The heart-breaking fire at Notre Dame Cathedral has caused devastating damage. French President Emmanuel Macron’s has vowed to “rebuild Notre-Dame together”. And out of the tragedy comes a tiny piece of good news to help…

Notre Dame took two centuries to build, and less than an hour for its roof, spire and interior to be destroyed in flames. But thanks to Art Historian Dr. Andrew Tallon and some divine timing, Notre Dame still lives on as over a billion points of data in Virtual Reality, accurate down to the millimetre. This virtual building can now be used for the reconstruction.

It was just five years ago that Andrew worked out how to use the latest VR technology to capture Notre Dame with laser scanners and spherical panoramic cameras. Setting up 3D cameras in more than 50 locations inside and around the cathedral he made a virtual replica of it as a super-accurate 3D ‘point cloud’.

Why Notre Dame? Andrew said he had been obsessed with the cathedral since he was a 4th grade student visiting it for the first time: “I had this little guidebook and I annotated it like a nutcase.”

“I longed to know the usual questions. Who made that thing? How did they make it? Could I ever go up in one of those passages?”

He returned, over 30 years later, after a life majoring in music, studying gothic architecture, and becoming an Art Professor - with the goal of capture the cathedral in Virtual Reality. He says of his return: “That very same thrill that I longed for as a kid looking up at those passageways in Notre Dame -‘I want to go up there'—well, here I am up there, and it's thrilling.”

Soon after his work was finished, Andrew died at the end of last year. His mentor who inspired him to pursue his Notre Dame project, Robert Mark, died just months ago. Fellow historian Robert Bork said “Both of them loved this building. I’m just glad they didn’t have to see this.”

The wood forming the roof of the cathedral dates back to 1160 - one of the oldest surviving roofs of its kind. Even if it is rebuilt to exactly the same spec, it will not be the same as the original. But through a fortunate collision of new technology and one man’s passion, we are at least able to accurately rebuild this historic treasure.

And it can now be done more accurately than at any other time in Notre Dame’s 700 year history.

Little would Andrew have thought that within half a year of his death his work would now be used for such an important task. Combined with the news that Notre Dame’s famous stained glass Rose Window and most priceless statues and artefacts survived the blaze, it’s some good news on a sad day.