To scan a 3D object, many methods are available. There are machines that physically touch the object from all sides and then calculates the shape of the object, but these are very expensive and space-consuming, if very accurate.
Non-contact methods include
- laser triangulation 3D scanning technology.
- structured light 3D scanning technology.
- laser pulse-based 3D scanning technology.
- laser-based 3D scanners.
Of these, laser systems are mostly used for scanning volumes, such as rooms, construction sites, or very large objects. These systems also cost a lot of money – a Leica laser scanner system is in the region of 50,000 €, but the accuracy of the system is nothing short of amazing.
For Haaga-Helia, such laser systems are not viable. Therefore our Lab acquired an Artec EVA structured light scanner, when a 30,000 € grant was made available to furnish the Lab. This scanner projects a light grid on the object being scanned, and deduces the form of the object from the deformations of the light grid. It also takes regular photographs, which makes it possible to add textures to the meshes, resulting in a lifelike digital copy of the object and not just the mesh. The accuracy of the EVA is around 0.1mm in three dimensions, and a scan of a teddy bear results in 300,000 vertices, so the resolution of the mesh is stunning.
The process of scanning is very simple, just point the device at the object and follow the screen to see that the distance to the object stays constant:
This technology is very simple. Given enough photographs of an object, the photogrammetry software is able to deduce the form and texture of the object. Usually 40 HD photographs are sufficient to do this. Photogrammetry software include Autodesk Recap, which is a pro quality system, Capturing Reality which is a more affordable solution, and open source solutions such as Meshroom.
At Haaga-Helia, students have a license for all Autodesk products, but they expire at graduation. The Lab has acquired student licenses to Capturing Reality, which is a very powerful photogrammetry tool. We also built our own HD webcam based system to automate the photography.