3D scanner: 3D scanning implies analyzing thereal-world environment or objects for collecting data on their appearance, i.e.color and shape. Digital 3D models can be constructed from the data collected.Such devices are being used by the amusement industry extensively for producingvideo games and movies. This technology is more widely used in reverseengineering, industrial design, prototyping, keeping records of culturalartifacts, and computer vision. A number of technologies have been used forbuilding the three-dimensional scanning devices. Every technology haslimitations, costs, and advantages.

Functionality: The idea behind using athree-dimensional scanner is creating a Point Cloud of the Geometric Samples onthe subject's surface. The subject's shape can then be extrapolated by usingthese points. If information regarding color is gathered at every juncture, thedetermination of colors on subject's surface can be easily done. 3D scannersshare analogy with cameras. If one tries to define a Spherical CoordinateSystem wherein the origin would be the scanner and vector would be drawn fromfront of it such that ¸=0 and ¢=0, then every point in picture would beassociated with ¸ and ¢. Combined with distance that corresponds to r component3D position of every point in picture is described by the sphericalcoordinates.

Technology: 3D scanners consist of two types-non-contact and contact. Non-contact three-dimensional scanners could bedivided further into 2 major categories- passive and active scanners.

Non-Contact Active: Some light or radiation is alwaysemitted by active scanners. It is advised to detect the reflection of thislight, as it would help in locating environment or an object. The kinds ofemission possibly used include x-ray, ultrasound, or light.

Contact: Contact three-dimensional scanners locatethe subject by the way of physical touch. The best example of contactthree-dimensional scanner is a CMM (Coordinate Measuring Machine). It is widelyused in manufacturing processes due to its precision. However, it has adisadvantage that contact with object to be scanned is required. The targetobject might get modified or damaged by scanning. Historical artifacts, inparticular, have to be specially taken care of.

3D Prototyping: 3D prototyping is the subsetof rapid prototyping. The basic advantage of 3D prototyping is that numerousmaterials can be used as base materials. It involves taking of virtual designsthrough CAD (computer-aided design) or Animation Modeling software,transforming them into virtual, thin, and horizontal cross sections, and thencreating every cross-section in the physical space, 1 by 1 till the model getscompleted.

It should be noted that STL File Format is the interfacebetween machines and CAD software. This interface carries out the approximationof shape of an assembly or part by making use of triangular facets. Surfaces ofa superior quality are produced by smaller facets. 3D prototyping is believedto be the 'next level' equipment by most of the experts of this field. Pioneercompanies are striving to master the technique. The conservative prototypingmachines cost around 25000 pounds, as per the study conducted in the year2005.  

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