The Digital Twin that will restore Notre Dame de ParisTue Apr 16, 2019
The world mourns as the smouldering remains of the Cathedral of Notre Dame lays still on the banks of the Seine. Following a massive fire that engulfed the 850 year old French gothic architecture on Monday evening.
The wailing of a nation filled the air as onlookers paid tribute to the iconic Parisian landmark by singing hymns like “Ave Maria”, while the iconic spire restored by renowned French architect Eugène Emmanuel Viollet-le-Duc in 1844, imploded into the main hall of the cathedral.
“Spira, spera. (breathe, hope)” ― Victor Hugo, The Hunchback of Notre-Dame
Perhaps in the most poignant of ironies, Victor Hugo said it best. Spira, spera; for there is hope.
In 2015, National Geographic published an entry detailing how art historian Andrew Tallon painstakingly used precision laser scans created for the construction industry to map out in great detail the Notre Dame Cathedral.
Laser scans, with their exquisite precision, don’t miss a thing. Mounted on a tripod, the laser beam sweeps around the choir of a cathedral, for example, and measures the distance between the scanner and every point it hits. Each measurement is represented by a colored dot, which cumulatively create a three-dimensional image of the cathedral. “If you’ve done your job properly,” says Tallon, the scan is “accurate to within five millimeters [.5 centimeter].”
Let us hope Andrew Tallon’s deconstruction of the cathedral in 2015 will now help with its reconstruction.
Fortunately, the Architecture, Engineering, Construction industry has pushed forward in the development and visualisation of such point clouds since, compared to a few years ago, where it was highly impossible for such detailed data sets to be rendered into a three dimensional model that was manageable for actual work to be carried out.
Another source of hope comes from the video game industry which frequently utilises highly detailed virtual assets of buildings and structures in game.
While creating the best selling game ‘Assassin’s Creed Unity’ , its creators Ubisoft poured over photos of the cathedral to get its recreation just right, and worked with texture artist to make sure that each brick is as it should be. It even went a step further to have historians help decipher the most minute of architectural embellishment on the buildings facade.
The rebuilding processes would also benefit from the use of Building Information Modelling (BIM), which will further add constructional depth to both Tallon’s and Ubisoft’s efforts.
Architecture as fragile and meticulous as Notre Dame will require more then just a 3D replica but also intricate planning of the construction sequences involved for successful restoration. Enhancement tools that allow for the Virtual Coordination of building models, will enable both designers and builders alike to make for more effective and procedural restoration.
The usage of BIM to preserve historic monuments have been done before; like that of Mount Vernon, George Washington’s iconic mansion, when it partnered with Quinn Evans Architects and ESRI (Environmental Systems Research Institute).
Hopefully the technological giants of the Construction software industry, Autodesk and Archicad will lend its expertise and technology to such a project.
With the world watching and the announcement of French President Emmanuel Macron’s declaration, the Cathedral of Notre Dame will be rebuilt. And perhaps with far more accuracy as compared to its previous restorations. With the help of technology and the human endeavour, from which such beauty was created in the first place.