Strolling through the streets of Burgos in 1921, accessing the entrance to a mine in León that disappeared in the sixties, identifying every detail of a 13th-century pilgrim hospital in La Rioja, of which only a few ruins survive today, or sneaking into the construction of the cathedral of Santa María de Vitoria and observe, in the first row, how the workers raise its walls from primitive scaffolding. All these examples are wishes come true… Virtual reality, of course. Because neither the center of the city of Burgos is today as it was a century ago, nor have the workers of the Gothic cathedral in Vitoria prolonged their hard working hours to the present day. But can heritage that no longer exists really be recovered? The answer is yes, and you have to look for it in the virtual reconstruction.
A challenge that the 3DUBU working group of the University of Burgos has been posing every day for more than a decade, a period in which they have developed dozens of projects such as those mentioned. History has placed in the foreground the heritage that has survived, the one that is still standing. But what about, for example, the wooden cabins of the medieval city of Portilla (Álava), swallowed up by time due to their ephemeral architecture? "What exists is protected by a lot of laws since the Napoleonic wars; however, there is no law, neither Spanish nor international, that protects what has already disappeared", questions Mario Alaguero, professor at the University of Burgos , who goes a step further in this idea. "In the first case, there is financing to conserve it; for what does not exist, there is no money."
This is how designers, computer programmers, communicators, historians and archaeologists become guardians of heritage that has vanished. Together, in a transversal task, they have proposed to "revive" periods of our era that have already been overcome, buildings mistreated by the passage of time or sites on the brink of their last breath. The objective? Gather that knowledge in the so-called "virtual reconstruction", a term that "is beginning to be standardized —says Mario Alaguero—, but there are those who criticize us for rebuilding something that is not very well known what it was like". Precisely, that is the crossroads: can a reality be brought to life when key data is missing? The solution lies in the so-called "levels of detail" of the reconstruction, a complex aspect to which Alaguero, professor in the area of Audiovisual Communication and Advertising at the University of Burgos, dedicates his doctoral thesis.
When there is reliable information, when archeology or historical sources have something to hold on to, the team "feels safe", stands on firm ground and brings to life hyper-realistic reproductions, with an impressive level of detail. This is well known to the residents of Burgos who have walked its streets as they were in 1921. "We have used a map made by the French in a battle that took place here in Burgos and the scanner work of the LIDAR program (which takes reliable measurements of the terrain in 3D)," explains Alaguero. So the result, which is accessed through 360-degree videos from the mobile phone, is "quite faithful".
Precisely, "Burgos 1921" is the work highlighted by Bruno Rodríguez, audiovisual communicator, also a member of the 3DUBU team. "Being able to reconstruct what the city was like a hundred years ago has allowed me to see details that I didn't know and, moreover, in a very different way, almost as if I were in the Matrix." And not only that. The experience has been transferred to the streets, where the people of Burgos have only had to scan a QR code with their mobile phone to open a video on YouTube. "It is work that has made an impression on people, I have seen its impact on the residents of Burgos, who have been able to appreciate the evolution of their city," admits Rodríguez, who dedicates his doctoral thesis precisely to the reconstruction of heritage through of virtual reality.
Although the work team of the University of Burgos does not always have such reliable data. When archeology and documentary sources are scarce, it is necessary to go down a step in the level of detail of the reconstruction and, perhaps, imagine what a building that is no longer was like. Make guesses. Then comes the quicksand. This is how, for example, they faced the reconstruction of the pilgrim hospital of San Juan de Acre, a 13th-century building in the town of Navarrete (La Rioja), currently in ruins. They drew a first drawing on paper, converted it into a three-dimensional model and submitted it to the analysis of a historian and an archaeologist. "Each time there was a documentary gap, we proposed various hypotheses and chose the most appropriate," says Mario Alaguero. Finally, an anecdote —an old document referring to how children threw stones at the hospital bell tower from a spindle— made it possible to locate the tower correctly on the plan.
However, this is not about inventions, nor about making society believe what it is not. "This discipline requires us to be transparent," Alaguero clarifies. Hence, together with the hyper-realistic virtual reconstruction of the Rioja hospital, they created an identical model in which each part wore a color, like a kind of traffic light of historical reliability. Thus, the part that was based on archaeological evidence, the safest, was painted green; the level of fidelity in the proposal was descending through yellow and orange to red, "pure conjecture" and blue, "what we think should have been there", explains the professor from the University of Burgos.
But the work does not end with the digital model. Alaguero reveals how they get the final design to give off such a realistic feeling. Starting from the volumetry, they work on how to dress the walls and roofs of the building. The problem is that those colors, those shades, are not found in the cities of the 21st century, but rather in empty Spain, which lately is a resource for everything. "We look for the textures of the time, the appearance that the constructions could have had in the past. We visit many towns, especially those that are abandoned, that preserve the most original materials, the oldest, to take samples", explains the specialist. Finally, they "paint" walls and roofs with these textures. The result is as if that disappeared and forgotten heritage, which already seemed relegated to absolute oblivion, was reborn.
Now it remains to be seen what one of the most severe disciplines says about all these advances with anything that goes beyond scientific evidence. "Virtual reconstruction is one of the great advances of our time, a tool to disseminate and socialize history, which otherwise would not be understood," says José Luis Solaun, researcher and member of the UNESCO Chair in Cultural Landscapes and World Heritage. the University of the Basque Country. But perhaps one of the most positive aspects of the collaboration between archeology and virtual reconstruction is in the nuances it brings to the final project. "Many times, archaeologists have a mental image that is not captured on paper; when a programmer recreates the volumetry of a building, of a house, in 3D, that helps us ask ourselves questions, because we did not imagine it that way", Solaun acknowledges.
A benefit that Bruno Rodríguez clearly defines, and that goes beyond the ease of the public to understand heritage through digital technology. "It is also useful for historians and archaeologists: when they have a reconstruction in their head it is difficult to know what they have failed at; when they see it, they realize that what they had imagined might not be the case in reality and it helps them to make self-criticism" explains the communicator.
Both advantages - the understanding of the disappeared heritage by a public not initiated in history and the 3D visualization of archaeological evidence - come together in one of the most celebrated proposals of the 3DUBU group. Those who access the bowels of the Vitoria Cathedral —a "giant" project— can enjoy the experience of virtual reality, with which "the sensation of immersion is very powerful", describes Mario Alaguero. "Visitors put on their glasses and can travel to the past; see how they worked with scaffolding and cranes in the Middle Ages, how they made the falsework or the stonework process and, at a certain moment, they can rise up to twenty meters in height and have an impressive vision of the construction process", he details.
The result is in the figures: an experience planned for one year has been extended for two more seasons. "Virtual reconstruction is a full-fledged pull, but not only at the heritage level, but also economic and tourist." Bruno Rodríguez underlines a not insignificant added value. "In Vitoria, visits grow and more money is generated, thus demonstrating that heritage, in addition to its historical value, is a good investment that can help make a place economically dynamic," he says.
Similar is the work carried out in the ruins of Portilla, an ancient city founded by Sancho III of Pamplona in the 11th century. "People recognized the castle or the church, but they had difficulty imagining what the houses and streets were like, of which remains are barely a meter high", describes José Luis Solaun. "Looking at the ruins, the public doesn't understand what these houses were like, if they were one or two stories high or what they looked like inside," he adds. The archaeologist affirms that this "deficit" of understanding "we have tried to alleviate through 3D recreations". The conclusion is that today it is easier to imagine how the ancestors of the Alava city lived.
From this it follows that virtual reconstruction can be a key tool in the preservation of heritage that no longer exists. "The remains of castles and churches are already protected, but the misnamed minor architecture is also heritage and is not cataloged," warns Solaun. The researcher cites interesting examples of a relatively recent heritage —from the 18th to the 20th century— that has not survived, such as "farmhouses, huts or shearing areas" and that runs the risk of being forgotten forever.
Archaeologists only put one condition. "I am not in favor of virtual recreations without the scientific support of archaeology," says Solaun, a professor at the University of the Basque Country. It is not an attack of corporatism, only the fruit of reflection. "When you use resources for reconstruction, you're taking them away from site research," he explains. "When you create an image of a place without scientific evidence, in the future it will be very difficult to erase that idea from society if it turns out that it was not correct," he reasons. Examples are not lacking, nor paradoxes either. And there are not a few examples in which the false image has more credibility than the one that is more in line with historical reality, such as Romanesque paintings in the churches of the Bohí valley in Lleida, a modern replica that, however, the visitor believes to be witnessing those of centuries ago..