The ashes and aftermath of Notre Dame
Can 3D models save the day?
contributors: Jessica Morris, Kelsey L Unger, Melissa LaFortune, Michela Kuykendall
At the time of writing, Notre Dame has been reduced to a framework and rubble from a massive fire that ravaged the building, and the treasures held inside. While most of those treasures were saved due to renovations or people running into the fire to rescue relics, the building itself could not be rescued from danger so easily. With tens of millions donated to rebuild the cathedral, the question turns to how it will be rebuilt, and based on what resources? In this blog, we will explore Notre Dame’s history, its status as a World Heritage site, and possible sources for models and designs of the building, to be used in restoring the building.
Notre Dame is more than an old and beautiful building; it captures the styles and changes in the city through additions to the structure atop its original form, adding elements like the spire well after the building was first completed. However, that age and original design created severe weaknesses in the structure when the fire started, as their fire safety system “…was based on the assumption that if the cathedral ever caught fire, the ancient oak timbers in the attic would burn slowly, leaving ample time to fight the flames…,” and to notify the authorities “…a guard at the cathedral first had to climb a steep set of stairs to the attic…” (Bennhold). In that delay, the fire grew out of control and devastated the building, leaving a hollow shell of what had been recognized as having Outstanding Universal Value by UNESCO.
Notre Dame is a World Heritage Site recognized by UNESCO, but why did it achieve such a status? Its 1991 inscription is part of the Paris, Banks of the Seine World Heritage site in France that captures not only the cathedral, but a wide range of French landmarks and structures like the Eiffel Tower, the Louvre, and wide boulevard that influenced town planning and development of the city in the late 19th and early 20th centuries. Within UNESCO it falls under three of its criteria for a World Heritage site, with criteria four most significant to Paris and the Notre Dame fire: “United by a grandiose river landscape, the monuments, the architecture and the representative buildings along the banks of the Seine in Paris each illustrate with perfection, most of the styles, decorative arts and building methods employed over nearly eight centuries” (UNESCO).
Once the embers were put out, Notre Dame and the city of Paris were left with the question of how to rebuild the structure. Private donors and companies have donated more than 700 million dollars to restore the cathedral alongside the support of France’s President Macron, leaving the question of what the restored building is going to look like. As it turns out, the cathedral has its own savior in Andrew Tallon, an art professor who, by using special lasers and 3D modeling software, had modeled the church long before the fire. Through this long, meticulous process, Tallon created a model that is “…now the only modern record of the cathedral just as it was on the day it was partially destroyed, which will prove invaluable to those who hope to rebuild it…”. Although he died six months ago from cancer, Andrew Tallon’s work and model can serve as a strong guide to the rebuilding process, and the necessity of preserving World Heritage sites.
Notre Dame presents us with numerous examples of digitally capturing a World Heritage site for future generations, preserving them in the case of natural disaster, deliberate assault, or a careless action that results in destruction. Andrew Tallon’s model above presents us with an obvious example but creating a digital model of a site does not need to be so time-consuming. With a phone camera and software like Agisoft Photoscan, similar individuals can set out to 3D model locations in a manner limited primarily by the cost to go there, and the computer hardware available. An unlikely example has come from the video game world, where Ubisoft’s Assassins’ Creed Unity has attracted significant attention to its virtual recreation of Paris and Notre Dame, presenting an unlikely candidate for a resource to explore the cathedral. Examining the cathedral and other World Heritage sites can provide very useful sources for the appearance and design of the site to rebuild it as it existed instead of just through images, restoring the site to its previous state.
But when Notre Dame is restored and rebuilt, will it be authentic?
Notre Dame is iconic and highly recognizable in the French skyline, but it has changed in structure and for the people of France in the centuries since its completion in 1345. Individual elements like the stained glass had been replaced periodically, but the chaos and uprisings in the French Revolution period inflicted serious damage to Notre Dame as different groups like the Cult of Reason took it over. This damage resulted in a full restoration campaign in 1844 to the church, which included
“…the reconstruction of the arrow…the restitution of the sculptures…murals in the side chapels…,” and a “…complete overhaul of the great organ,”
showing a mix of restoring damaged elements and introducing new ones a century and a half before the fire (Historique de la construction, 2019). Thus, under strict definitions Notre Dame itself might not have been authentic before the fire despite its status as a World Heritage site, altered and improved by new elements since the initial construction was finished.
New conventions within UNESCO have also resulted in the difficulty of providing a concrete answer about whether a World Heritage site is authentic, whether through changes to its buildings or shape. Where the Venice Convention stressed complete authenticity in the original building and materials, the 1994 Nara Convention states that
“…authenticity judgements may be linked to the worth of a great variety of sources of information. Aspects of the sources may include form and design, materials and substance, use and function, traditions and techniques, location and setting, and spirit and feeling…” (UNESCO, 1991).
Under that judgement a restored Notre Dame could be authentic if the building maintains the old cathedral’s style, use, and importance to religion and France as a whole, even if the building has been altered or built with new materials or features like the spire. However, the question of authenticity will still be difficult to answer with a consensus as the objects lost in the fire cannot come back, those that survived may not be the same again, and it may take a very long time to re-create materials similar to those used to build the original cathedral.
Questions about authenticity may be rendered further moot by the fire and its damages, as they may make it impossible to completely restore the building. In one example, the cathedral’s famous pipe organ was spared in the inferno, but may have been damaged by efforts to put out the fire and the fire itself, and that it may be very difficult to restore the organ, as “…that’s normally done by hoisting it up on a pulley attached to the roof, which is now gone” (Garcia-Navarro, 2019). In addition, accurate reconstruction may be completely impossible as
“The trees that made up the roof’s wooden structure were cut down around 1160, and some sources estimate that the beams accounted for 13,000 trees, or about 21 hectares of Medieval forest, many of which had been growing since the 800s or 900s” (Smith, 2019).
The techniques will similarly lack complete accuracy, since “…the stone that makes up the cathedral would be cut using machinery, not by hand by small armies of stonemasons as in the 12th century…” and “While architects have enough detailed information about the cathedral to pull off a technically very precise reconstruction, the craftsmanship is unlikely to be the same” (Smith, 2019).
Notre Dame can and will be rebuilt, through the donation of millions from around the world and a vast sea of materials to restore the cathedral. That sea of materials and 3D models like Tallon’s may not be enough though, as the differences in resources available and techniques used may result in a compromise that renders the building un-authentic. But that doesn’t have to be the case; Dresden in Germany was almost completely wiped out in World War II but was restored over decades to become a new city, one that reflected the past while incorporating new lessons and computer technology to improve the city. Notre Dame can similarly improve itself through modern techniques and 3D models to create a stronger building, one that captures the essence of the original in its style while small changes are made to better protect the building from accidents or other fires. Through digital technology like 3D modelling both versions of the building can exist, allowing visitors to explore the old building and new to see how they are different, and by digitally stepping into the cathedral, experience the building in a new form.
