SumDU scientists, in collaboration with the O. M. Beketov National University of Urban Economy in Kharkiv, are implementing an interdisciplinary project on virtual reconstruction of lost cultural heritage sites in Sumy Oblast.

Under the guidance of Ivan PAVLENKO (DSc in Technical Sciences, professor), a team of researchers creates 3D models of historical monuments, including the early 20th-century architecture and the Zelenohaiskyi archaeological complex. The main contractor is architect Ihor TYTARENKO (a junior researcher at the SumDU Research Department and co-founder of the Future Sumy community. In this interview, he talks about a new stage of work – photogrammetry, its possibilities, challenges, and the role of digital reconstruction in preserving cultural identity of the region.

How extensive are the losses of cultural heritage in Sumy Oblast?

– The losses are extensive, especially in the border areas. We have confirmed cases of destruction of architectural monuments in Myropillia, Krasnopillia, and Yunakivka. First and foremost, these are monasteries and churches. But that is not all: we are also talking about historical architecture in cities and villages in general. The destruction is not only the result of air strikes – often the cause is combat operations in populated areas. This is a very topical issue. Sumy itself is also under threat, in particular the historical area we are currently working on. Awareness of this danger motivates me to actively study and research. We are working to record the condition of cultural heritage sites by scanning them and creating digital copies.

How did you choose the monuments for reconstruction? Why the historic center of Sumy and the Zelenohaiskyi archaeological complex?

– We focused on the historical area of Sumy, where the largest amount of architectural heritage is concentrated. First of all, these are Soborna and Voskresenska Streets as well as Pokrovska Square. This has been the city heart since days of the Cossack fortress. It was here that authentic Sumy architecture was formed, and it is here that the most interesting examples of buildings have been preserved. The historical area of Sumy is much larger, but these locations became the focus of our attention in the first stage. We are researching buildings of historical and architectural value. This is important because many of them are in danger of destruction. A separate, but no less interesting part of the project, is the Zelenohaiske settlement, which belongs to the archaeological heritage. It was here, even before the arrival of the Cossacks, that a developed settlement already existed. Zelenohaiske is one of the largest settlements in the area, but unfortunately, it has been little studied. The available information is insufficient, especially regarding its structure as an urban formation. The mounds around it have been better researched, but the urban planning aspect of the settlement remains a “blank spot.” Therefore, we set ourselves the goal of collecting as much information as possible and recreating the Zelenohaiske settlement in 3D. This will be an attempt at digital reconstruction of the space from which, in fact, the history of our region began.

Is virtual reconstruction mainly a research activity or a way to bring historical objects back into people’s consciousness?

– One hundred percent, it’s about bringing them back into consciousness. It is very important for people to know their history, to understand what exactly was lost and whose fault it was. Without this, it is impossible to realize the value of what we have today. The historical center of Sumy was largely destroyed, primarily due to the actions of the Soviet authorities. At that time, there were different approaches and priorities, which led to the loss of valuable architectural and urban heritage. A striking example is Mykolaivska Street. Today, in its place stands the completely reinforced concrete Independence Square. But before, it was one of the most beautiful streets in the city. The Mykolaivska Church stood here, and the street connected Troitska and Soborna Streets. The architecture in that area was incredible. Unfortunately, it is now completely lost. Mykolaivska Street is also included in the list of objects for research. We would also like to recreate it, although it will be difficult because we only have a few photographs from different angles. So, we will have to piece together the puzzle.

The project is now entering the photogrammetry stage. What does the process of creating a 3D model look like?

– Photogrammetry is an interesting and rather lengthy process. It starts with collecting sources: we are interested in literature, archives, old plans, and photographs. Because if an object is completely lost, it can only be recreated based on the information that has survived to our time. Another thing is monuments that have survived to this day. Here, the object is photographed from many angles. It is very important to record it via a drone, to cover as many angles as possible. Because if some part is not captured in the frame, it simply will not be on the model, and there will be gaps. Next, all photos are processed via special software. First, a point cloud is generated, which is converted into a geometric model and covered with texture. The photo quality determines how accurately the object geometry can be reproduced.

What technical limitations or challenges arise when creating 3D models via photogrammetry?

– Sumy is located close to the border, which greatly limits the use of drones for photo documentation. It is quite difficult to obtain permission, so we are currently looking into this issue. But where it is possible to do without a drone – simply taking pictures with a camera or phone – we work within the limits of what is permitted, without violating any rules or safety requirements. In the Zelenohaiskyi case, the goal is to scan the relief of the small settlement where the fortress was located. But the trees are a major obstacle, and even using a drone would be quite problematic there. Besides, there are weather considerations. For high-quality scanning, it is important to avoid bright sunlight, as glare and sharp shadows affect the texture quality. At the same time, this does not affect the model geometry itself, but for optimal results, a soft, diffused light scene is required. The ideal weather for shooting is a cloudy but dry day.

Is photogrammetry sufficient for a complete reconstruction, or does it need to be combined with other methods?

– Photogrammetry is a way to capture an object as it exists today. It is often used by architects and engineers to create accurate models that they then work with. In our case, the goal is slightly different: we capture objects to preserve them in digital form, as many of them are at risk of destruction. Photogrammetry can also be used in design. Such a scan of the facade allows you to take almost accurate measurements, with an error of 2-3 centimeters. Therefore, laser scanning is usually applied for accurate purposes, where the error is reduced to a few millimeters. But it is much more expensive and requires special expensive equipment. In general, photogrammetry is an effective and affordable tool that allows you to accurately capture objects and then work with them in 3D models.

Is it possible that in future, real lost monuments will be restored via these 3D models?

– We capture facades, namely exterior of buildings. We are not currently working on the interior layout. In addition, not all interiors are accessible, as they may be private or communal property. But when it comes to recreating the exterior, it is entirely possible. Although, in general, the photogrammetry technology allows a monument to be completely rebuilt if it is lost.

How can reproduction of monuments in digital space impact on public memory and self-identification?

– First of all, digital models can be used to create virtual tours, 3D printing, and models of lost monuments or entire streets. This helps not only to preserve history, but also to make it closer and more accessible to people. Such tools are also important for promoting the city. We have to show that Sumy is not only a border town, but also a space that is moving forward and using new technologies. To be modern, you have to explore, invent, and implement new things. And digitization of cultural heritage is one of the steps towards this.

For you personally, what does participation in this project mean as an architect and scientist?

– For me as an architect, it is a great opportunity to explore architectural monuments and work on their preservation. I am inspired by the aesthetics of our city: the architecture here is very diverse, and I want it to be preserved and, if possible, even revived. As for Zelenyi Hai, I am interested in the history of our region. This heritage from the Middle Ages and Kyiv Rus is an important stage in the history of Sumy. And this cultural site should definitely be known to people so that they can appreciate and preserve it. As a scientist, it is important for me to contribute to development of our city. I strive to conduct my research in the context of Sumy because I love this city and want the scientific community to actively develop here.

Iryna TRACHUK (ZHT-31 student)

Photo – from the archive of Ihor TYTARENKO