Briefly about 3D scanning
So you might be a skilled 3d modeler, but what can you do, when simply reverse engineering the reality is not enough or it just takes too much time? You use a 3d scanner! But how do we get a real life object into the computer?
There are more kind of technologies available for 3d scanning. Basically we distinguish contact based and contactless 3d scanning. The former works like the old school children’s party game, when a blindfolded participant has to tell what he or she is holding just by touching the given object. More scientifically speaking, a probe attached to an articulated arm is being run along the surface of the object.
The more popular ways of 3d scanning don’t include direct contact with the subject. For example in laser triangulation a laser dot is projected onto the subject and depending on the scanned object’s shape, the projected dot will appear in different positions in the field of view of a camera looking from a slightly different angle.
In a somewhat similar technique called structured-light, a whole pattern is being projected which viewed from the sides looks distorted on the surface of the subject, giving the processing computer a precise idea about the shape of the object.
Another famous method is photogrammetry. During this process the 3d shape is calculated from multiple photographs taken from different angles. Note, that sharp and evenly lit photos are best used.