By projecting a pattern of light on an object and examining how it is distorted by the object’s shifting surface, 3D scanners can quickly record its shape and dimensions.
The scanner can be set up according to the kind of object the operator wants to capture. The eviXscan 3D Loupe+ from Evatronix, for example, uses two cameras which can be moved to any of 15 positions to capture small objects at very high resolution or large objects quickly.
The object to be scanned can be mounted on a software controlled turntable so that it can be scanned from several directions and the model views automatically assembled saving time in post processing. Other simple processes can be used for larger objects.
The cameras record the distortion of the projected light pattern on the surface of the object which is a function of its distance at a given point. This data is used to generate a mesh, which, in turn, is used to generate an STL file and other formats.
Meshes can also be used as a template for reverse engineering by generating an accurate representation of the object consisting of surfaces and solids used by CAD software.