. the embedding of the user in the virtual world by reducing self-perception in the real world. It is about the feeling of being surrounded by a completely different reality that draws the user's entire attention and has a direct influence on his or her perception and actions. As a vision of the future, you may know the holodeck of the Star Trek series. This is a "space that can create any environment audiovisually, haptically and [...] also olfactorily and gustatorily." [27] According to Richard Bartle's four levels of immersion, the user of VR environments is involved to different degrees. As a player, she or he only influences virtual reality via a predefined game character. As an avatar, the user possesses a representative of himself in virtual reality, but without merging his identity with it. As a rule, users still speak about the character in the third person. At the next stage, the user identifies himself with the avatar and speaks about this character in the first person. This can go so far that the avatar becomes part of the user's identity and is absorbed into him. Now he is not playing a character in a virtual world, he is in it himself. Many computer games aim to merge the player with the character, which is why there are always warnings about the personality-altering dangers of computer games. [28] This complete immersion in a virtual reality is also not without health problems for people: if, for example, artificial and actual movement and acceleration diverge, dizziness (so-called motion sickness) occurs. It can also be difficult and time-consuming to return to normal reality and find one's way around again if one was too emotionally involved. 29] If several users appear in a common virtual environment, this is also referred to as cyberspace. Such internet-based 3D infrastructures (also called Web3D) overcome spatial distance and allow users to interact who would perhaps not meet in real life. Second Life by Linden Lab or Hubs by Mozilla are perhaps the best-known platforms, but cyberspaces are also increasingly used in school education. [30] Augmented reality augments the user's physical reality, which they see directly or on a display in front of them, with computer-generated input such as still images, audio or video. Thus, no new reality is created, but the computer-generated content lies as an overlay on top of the real content. However, the two environments have no way of communicating or reacting to each other. Augmented reality is often used to illustrate reconstructions of archaeological sites or monuments on site in a city tour. [31] Strictly speaking, interaction between the real world and digitally augmented content only takes place in so-called "mixed reality". Here, digital content appears and behaves as if it existed in physical space and was part of the real world. Mixed reality thus integrates computer-generated content into the real world so that digital and real world can interact with each other. As with Virtual Reality, this can be a completely digital environment that is connected to real world objects, such as when your hands are superimposed into the Virtual World. Sometimes this is called augmented virtuality or merged reality. Or, conversely, it can be the real environment (as in Augmented Reality) reacting to digital content. You probably know the latter from Pokemon Go or similar games. Since the transitions between augmented reality and mixed reality are fluid, the term is increasingly being used in general for any combination of analogue and digital reality. As an umbrella term for AR, VR and MR, there is now more and more talk of "extended reality". Since Intel, Google, Facebook, Microsoft and Apple, among others, are working on their own products, it is to be feared that a few more new terms will appear in the next few years for marketing reasons. For scientific purposes, however, it is important to use clearly defined terms. This also applies to technical aids, which we will also briefly discuss. 32] The best-known kind of head-mounted display is the virtual reality headset, a pair of video goggles that also has sensors to detect movement of the head. The commercially available headsets consist of one or two small displays with lenses and semi-transparent mirrors built into a pair of data glasses. Due to the spatial proximity to the eye, the image areas of headsets appear much larger than those of stand-alone displays and usually cover the user's entire field of vision, which at around 100°-110° is, however, smaller than that of human vision (180°). Like the human eye, virtual reality headsets use stereovision to create depth of space by showing a slightly different image to each eye. The area that is common to both eyes is the basis for spatial perception and distance estimation. This area is also called binocular overlap. In humans, the binocular overlap is about 100° (50° left of the nose and 50° right). For virtual reality headsets, 75° is already a good value (which is sometimes also given as a percentage). [33] Augmented reality glasses are smartglasses that project information onto the lenses and thus directly into the wearer's field of vision. This can be internet pages, as with Google Glass, or "holograms", i.e. 3D graphics, as with Microsoft HoloLens. However, smartglasses are not allowed in public areas. Since, for example, with Google Glass a photo can be taken by the mere blink of an eye and evaluated with facial recognition software, the use of smartglasses in public spaces is classified as unlawful video surveillance. 34] A number of technologies are used for control. In addition to buttons, touch pads or smartphones, voice and gesture control or eye tracking are also possible. In the VR sector, however, input devices with motion sensors seem to be the most popular, either in the form of a wired data glove or as a controller that wraps around the hand like a degen grip. In addition to a posture that is as natural as possible and intuitive operation, the focus here is also on responsiveness. Newer controllers also address the sense of touch through finger touch recognition and haptic feedback, simulating the weight and resistance of virtual objects. [35] Virtual reality simulators, which can even convincingly convey the feeling of flying through the air, demand the whole body. [36] Of course, this is not possible without suitable software that is capable of calculating at least 25 images per second in real time and in stereo (separately for the left and right eye) and projecting them onto the display (a driving simulation even requires at least 60 images per second). Widely used programmes for 3D modelling are e.g. blender, for which we offer exercises every year, but also Maya, 3D Studio Max, SketchUp, Cinema 4D, or LightWave 3D. And for interactive simulations, one uses game engines such as unity3D or authoring systems such as World Tool Kit or World Up. [37] And the computer language VRML/X3D and the JavaScript API WebVR are used to display multi-user, interactive, graphical 3D simulations on the internet. [38] Virtual reality has long been used not only in the film and gaming sector, but also, for example, in pilot training, vehicle development or occupational safety. Spatial VR simulations have now also become standard in spatial planning, in the advertising and real estate industries, in virtual online shops or virtual exhibitions and, of course, in the simulation and reconstruction of historical places. [39] As a result of the technical effort and widespread use of VR applications, scientific accuracy has fallen somewhat behind. In the second part, we therefore want to discuss some strategies, methods and standards of digital realisation, which have already been laid down in the second version of the London Charter since 2009. 40] The London Charter for the Computer-Aided Visualisation of Cultural Heritage sets out internationally recognised principles for the use of computer-aided visualisation by academia, teaching institutions and cultural institutions. The specific requirements of virtual archaeology were concretised in the "Seville Principles" in 2010. Since then, workshops and conferences have been held regularly to discuss the rules and keep them up to date. [41] Films such as Jurassic Park make the boundary between present, past and future permeable. In their high degree of realistic visualisation, the viewer can no longer distinguish what is authentic about the dinosaurs and what belongs to the realm of fantasy. Are such visualisations credible interpretations of history or simply beautiful images of the past? A particular challenge with all computer generated images is therefore to consider exactly what is to be seen and how it could be understood. [42] This is why the first guiding principle of the London Charter requires that computer-generated visualisation methods be applied in a strictly scientific manner: Research sources, tacit knowledge and explicit conclusions as well as visualisation-based results are to be strictly separated! In the building survey of the Baths of Caracalla in Rome, for example, the reconstruction as a straightened elevation drawing is superimposed on the graphic documentation of the building stock. The research source here is the preserved ruin and implicit knowledge arises, for example, from the position of the passages or the still preserved ceiling height on the ground floor. Explicit conclusions concern, for example, the colonades, which are statically necessary, while visualisation-based results may be present in the wooden parapet on the upper floor. However, the latter is not specifically expressed in the drawing. [43] These problems arise especially in 3D visualisation, where details have to be reconstructed, supplemented and added to a much greater extent. For some things, better solutions may be found later or hitherto unknown sources may emerge. “Computational models are better understood as temporary states in a process of coming to know, rather than fixed structures of knowledge”, as Anna Bentkowska-Kafel correctly states. [44] The specification of sources goes hand in hand with the specification of aims and methods. Guiding Principle 2 of the London Charter therefore requires: "It should be made clear to users what a computer-assisted visualisation aims to represent, for example, the existing condition, an evidence-based restoration, or a hypothetical reconstruction of a cultural object or site as a whole, and of what nature and to what extent any factual uncertainty is." [45] To indicate of what kind and to what extent any factual uncertainty is, there are a number of established methods: Firstly, one could offer an annotated visualisation for each reconstruction, making the fundamentals accessible, e.g. in a pop-up window. [46] On the other hand, as in the case of the Caracalla Baths, the visualisation of a historical state could be superimposed on the present state in transparent 3D models, thus precisely separating existing and reconstruction. [47] In our EsteVirtuell project, everything that is no longer preserved is rendered in a medium shade of grey, while the objects that still exist appear in colour. [48] Another possibility is to visualise uncertainty through line drawings. [49] Uncertainty in detail can also be represented by geometric simplification, which is particularly evident in contrast to geometrically more detailed building elements. [50] Guiding principle 3 is about research sources. It states that research results must be accurately communicated to the user: the state of the art, the differences between evidence and hypothesis, and between different levels of probability must be appropriately identified. [51] In the case of competing hypotheses, for example, one could create two models and juxtapose them in direct comparison or superimpose them alternately. [52] "Particular attention should be given to the way in which visual sources may be affected by ideological, historical, social, religious and aesthetic and other such factors." The reconstruction drawing of the Baths of Caracalla on the left, for example, is primarily concerned with the enormous size and splendour of the thermal complex. It was created at a time when the exemplary nature of antiquity was still beyond question. The added groups of people seem tiny and the colourful design emphasises the unique decoration with coloured marble. The drawing on the right, on the other hand, which comes from an archaeological textbook, aims to present the architectural form as soberly as possible, with plastered or clad brick walls partly left open and walls in the foreground only visible in plan. And the perspective is chosen in such a way that as many details as possible can be made out. In this respect, guiding principle 2 is well implemented here. As a source for a virtual reconstruction, however, one must be aware of this circumstance. 53] The fourth guiding principle concerns documentation. It demands that procedural data (or paradata) should be an integral part of visualisation practice. This means that all decisions made during the creation process must also be documented. "Paradata differs from metadata in that it does not describe the object or artefact that you see, but the human processes by which it came into being." [54] This includes, first, the systematic, documented assessment of the suitability of any method with respect to the goal and, second, the assessment of the nature of the methods used, and secondly, the evaluation of the type of visualisation. Is it more or less photorealistic, impressionistic or schematic? Are hypotheses (or even existing evidence) presented as such? Is the visualisation dynamic or static? etc. [55] The third question is: Which research sources must be used and thus also documented? It is best to collect these in a database from the beginning and finally make them available as well. 56] As an example, I would like to mention the EU-funded project 3D-Icons, where all research sources have been made available online. 57] Another good practice example is the Digital Hadrian's Villa Project, which was implemented between 2007 and 2012, and which not only publishes the 3D visualisation of the villa, but also all the paradata, starting with the goals, a bibliography, the sources and the possibility of contacting ... [58], paradata on each individual building ... [59] to choices of individual complexes ... [60] which were described and also documented as photos and 360° photo series. [61] and the sculpted components are catalogued in a separate database. 62] The Villa Hadriana project has demonstrated quite nicely how paradata could be made accessible. The 3D-ICONS Guidelines specified this process of selection and assessment, acquisition, processing and post- processing, data management and commercialisation in detail according to input, process, person and output respectively, which can still be used as a practicable guide today. [63] These guidelines were further developed as an object-oriented data model in the follow-up project CARARE, so that the data were also semantically processed and made machine-readable. [64] Building on this, Sander Münster and colleagues developed A classification model for digital 3D reconstruction in the context of humanities research in order to establish corresponding norm data. [65] This list is also suitable as a guideline for the documentation of paradata, because in the zeal of modelling, documentation is often neglected. [66] Yet documentation strategies should actively improve visualisation activities. Document all sources (models, images and literature) you have used! Make clear all uncertainties and the degree of accuracy! In our Hippiasbad project, for example, sources of very different weight were used because students used visualisations and reconstructions from children's books and guidebooks in addition to photos of the original inventory. This is perfectly permissible as long as the sources of inspiration are identified as such. For often one is not the first to rack one's brains over constructive details. [67] In summary, the following points can be named that make for good documentation: Make rigorous, comparative analyses and evaluations of computer-aided visualisations possible. Specify which state is represented. And give a complete list of research sources used. Please do not underestimate the documentation of processes (i.e. paradata) either and document your evaluative, analytical, deductive, interpretive and creative decisions comprehensively. Also document and justify the chosen visualisation method, the linking of dependencies and the formats and standards used. Always consider where and how you want to document what! [68] In the third part, we will look at some more examples of how historical facts in space and time can be implemented virtually. [69] A very simple approach is to create a room whose wall surfaces serve as supports for the actual artworks to be presented. Such virtual galleries can now be found in large numbers on the internet. The production is relatively simple, but unlike a list of works that can be scrolled down, it gives the impression of a visit to a gallery, not least because the formats of the paintings stand out better in comparison. In addition, there is the illusion of a room in which the paintings find their place and are not isolated, but contextualised and provided with information panels, thus acquiring the status of a museum work of art. 70] Such musealisations of art have a long tradition. For example, the Habsburg Archduke Leopold Wilhelm of Austria had his art collection, full of collector's pride, immortalised in a kind of gallery, and paintings such as Louis Preusser's give an insight into the Dresden Gemäldegalerie. In a similar way, architectural prospectuses in ancient Roman wall paintings already suggest a visit to a pinacotheca, where precious works of art appear that are, after all, only painted on. Such visualisations come very close to virtual museums, because they do not reproduce real rooms, but convey the illusion of a place that is, in this case, sacred, with ancient folding panel paintings and erected statues standing on bases. [71] Correspondingly, paintings also appear in the pictures of the Archduke's Collection that Leopold Wilhelm can be shown not to have possessed. The character of illusion was, of course, taken to extremes with the ceiling paintings of the Baroque period, which deceptively reproduce cornices, domes and window openings. Long before the first computer-generated views of space, there was already a need to create parallel worlds that do not exist in reality but are conceived as possible. In our definition, however, we cannot yet speak of virtual reality, but only of precursors. 72] An early form of the virtual museum was the "Dresden Gallery" in Second Life, which was an exact replica of the Dresden Picture Gallery and has since been taken down. It tried to simulate the visitor experience, with seating and buttons for explanations via 'audio guide'. [73] And quite successfully: by the end of 2009, the 'Dresden Gallery' in Second Life was visited by 60,000 users a year, which is about 10% of the annual visitors to the Gemäldegalerie, which has 500,000 visitors a year. The visitors in Second Life spent an average of 40 minutes in the "Dresden Gallery". By comparison, the average stay in the real gallery at the time was 45 minutes. 74] The gallery was entered via a realistic replica of the Zwinger. Entering a virtual space in a way that mimics reality is an important aspect of creating a realistic illusion, because it contextualises the simulation. [75] The same applies to doors and passages, level differences and room alignments. [76] However, virtual rooms also offer possibilities that one does not have in real rooms as a human being, such as the view from a highly elevated perspective. [77] or the conversation with people from the past, even if here it is more likely that an avatar appears in front of the user as a visitor guide in a rococo costume. This visualisation dates from 2006 to 2008 and also looks like this. This is because you all have a certain idea of the appearance of virtual spaces ... [78] ... from computer games. And one of the first virtual museums was also developed on a computer game platform and designed as a game. The presentation said: "We present MUSEUM, a fully modelled natural history museum. This 3D world is an interactive level for Counter-Strike, currently the most popular online computer game." [79] Virtual spaces are relatively easy to develop yourself in rudimentary form. With SketchUp, for example, it can be done in 5 minutes. And as I said, we offer a blender course every other semester where you learn how to model. But design and aesthetic criteria are also the subject of discussion in seminars. And with this example, there would certainly be some need. [80] Let me go into a little more detail about an example that I find exemplary. It is about the visualisation of the history of Ename, a small village on the Scheldt near Oundenaarde. The excavation, museum and time scope have been awarded many prizes, and the virtual 4D reconstruction has been EU-funded for many years. 81] Ename is described as the most important settlement in the Duchy of Lorraine at the beginning of the 11th century. However, after Baudouin IV, Count of Flanders, captured and destroyed the fortified castle of Ename, his son Baudouin V completely rebuilt the place. [82] In order to remove any military significance from it, his wife founded a Benedictine abbey there, which was built on the remains of the former border town. [83] The increasing prosperity of the abbey led to the construction of a large Romanesque church for Saint Salvator in the 12th century. [84] In the following centuries, Ename Abbey remained the centre of life in the village. Farmers and craftsmen settled around the abbey and enjoyed a certain prosperity from working for it. [85] The occupation of Oudenaarde by the Protestant troops of the city of Ghent in 1578 was disastrous for the abbey. The monks had to flee and the abbey buildings were looted. Their ruins were used as a quarry until the monks returned. [86] Immediately with the return of the monks, the reconstruction of the abbey began. During the 17th century, the abbey was very rich and had majestic-looking buildings. [87] ... from which a closed complex developed in the 18th century. As you have already seen from the example, such 3D reconstructions are tools for vividly telling history and stories. The facts are thus given a narrative. But the representation of a development also serves to gain knowledge. For some details were only dealt with in the course of the digital realisation. Therefore, the creation of 3D reconstructions is a scientific process and multidisciplinary. 88] The 3D models can be used in a variety of ways. With the Ename Time Line in the connected museum, where scans and reconstructions are superimposed on a large monitor, direct references can be made to the exhibited finds. [89] These superimposed models help to explain and illustrate the function of some of the finds, as can be seen here, for example, on the clasp of a book. 90] A touchscreen in the exhibition invites visitors to explore Ename's history on their own. [91] A timeline on the left of the picture and the info points on the model may help. In this way, they also link to the finds that are exhibited in the museum. The animation also includes the current situation in the form of drone images. [92] In this way, the correspondence between the walls in the archaeological park and the virtual reconstruction of the site takes place directly on site. 93] In appropriate weather conditions, the reconstruction can even be projected directly over the excavation area using a beamer. [94] The implementation of the structural design was followed in Ename by the modelling of the landscape and environment. Since 2018, the visualisation has been extended to include vegetation and other landscape elements. [95] However, this also gives the 3D reconstructions a completely different, softer and more photorealistic expression, which ultimately also has to do with the modelling of light. However, this means that the reconstructions are not static, but always only intermediate stages on the way to a complete documentation of the past. [96] I would like to end the overview with an example where the virtual reconstruction was used for the physical reconstruction of the building remains. In Sagalassos, a relatively well-preserved well house of the Roman Imperial period was excavated. [97] As an augmented reality application, one may superimpose the 3D reconstruction over the ruins to get a good impression of the former appearance of the building. [98] For structural reasons, however, the highly fragmented components of the architraves and cornices could not be placed on top of the original structure. It was therefore decided to recreate the building elements virtually on the basis of 3D scans of the fragments. [99] However, by superimposing the 3D scan and the model, the missing parts were obtained as a negative, which could be printed out with a 3D printer to fill the gaps exactly and stabilise the fragments. 100] so that a gentle reconstruction was possible. Fortunately, not everything was added, because otherwise one would have felt more like being in Disneyland than at an archaeological excavation. 101] In the same way, the frieze with the founding legend of the city in Ephesus, which had been taken to the museum for conservation reasons, was put back into its original context as a 3D print. The original, however, remained in the permanent exhibition as the museum's main piece. 102] 3D reconstruction is also suitable for the museum presentation of sensitive parts, such as the corroded bronze sheets and the wooden remains of an Etruscan tomb. Once the exact position of the finds has been determined in connection with the excavation documentation, a corresponding base can be modelled on the computer using the 3D scans. Again as a 3D print, it forms the support in the exhibition for precisely fitting the sensitive exhibits. [103] Since the early 1980s, archaeologists have been interested in the digital reconstruction of historical buildings with computational methods, which is why this time the focus was once again on archaeological examples. With Heike Messemer's book, however, there is now also a comprehensive overview of the history of 3D models of historical architecture from an art historical perspective. And as really impressive examples of digital implementation, the studies on Baroque ceiling painting and Virtual Reality should also be mentioned. 104] In the field of virtual reality, so much is in flux at the moment that the challenges discussed today will probably soon cease to be challenges. Nevertheless, I would like to address a few central points Like the theory of the digital image, the theory of virtual spaces and their manifestations is dependent on social issues and discipline-specific features. However, it is important not to leave the development of methods and forms of implementation to the gaming industry alone, but to also keep the specific needs of the humanities in mind. Otherwise, every visualisation will continue to look like a computer game and scientific needs such as modelling uncertainty will fall by the wayside. Connected to this is the need to reflect on the historical conditionality and aesthetic demands of the models. After only a few years, the visualisations won't look contemporary any more. But this appearance was also connected with decision-making processes and design specifications that must be critically questioned. Virtual reality can also serve as an experimental field for research theses. Competing hypotheses can be juxtaposed and certain questions about the shape or context of historical buildings and their details can be answered. This field currently lacks methodological stringency and a comprehensive theory that needs to be developed. If one wants to compare and evaluate 3D models and VR applications consistently and according to uniform parameters, the paradata must be standardised in order to be able to evaluate them automatically. This would open up a new starting point for the Digital Humanities for a scientific examination of Virtual Reality. 105] Of the things you should know, some have only been touched upon today and should be explored by you in more depth. These include the history and theory of virtual spaces as well as current positions on the concept of space and its relevance for the 3D modelling of historical spaces. It should be clear to you that the London Charter and the Seville Principles are of central importance for our subject. In order to better understand them, it does not hurt to know the basics and good practice examples of visualising historical information in 3D and 4D. But also the possibilities of textual labelling and visual annotation of simulations and reconstructions are relevant. Without question, however, you should now be aware of the relevance of paradata in (and to) virtual objects and spaces. 106] Create a documentation strategy for the virtual reconstruction or simulation of historical spaces. You will see that there is a lot of work to be done in advance. But at the centre is the creation of a virtual space with the help of a CAD or 3D modelling programme. This is a basic technology that you should learn. But not as an end in itself, but to better understand how elaborate and technically difficult such a visualisation is. Because this always involves reflection on the accuracy, (in)security and aesthetic effect of the implementation of a virtual space. 107] The possible exam questions will now no longer surprise you: "What does the London Charter regulate? Name two principles!" would be one such task. But I could also ask: "What are the characteristics of a convincing VR environment?", "What are paradata? Develop a documentation strategy for the virtual reconstruction of a building!" or "What possibilities does virtual reality offer the humanities? Compare VR with traditional methods of visualisation that we named at the very beginning today." But I could also ask you to give me an example of a good implementation of Virtual Reality in the cultural sector and ask you what distinguishes the project. Or more generally, I would be interested in what you think a good visualisation of a cultural heritage site should contain. 108] I would like to conclude the lecture hour again with a small compilation of literature references. I wish you a good week. The last lesson of our lecture will then be about presenting humanities content to a broader audience, where we can tie in with much of what has been discussed today.