The Basilica of St Denis is recognised as the earliest masterpiece of monumental Gothic art. It is imprinted in the genes of the city of St Denis which developed around it. A classified historic monument, it is one of the leading heritage sites of the Paris region.
Inspection of the rose window of the south transept revealed significant deformation. For the regional organisation responsible for heritage matters, the DRAC Ile-de-France, it was important to act fast. A conservation and renovation programme was set up for the south transept as a whole. Numerous surveys were required before work could begin.
The deformation analysis was performed using a point cloud of the rose window. The high density of data captured (one point every 5 mm) enabled us to map the departures from the correct plane of the window extremely graphically. Thanks to this method of portrayal, we rapidly identified the sources of the various distortions present
This analysis was carried out using our own CloudSurfer software.
For the production of the plots we used a method combining laser scanning and photogrammetry: