  Precise 3D measurements of rigid surfaces are desired in many fields of
application like quality control or surgery. Often, views from all around the
object have to be acquired for a full 3D description of the object surface. We
present a sensor principle called "Flying Triangulation" which avoids an
elaborate "stop-and-go" procedure. It combines a low-cost classical
light-section sensor with an algorithmic pipeline. A hand-guided sensor
captures a continuous movie of 3D views while being moved around the object.
The views are automatically aligned and the acquired 3D model is displayed in
real time. In contrast to most existing sensors no bandwidth is wasted for
spatial or temporal encoding of the projected lines. Nor is an expensive color
camera necessary for 3D acquisition. The achievable measurement uncertainty and
lateral resolution of the generated 3D data is merely limited by physics. An
alternating projection of vertical and horizontal lines guarantees the
existence of corresponding points in successive 3D views. This enables a
precise registration without surface interpolation. For registration, a variant
of the iterative closest point algorithm - adapted to the specific nature of
our 3D views - is introduced. Furthermore, data reduction and smoothing without
losing lateral resolution as well as the acquisition and mapping of a color
texture is presented. The precision and applicability of the sensor is
demonstrated by simulation and measurement results.
