There's a lot of speculation in this article. I don't know what documentation exists of Notre Dame's roof structure, and from the way these (foreign) experts ar

There's a lot of speculation in this article. I don't know what documentation exists of Notre Dame's roof structure, and from the way these (foreign) experts are talking, they don't know either. A point cloud scan is a particular kind of record, one which doesn't include information about construction techniques or materials. It's good for capturing geometry, to the point of excessive accuracy. This situation is a bit like analysing a plate of food using a mass spectrometer. The data is incredible but it doesn't overlap at all with what went on in the kitchen or on the farms where the food was grown. It doesn't tell you how to recreate the meal. Point clouds are nice to have, but they are really a souped-up form of photogrammetry, and not equivalent to a survey performed by an expert human.