Rock-Hewn Churches of Ivanovo - 3D Reconstruction

Rock-Hewn Churches of Ivanovo3D Reconstruction

The project description

DATE

June 2021

SERVICES

3D Reconstruction

INDUSTRY

Cultural Heritage

Introduction

Our passion for the cultural heritage of Bulgaria is the spark that drove us to use our 3D skills to preserve it and showcase it to the world. To breathe life into it in an innovative way. And once again, the flame leading to the past was ignited with an invitation from the esteemed Regional Historical Museum in Ruse. This was the beginning of an exciting digital expedition.

Faced with the challenge of resurrecting the medieval Bulgarian spiritual center near the village of Ivanovo – the ”Holy Virgin” medieval church – we undertook the exciting task of combining art with the capabilities of 3D technologies. A process in which, step by step, an impressive 3D reconstruction of an object that had been destroyed over time would be born.

Our mission was not only to depict the monastery as it was in the 14th century but also to create a virtual reality experience that offers each visitor a journey beyond time.

Driven by authenticity and guided by our passion for history and innovation, we dedicated our efforts to bringing the remnants of this spiritual center to life. Оur team of 3D artists, historians, and VR experts began the process with meticulous data collection and research. It was of the utmost importance to reconstruct every fine detail of the architecture of the ecclesiastical center.

Delving ever deeper into historical accuracy, our interest in this extraordinary project became a driving force. Thanks to the availability of various photogrammetric techniques, high-quality texturing, and dynamic lighting, we made tremendous efforts to bring a bygone era into the present as accurately as possible.

In direct collaboration with the Regional Historical Museum in Ruse, our digital journey concluded with the opportunity for every visitor to make their own virtual leap through time. A leap that allows them to immerse themselves in history. This endeavor was not only a testament to the value of the heritage left to us in the village of Ivanovo but also another chance to preserve and sustain its spirit.

Join us on a journey where technology meets medieval art. This is a journey that strives for excellence in 3D architectural visualization and digital archaeology.

BACKGROUND

Background

The experts from the Regional History Museum in Ruse have worked hard for decades to document and preserve every detail of the Rock-Hewn Churches of Ivanovo. With help from many partners and supporters, the museum aims to show the lasting beauty of this special place and promote Bulgaria’s rich cultural heritage. And so, our journey back in time began with a careful study of the remains of the ‘Holy Virgin” monastery. Thanks to the valuable support of historians and archaeologists, we took slow but confident steps toward exploring every detail of the church.

Unlike traditional monasteries, which consist of 1-2 churches, monasteries, and farm parts, Ivanovo features a variety of small rock churches, chapels, and cells. All of these are carved at different heights into the rocks of the picturesque canyon of the Rusenski Lom River. The monastery has a complex structure, integrating the complexes of rock chambers around the so-called ‘Buried’ Church of ‘St. Archangel Michael’. The two churches most richly decorated with frescoes are the ‘Collapsed’ Church and the Church of the ”Holy Virgin”.

The monastery was abandoned for hundreds of years and then rediscovered in the early 20th century (1914). Karel Skorpil mentioned it in his work, ”Inventory of Antiquities along the Rusenski Lom River”. Later, the complex was included in the UNESCO World Cultural and Natural Heritage List.

The problems regarding the preservation of the rock churches are significant. The primary concern is related to the instability of the rock massif. Air pollution and rainwater infiltration into some of the chambers also have a substantial impact. Unfortunately, these are not the only causes of their deterioration.

To enter the church in the past, there used to be an entrance passing through a wooden external platform, which no longer exists today. Additionally, there was a rock collapse caused by human interference in 1976. As a result, this part of the church was lost forever. That’s why we relied heavily on the expertise of archaeologists. Our goal was clear: to gather as much detailed information as possible about the original appearance and layout of the church complex.

Relying on the capabilities of modern 3D scanning technology and with the assistance of experts, we meticulously reconstructed the church of the ”Holy Virgin”. Our aim was entirely focused on presenting the details with maximum accuracy and precision, ensuring that the digital model would recreate them exactly as they were in the 14th century.

It was crucial for both us and the 3D project to remain flexible when encountering new discoveries. As archaeological excavations continue to uncover deeply hidden secrets from the past, we have had to incorporate them into our reconstruction work.

Photogrammetry & Scanning

After we set our goal and started our work, it was time to capture the details of the “Holy Virgin“ church. We used laser and structured light scanning to gather data, along with aerial and ground photogrammetry.

Our expedition was accompanied by the most advanced technologies, allowing us to digitize the rock monastery. For the photogrammetric process, we utilized two different drones: the DJI Matrice 210 RTK and the DJI MAVIC 3 PRO. Through them, we managed to resurrect the richness of the landscape from its ruins. Despite the difficulties posed by the terrain and meteorological conditions, our team was fully absorbed in the pursuit of complete authenticity.

Scanning complex details

In addition to our efforts directed towards reconstructing the church, we also had to consider the intricately painted interior of the former monastery. For this purpose, we used Artec Leo and Artec Ray to scan its complex details, transporting them from a long-forgotten time into a new digital world.

Creating a detailed 3D architectural model

With the available data in our hands, it was time to begin the actual work: creating a detailed 3D architectural model of each of the rooms. It was time to process and refine the raw scan data into a highly detailed digital 3D model. All of this was possible thanks to sophisticated software tools like Artec Studio and Reality Capture.

Given that we already had a large number of images and scans at our disposal, we needed to dedicate sufficient time to sift through and process them. Carefully, we had to merge data fragments in such a way that they accurately reflected the appearance of the ”Holy Virgin” Church.

Every small detail in the interior served as a priceless addition to the overall virtual 3D reconstruction. The variety of the remains of the frescoes recreated a completely different sense of history. Something that you can experience, not just see.

Approach & Methodology

To gain an even greater understanding of the nature of such a site, our friends from the Regional Historical Museum provided us with a large amount of diverse imagery, including various additional information. We discussed how the monastery functioned in the past, what each room was used for, and so on.

Post-processing of the exterior

In the meantime, we finalized the computation and post-processing of the raw scan data of the exterior.

You can see the results in these images.

Detailed geometry of the interior

Additionally, we composed the gathered data from the Artec Ray scanner to end up with an extremely highly detailed 3D scan geometry of the interior.

Comprehensive texture information

We also needed highly detailed texture information. This is where the Artec Leo raw scan data came into play.

Since the overall internal area was scanned in pieces, our first goal was to combine all of the individual scans into a single scene that you can see below.

Real-time geometry creation

The challenge came when it was time to align the two types of scans, extracting the information provided by both. Here, the ultimate goal was to combine them into a real-time geometry that had all of the diffuse texture information from the Leo scan and all the topology information of the Ray scan.

It was time to make a low polygon version of the 3D interior of the monastery. The raw scan had 35 million polygons, but the simplified version only had 20-30 thousand.

An essential part of this step is correcting various “flaws”. This means that necessary adjustments needed to be made where the scan did not turn out well or where there were holes and missing parts. Typically, these are modeled manually.

This was precisely the case with the small terrace of the church, which needed to be reconstructed.

Once we had the new simple model, we baked all of the diffuse texture information from the scan onto the low poly mesh.

This was the starting point for our digital 3D twin of the ”Holy Virgin” church.

Unreal Engine Digital Double

We then refined the textures in Substance Painter and fixed any missing areas. We also built all of the rest of the PBR textures needed for a photorealistic result. And of course, we textured the main parts of the church complex, like stairs, terraces, and wooden wall.

This stage required creating a scene in Unreal Engine, where we had to transfer the model and carefully prepare it for a VR experience. In the preparation process, attention to detail was crucial, ensuring that everything was finely tuned to offer a realistic experience. While completing this part, it was really satisfying to see the scene come to life.

Equally important was to illustrate the surrounding environment as seen from inside the monastery’s windows. For this part, we used a 360-degree panorama captured with the DJI MAVIC 3 PRO drone. Finally, it was time to create suitable lighting and atmosphere.

Restoration of the interior

The next phase presented us with yet another exciting challenge: the moment to recreate the appearance of the church as it was in the 14th century. This involved some significant changes to the structure of the space.

The current entrance is a hole made in the early 20th century when the monastery was rediscovered. The place where the hole was created was the location where the iconostasis of the church was back in the 14th century.

Back then there was an external entrance, where the small terrace is now located. It was reached via a wooden platform (which no longer exists), evidence of which experts discovered in the rock itself.

Additionally, we had to completely revive from the ruins the destroyed part of the church, where there is currently a wooden wall.

It was also crucial to meticulously clear all the holes and cracks in the rock with a high degree of precision. When the church was in use, it was carefully plastered from the inside.

However, at a later stage, vandals broke the plaster, searching for valuables hidden beneath it. In the images below, you can see where and how we made these changes.

Template of the frescoes

Only after restoring the interior’s appearance could we officially proceed with the restoration of the frescoes. A crucial step here was visually representing the divisions between the individual frescoes (zones) and presenting them to experts for confirmation.

Historians from the Regional Historical Museum in Ruse, particularly the late Mr. Stoyan Yordanov, have spent decades researching them. We relied on their work to restore them down to the smallest detail.

At this stage, we began the slow and careful work of painting the frescoes, which took six months to complete. We followed all the canonical rules.

Restoring the exterior

At the same time, we reconstructed the lost exterior, including a wooden platform used by the monks. Again, we followed a concept developed by Stoyan Yordanov based on his findings.

The final step involved assembling the interior and exterior into one unified scene. We had to complete all frescoes, murals, and details necessary to achieve the sought-after authenticity and precision. This included creating the iconostasis and candleholders.

Collaboration with historians and experts was also crucial during this process to ensure historical accuracy. That’s why, in the end, we reviewed each fragment together to assess how accurately they reflected the 14th-century reality within the church.

After long and hard work, the final product was ready: a VR scene that lets visitors of the Regional History Museum in Ruse experience the church ‘’Holy Virgin’’ as it is now and as it was in the 14th century.

In Conclusion

Bringing the spiritual monastery in Ivanovo back to its 14th-century glory was not easy. But with the right preparation, 3D visualization technologies, and help from historians, experts, and artists, we did it. We faced many challenges, but knowing the true value of this place kept us motivated.

Achieving historical accuracy was crucial for the 3D reconstruction. We wanted to show the project in its authentic form to the Regional History Museum in Ruse and future visitors. We followed all the available information and even the details hidden under the church ruins.

The process was tough, but by staying flexible and aiming for perfection, our hard work paid off.

Scanning such a unique object in the rock required careful study and precise calculations. This helped us restore the beauty of the church’s Holy Virgin.

The final result was very satisfying. Today, the Regional History Museum in Ruse has an interactive VR product that captivates visitors, especially the young generation. This 3D reconstruction helps them imagine what the churches looked like and what each cell’s purpose was in the 14th century. The church of the ‘’Holy Virgin’’ in Ivanovo has been preserved in the digital world forever. Now, anyone can take an exciting journey back to the 14th century and immerse themselves in its spirit and atmosphere.

With 3D visualization technologies, modern solutions, and a passion for cultural heritage, we restored the splendor of this spiritual center. We brought it back to life and took the first step toward promoting it globally.