Scanners - 3D Printing: The Basics and Beyond - page 49

Scanners
A 3D scanner captures an object and saves it as a “point cloud”. The point cloud can be con-
verted to a CAD model with software such as Geomagic etc. After saving an STL file (or
other format) the scanned object may be recreated by a 3D printer.
“ Time-of-flight ” and “ Triangulation ” 3D scanners use laser light to probe the object. Time-
of-flight scanners are suitable for very long distances, like miles or kilometers, and large
objects like architectural structures. Triangulation scanners works best with small distances
and have a much higher accuracy than time-of-flight scanners.
“ Structured light ” scanning is becoming increasingly popular for use with 3D printing.
This technology uses projected light patterns and a camera to capture 3D objects. Mi-
crosoft's Xbox Kinect was based on structured light sensing.
There is also a form of 3D scanning that does not send out any light, it is called “ Passive
scanning ” in the simplest form it only uses a digital camera that takes several shots which
are fixed and configured afterwards in a computer program in order to render a 3D file. The
free program Autodesk 123D Catch works this way.
In the medical field CT (Computed Tomography) and MRI (Magnetic Resonance Imaging)
have been used for a long time. These X-ray technologies are also a form of 3D scanning.