3D scanning is a method of creating a computer model directly from an object in one of two ways: either by using lasers to map 'points' on the object or by capturing thousands of images to work out its geometries. The resulting CAD model can then be used to print from directly, or as a guide from which to build a model that needs to be adjustable. It is this second method that LUMA employed.
The glasses from which we were making a CAD model had lots of curves, which made them difficult to measure as there seemed to be no clear reference point from which we could work. The image (right) shows one of the glasses' side panels; the 3D scan data is shown in red and our CAD model in grey. This scan data allows us to easily see where the surface should travel, something that would have been almost impossible to work out with calipers!
3D scanning does have some downfalls however and the main one that we encountered was the accurate reproduction of small features: clips, little holes, ridges etc. These became quite blurred when only a few millimeters in size and still needed to be measured by hand. Still, 3D scanning was an invaluable tool for us and the SMART glasses project would have taken a lot longer without it.