3d laser scanner without a laser?

Hi all,

This may have already been done but in my short time searching I haven't found anything so thought I would put it here as if it has been done someone here would know.

So I will be getting a 3D Printer and started thinking about 3D scanners. I would like to try to build one as cheaply as possible so one of the DIY Laser scanners seems to fit the bill but there must be a way to reduce the cost of materials.

I began thinking about what we could get rid of and the first thought was get rid of the laser and use a bright light source instead, maybe through a slit. Then I though why couldn't you just use a shadow edge as your laser line? Place a bright light behind a barrier with a straight edge, the boundary between the light and shadow should act exactly the same as a laser, All you have to do is detect the edge.

A decent green laser can cost $50 or more whereas a bright LED light like a car headlight is as little as $3, runs on 12 volts and should surely be bright enough but I really don't know about these things, it just seems reasonable to my mind.

Do you think this will work? Has it been done already? Feel free to shoot me down and call me an idiot, I don't want to get my hopes up but I was thinking about printing a wally at some point as a gift for my son's school and if I could also provide a scanner without breaking the bank that would be a real bonus.

Keith

Ok so 22 views and no replies either means it is a stupid idea or nobody knows. I might give it a go anyway and see what happens.

MightyMouth Wrote:
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> Ok so 22 views and no replies either means it is a
> stupid idea or nobody knows. I might give it a go
> anyway and see what happens.

Patience glasshopper,..... some years ago there was a shadow scanner using a pencil in front of a light, but blowed if I can remember much about it. think the code was available, keep searching.

Edit... first hit on google [www.vision.caltech.edu]

Edited 1 time(s). Last edit at 09/26/2013 03:30PM by johnrpm.

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Random Precision

Thanks,

After some more searching today I found that David-Laserscanner apparently can use both a thin line shadow or a reveal shadow where you block the light and slowly reveal the light. Unfortunately they want quite a lot of money for the full software. Might try the free edition to see how it goes. That caltech link says the technology is patented and the rights have been sold. How can you patent something so obvious that a complete numpty like me thought of it the first day I considered the problem.

3D scanning has come a long way, and lots of different approaches, some with source code, I bought an early version of DAVID, but have not used it much, bought a cheap kinnect from ebay, but do not have a good enough
gpu to run skanect very well, parsley might be worth looking at, but uses a laser I think, i bought some lasers from the pound shop.

P.S I am the numpty round here,.... I think I might patent the wheel unless someone has already done it.

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Random Precision

... David Laserscanner is best used in combination with a Beamer for "Structured Light Scanning" - made some really high resoultion+accuracy scans with reducing optics mounted to the beamer and to the camera ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

MightyMouth Wrote:
-------------------------------------------------------
...
> I began thinking about what we could get rid of
> and the first thought was get rid of the laser and
> use a bright light source instead, maybe through a
> slit. Then I though why couldn't you just use a
> shadow edge as your laser line? Place a bright
> light behind a barrier with a straight edge, the
> boundary between the light and shadow should act
> exactly the same as a laser, All you have to do is
> detect the edge.

Principle is sound but the problem is with cheap
cameras that do not have enough dynamic range to
capture good image of both bright and dark side, so
texture capture will be problematic.

There is a video on Youtube showing "slit scanning"
with bright light, scanning quality was good.


>
> A decent green laser can cost $50 or more whereas
> a bright LED light like a car headlight is as
> little as $3, runs on 12 volts and should surely
> be bright enough but I really don't know about
> these things, it just seems reasonable to my mind.

You can get focusable red laser line generator for
less then $5, a tad more then your LED.

>
>
> Do you think this will work? Has it been done
> already? Feel free to shoot me down and call me an
> idiot, I don't want to get my hopes up but I was
> thinking about printing a wally at some point as a
> gift for my son's school and if I could also
> provide a scanner without breaking the bank that
> would be a real bonus.
>

It works, it was done so no problem :-)
Just build it out of what you have and see how it works.