Why 3D scanning?
A large number of companies on the globe are depending on reverse engineering to quickly launch new products ahead of their competitors. Basically, reverse engineering involves reproduction of a product(s) either within the company or from other manufacturers. To accomplish this, all data (such as dimensions, color, texture, composition, etc.) of the original product or part need to be examined and documented. This data is then fed into manufacturing machines for the purposes of reproduction. One aspect of such data is 3D models. Acquiring such data is a very difficult task and that is where 3D scanning technologies come in handy.
The sole purpose of a 3D scanner is to generate 3D models by examining an existing product or part. The surface of the generated 3D model normally consists of a point cloud of the geometric sample(s). Such points can then be used to reconstruct the object through extrapolation of the shape so that the new product is different from the original object.
3D scanners use various cameras that have a cone-like viewing point. Like any camera, 3D scanners only collect information about surfaces that are not obstructed from the view (camera). 3D scanners are known to collect distance information about a surface as long as such surface is not obstructed. As a result, the 3D picture generated describes information related to the distance to a surface at each point. As a result, the 3D position of each and every point in the picture is identifiable.
In many instances, a number of scans from different directions are required to capture the features and information of each surface within an object. All the scans are then referred from a common reference system through a process referred to as alignment or registration. They are then merged in order to create 3D models which can be presented using 3D CAD software such as Solidworks, Inventor, CATIA, etc. Using these 3D models, engineers can then improve them or even add features according to the functional requirements of the product. This, in turn, saves the designers from the hustle of acquiring all the information about the product in order to improve or reproduce them. As a result, redesigning or reproduction step is shortened culminating in the quick launch of products in the market and thus improved competitiveness.
What are the existing 3D scanning technologies?
There are a number of 3D scanning technologies. The general classification looks at such technologies as contact and non-contact. Additionally, non-contact technologies can be classified as active or passive technologies. As the names suggest, contact technologies involve physical touch between the probe and the object. A good example is the CMM (coordinate measuring machine). With non-active scanners, emissions such as light, x-ray, or ultrasound are used to probe the surfaces of the object while reflecting or radiating through the object to acquire data. Examples include Time-of-flight scanners and triangulation scanners. Another category is hand-held-scanners where a technician literally holds the scanner while collecting the information. In all 3D scanners, transmission of data to the computers is by cables or even wirelessly.