3d-scanner with Lego bricks, a Laser and Optics

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Disclaimer: LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this site.
The rendered images are made with POV-Ray. The pieces come from Lutz Uhlmann's LGEO library for POV-Ray.
The Java applet the show the models is based on a demoapplet for the Java Development Kit 1.2.


A laserbeam sweeps the object that is rotated (in reality, the object rotates slower, so we get more different passages). The light undergoes diffuse reflection. Some (small) fraction of the light hits a position sensitivt detector, and so we can determine the distance from a specific point to the point on the object. By simultaneously keeping track of the angles (rotation of object, direction of light), a 3d-image can be created.

Note. The laser beam itself is normally not visible, neither here, nor in space adventure movies. The use of laserlight is not necessary for this application, the important feature is the concentrated light dot.


A letter F
A paperplane
One lego brick
Two lego bricks

About the applet

Points: Measurement points that probably belongs to the object.
Plates: Measurement points that probably belongs to the object. Marked with triangles in a plane orthogonal to the ray of the incoming light. The lines indicate the incident ray.
Lines: Connected points. Every point has been assigned between 3 and 10 lines, as short as possible.
Triangles: Triangles drawn were the have been implied by lines.

If you have found anything strange, have a question, an idea or anything else, let us know:

E-Mail: Håkan T. J. (f96hajo@chalmers.se)
f96dafe at the server dd.chalmers.se

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