A Late Professor Digitally Scanned Notre Dame. Now His Work May Give the Cathedral New Life 

April 16, 2019, 3:27 PM UTC

On Tuesday morning, after fire ravaged Paris’s Notre Dame cathedral, the EU’s top digital affairs civil servant lamented the loss of one of Europe’s wonders. “Preserving with digitization is important for us and for future generations,” Roberto Viola tweeted. “With Notre Dame we’ve lost a piece of our history.”

Viola’s tweet bore a link to an announcement from a week ago, when 24 European countries including France agreed to cooperate on “advancing digitization of cultural heritage.” This will include a Europe-wide push to create intricate virtual models of key historical artifacts and sites.

But did this initiative come too late for Paris’s 12th century Gothic wonder? Maybe not.

Tallon’s timely scan

Truth is, Notre Dame has already been digitally scanned in great detail by an American art historian named Andrew Tallon. Several years ago, the Vassar College professor used cutting-edge laser scanners to capture over a billion points of data that, when combined in suitable software, can be used to create a 3-D model of the cathedral.

Tallon, who died last year, learned a lot from his scanning exercise—and so did the people running the church. His models revealed that Notre Dame was crumbling to an extent that its administrators had not fully appreciated, and that urgent restoration work was needed to maintain its structural integrity.

A restoration project began last year and, although investigations are still underway, there is reportedly a suspicion that Monday’s fire was accidentally caused in the course of that rehab.

Paris Assesses Damage Following Notre Dame Blaze
Onlookers gaze at the damage caused to Notre-Dame Cathedral following a major fire on April 16, 2019 in Paris, France. (Photo by Dan Kitwood/Getty Images)
Dan Kitwood Getty Images

President Emmanuel Macron has pledged to restore Notre Dame, the main structure of which appears to have survived the blaze. Donations are pouring in from billionaires and others, and French construction groups are also eager to pitch in. But could Tallon’s data help the reconstruction effort?

According to Lindsay Cook, visiting assistant professor at Vassar’s art department, the architects involved in the restoration project that was underway had probably already studied the building carefully. She also noted comments by the chief architect, Benjamin Mouton, that suggested it would be “almost impossible” to create a perfect copy—for one thing, these days there are no oak forests comparable to those that supplied Notre Dame’s beams back in the 12th century.

“That said, Vassar is committed to preserving the late Prof. Tallon’s pathbreaking research, including his laser scans,” said Cook. “If, when the time comes, the [French regional directorate of cultural affairs] or the restoration architect wishes to use Prof. Tallon’s digital record of the edifice to aid their efforts, Vassar will gladly cooperate.”

Digitizing heritage

Assistance might also be available from another source—a project called Inception that receives funding from the European Commission and was highlighted in last week’s announcement about the digitization of European heritage sites.

Inception is run by Roberto Di Giulio of the University of Ferrara in Italy. As Di Giulio explained to Fortune, the project is developing a new way to translate point clouds, such as that compiled by Vassar’s Tallon, into the type of Building Information Modeling (BIM) file that architects can use in their work, or that can be used to present a building in a virtual-reality context. A big part of the Commission’s digitization push is to give citizens new ways to engage with heritage sites.

This technique is rather novel, as BIM models are based on standardized building elements that can be arranged in virtual form by an architect, and the elements of monumental old buildings are anything but standardized. Di Giulio said artificial intelligence will ultimately be required to learn about and virtually recreate all the types of objects that went into a gothic building, for example. But Inception’s system could still prove useful in the case of Notre Dame, he said.

“If we have Notre Dame on our platform, you could go there and get everything you need for reconstruction,” said Di Giulio, who said this might be possible if Tallon’s data included enough points. “Of course we would be honored to give help.”