About 3D digitizing

3D digitizing is a procedure used to build a digital 3D copy of a physical 
surface. The main difficulty resides in obtaining the actual shape of the 
surface, that is, the volume the surface occupies in space. In the 3D 
optical digitizing process, the digitizer acquires range images (similar to 
contour maps) that are processed by modeling software and converted 
to point positions in space. All of the surface visible by the sensor can 
therefore be digitized in one shot.

Other methods exist to acquire the shape of a surface. Some others are 
also optical, such as scanning (often done using lasers), where acquisition 
is sequential, one point or one line at a time. Others are mechanical and 
use, for instance, tactile sensors. The technology in InSpeck’s digitizers 
enables them to obtain, all at once, not only the shape of the surface seen 
by the camera, but also the color information (texture), which is automatically 
fitted to the surface. This is all done without contact and in a short time, 
which makes it well suited for the digitizing of human beings.

The global procedure to obtain a complete digital 3D model from optical 
digitizing involves first acquiring a variety of partial views of the surface, as 
seen from a selection of angles, in order to cover all the surfaces of the object. 
For instance, when digitizing a head, the usual procedure would be to acquire 
7 partial views, 2 of the front, at an angle, 1 on each side, for each of the ears, 
2 of the back, again at an angle, and finally one of the top. Each of these views 
becomes a partial 3D model, and each has its own texture. These partial models 
are brought into a common system of coordinates and then registered one with 
the others to reproduce the overall shape of the object. They are then merged to 
produce a single polygonal model that includes all the surfaces seen during the 
digitizing process. The texture of each partial model is also merged to form a 
single texture for the merged model, that results in a final complete 3D model, 
which can be used in the following applications: e-commerce and web publishing, 
film special effects, video games characters, bio-medical research, etc.