The 3D data acquisition of an object with a white light scanner or a fringe projection system takes place in the following sequence: After the 3D scanner, the measuring object, and as the case may be a turntable or a robot for an automated acquisition, have been set up, the sensor components (cameras, projector) are calibrated.

This is followed by the digital measurement of the object, in that the projector projects a sequence of fringe patterns (here: gray code procedure combined with phase shift technique) onto the measuring object, whereby each object displays an individual fringe pattern sequence in accordance with its contour. The system cameras capture this projected fringe pattern at a predefined viewing angle, while the individual projection varies for each object, and even for each view of the object. Depending on the application, either one or two cameras are used. When necessary, the 3D digitization is performed fully automatically by adding a turntable or robot which is synchronized with the measurement process.

An individual measuring sequence is completed within approximately one second; depending on the complexity of the measuring object, the entire measuring process takes between a few seconds and several minutes. The process is completed once the object has been completely digitized, i.e. individual images of all sides of the object have been captured and automatically saved. Within a matter of a few seconds, the computer then calculates the 3D data of the measuring object by aligning the individual captures by reference to the respective object geometry or by aid of index marks which prior to the data acquisition have been attached to the object.

The result initially is a so-called point cloud which is then – depending on the measuring task in hand (e.g. reverse engineering, rapid prototyping) and the aid of respective specialized programs - converted into a thinned net of triangles, referred to as the ‘mesh’. It is in this step of the process that for instance the surfaces are smoothened, or that the measurement noise is reduced and the data volume is decreased, without the overall data quality being compromised. The exact three-dimensional replica of the object is available as a data set in various formats and can be used for any type of further processing, e.g. with a CAD / CAM program.

The measuring volume captured by a white light scanner ranges from a few millimeters to about one meter. Yet, by combining the aforementioned method with another measurement strategy, the photogrammetry, considerably larger free form areas can also be captured at the highest level of detail – the spectrum of three-dimensional digitization ranges from smallest injector nozzles all the way up to meter high building structures.