A simple and affordable 3D scanner is designed in this paper. Three-dimensional digital models are playing an
increasingly important role in many fields, such as computer animate, industrial design, artistic design and heritage
conservation. For many complex shapes, optical measurement systems are indispensable to acquiring the 3D information.
In the field of computer animate, such an optical measurement device is too expensive to be widely adopted, and on the
other hand, the precision is not as critical a factor in that situation. In this paper, a new cheap 3D measurement system
is implemented based on modified weak structured light, using only a video camera, a light source and a straight stick
rotating on a fixed axis. For an ordinary weak structured light configuration, one or two reference planes are required,
and the shadows on these planes must be tracked in the scanning process, which destroy the convenience of this method.
In the modified system, reference planes are unnecessary, and size range of the scanned objects is expanded widely. A
new calibration procedure is also realized for the proposed method, and points cloud is obtained by analyzing the shadow
strips on the object. A two-stage ICP algorithm is used to merge the points cloud from different viewpoints to get a full
description of the object, and after a series of operations, a NURBS surface model is generated in the end. A complex toy
bear is used to verify the efficiency of the method, and errors range from 0.7783mm to 1.4326mm comparing with the
ground truth measurement.