A 3D scanner is a device that analyses a real-world object or environment to collect data on its shape and possibly its appearance. From that collected data it can then be used to construct a digital three dimensional object.
Many different technologies can be used to build these 3D-scanning devices; each technology comes with its own limitations, advantages and costs. The purpose of a 3D scanner is usually to create a point cloud of geometric samples on the surface of the subject. These points can then be used to extrapolate the shape of the subject.. If colour information is collected at each point, then the colours on the surface of the subject can also be determined.
figure 1.1 A 3D model scanned from a human model
Scanners have several different technology, mainly it uses a photogrametry technique, or using a structured light technology, laser technology, or a combination. it sometimes employ several different accesories to help maintain integrity and expanding its capabilities. The Shining Einscan series desktop and handheld 3D scanner below relies on structured light technology and it is used as an entry level scanner for many application and industries.
When do you need a precision scan and sometimes the model is hard to scan, you can use a laser-based technology to overcome some of the limitations of scanning a big and hard-to-scan objects. these metrology scanners is used mostly for reverse engineering and inspections. you can see Shining 3D's metrology scanners below.