On the evening of April 15th, Paris time, the landmark of Paris, Notre Dame de Paris, was destroyed in a fire. The wooden spires of up to 80 meters collapsed in smoke, plunging people around the world into sorrow. Fortunately, there are a few things that can make the public feel a little relieved. First of all, the fire was not caused by intentional arson. Second, the fire has been basically extinguished, and most of the remaining buildings and artifacts in the cathedral have been protected. Finally, in the long run, the losses already caused may not be too great. "The bell tower of Quasimodo" is still there, and many people who are interested in Notre Dame are slightly relieved.

A person's research can make this thing look less bad. Art historian and historical modeler Dr. Andrew Tallon conducted a comprehensive study of Notre Dame in 2015, creating a digital archive of the building. Despite the long history of Notre Dame de Paris, there is very little information about the architects and designers who built the building. Therefore, Talon hopes to decrypt this ancient building through laser scanning technology.

The laser modeling technique used by Talon refers to the use of a laser to "shoot" the Notre Dame, mount the scanner on a tripod, and then measure the distance between the scanner and each point the laser hits. Because each point represents a different distance, by analyzing the millions of points, Talon can learn how the Notre Dame expands and contracts in daylight, and how it changes over a longer period of time. Combining the “point data cloud” generated by the laser scanner with the pictures taken on site, Talon established a fine model for the underlying structure and the design of the Notre Dame to determine where the architect had deviated from the original plan or because of the ground conditions. Unstable and stopped working.

Talon described the technology in detail in an interview with National Geographic. "I have to build a target network that represents the location points in space. After defining the density of the scan (the resolution of the scan), Release the laser. After emitting a beam, it measures the time it takes for the beam to travel from hitting the target and the time it takes to return to the target."