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My goals for this project were as follows:
Make scanner which
*could accurately and correctly produce computer models in 3D
*would work for objects under 1' x 1' x 1' in size
*wouldn't cost more than $20 on the project (Materials I have lying around don't count towards the cost, but including these materials, the scanner still costs only about $100.)
The final product works pretty well, and I hope to improve it's usability in the future by further automating it's performance and tweaking the software.
Make scanner which
*could accurately and correctly produce computer models in 3D
*would work for objects under 1' x 1' x 1' in size
*wouldn't cost more than $20 on the project (Materials I have lying around don't count towards the cost, but including these materials, the scanner still costs only about $100.)
The final product works pretty well, and I hope to improve it's usability in the future by further automating it's performance and tweaking the software.
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Signing UpStep 1The Basic Idea...Overview
In order to locate a point in 3d space, we need to describe one of several things. The simplest would simply be to give three numbers to describe it's position relative to another point in space. This is the format used by most computer models. Another way to describe the point would be to use three planes, or a plane and a line. What you'll see is that it's easiest to describe points in the third way, then convert them to the first to save them to standard format. So the question becomes, how to find the plane and the line? As it turns out, the first question is in the hardware, and the second in the software.
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~Will
is it possible to see your notes or to have little diagrams or pseudo code for the triangulation part ? I think there are few people/hobbyists that can buy matlab. All 3d scanners use this and I despair to see a simple implementation.
I'll try to do a proper write up over the weekend, or barring that after finals. Feel free to comment here or PM if you have any specific points of confusion.
~Dentroman (aka Will)
The beers you could buy with the spare Matlab license money would go a long way towards dulling the pain of learning yet another language. In fact you'd probably need to go to rehab... :)
http://www.ekaggrat.net/explorations/laser-scanner/
I am looking for a scanner that can scan the bottom of the foot, and use that information for carving insoles by a cnc system. Are you interested in making a prototype and develop the software for that? If you are, we can discuss how much it would cost.
In a later build, I might add a turntable, and then I could scan multiple axis, but that isn't really necessary to get a scan.
The light from the laser beam forms a plane, at least where the camera is concerned. Try drawing a cross section of an object on a piece of paper, then turning the paper so it's at an angle: the cross section will be distorted, but so long as you know that it is on the plane of the paper, it's fairly easy to work out the shape.
The computer analyses the curve of light it sees to make the points in this same way.
Your observation about reflections is a good one: I quickly discovered that reflective objects do not work well with this method, and that the light must be just right to get good quality scans.
Thank you very much for going to all the trouble of explaining the system to me. I think I must be getting senile from not seeing it immediately; after all, you repeatedly said that the detector was a camera, but my mind converted it to "photodetector." I can see that your camera setup would work perfectly. Thank you for your patience with me.
For a couple of years, I have been working on an acoustic scanner with a single microphone that I move in the x and y directions to scan an acoustic field. I got so blinded by that approach that I couldn't see yours. Very sorry.
Thank you again for your interesting instructable.