Subject:
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Re: Scanner / Terrain Modeller?
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 19 Jan 2001 16:26:11 GMT
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Original-From:
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Tim Hatch <vbq@SAYNOTOSPAMmyrealbox.com>
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Viewed:
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604 times
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I, personally, would take some sort or range sensor and pass it over the
model in a grid fashon. You could then take that data into a computer and
wouldn't require you to have a camera. I can provide help if you want it.
This might be somewhat similar to the laser-rangefinder device (I know, that
does need a camera).
Tim
----- Original Message -----
From: Steve Baker <sjbaker1@airmail.net>
To: Lego Robotics <lego-robotics@crynwr.com>
Sent: Friday, January 19, 2001 10:04 AM
Subject: Re: Scanner / Terrain Modeller?
> Gary Mullen wrote:
>
> > Well I was talking about creating a device using LEGO which would "scan"
> > an object. When I say scan, what I actually mean is take measurements • of
> > the object. This may involve using light or sound or just by touching • the
> > object. Either the scanning device would rotate around the object or it
> > would rotate the object, using this method we could create a 3D model of
> > the image.
>
> Oh! I see.
>
> OK - then using the Lego camera should be a one place to start.
>
> You'll need the power of the PC to turn that into 3D though.
>
> There has been some work on the business of turning a LOT of 2D images
> (taken with a video camera or similar) into 3D - but your software,
> math and image processing skills had better be VERY strong if you
> are going to attempt it.
>
> I went to the SigGraph 2000 conference last year and attended a
> half day course on the subject - I could probably dig out the
> references if you are truly serious about doing 3D reconstruction
> software - but unless you are really pretty skilled in this kind
> of thing, it's going to be a major effort to turn the available
> literature into a working program.
>
> The whole Lego part will be about 0.01% of the project!
>
> This stuff is all rather new and 'researchy' - so I doubt that
> there are any off-the-shelf solutions.
>
> On the other hand, there are other ways to do 3D reconstruction.
>
> One is to use a laser that scans up and down to create a vertical
> plane of laser light. When you shine that onto a 3D object in a
> darkened room, your camera will see a distorted line where that
> invisible 'plane' of light slices through the 3D shape. If you
> can use your camera to capture the shape of that line, then by
> spinning the object and repeating the procedure every few degrees
> of rotation, you get a radial map of the shape of the object.
>
> The problem is that this really only works for fairly round,
> smooth surfaces and it doesn't work well for complex objects
> with holes and such in them. That technology has been used
> for scanning people's faces and things like that.
>
> Anyway, however you measure sample points on the object, you
> still have to connect them up to make a 3D object - even that
> is far from trivial. Delauny triangulation is the most popular
> algorithm for doing this.
>
> This is a *huge* and complex topic though.
>
> --
> Steve Baker HomeEmail: <sjbaker1@airmail.net>
> WorkEmail: <sjbaker@link.com>
> HomePage : http://web2.airmail.net/sjbaker1
> Projects : http://plib.sourceforge.net
> http://tuxaqfh.sourceforge.net
> http://tuxkart.sourceforge.net
> http://prettypoly.sourceforge.net
> http://freeglut.sourceforge.net
>
>
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Message is in Reply To:
 | | Re: Scanner / Terrain Modeller?
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| (...) Oh! I see. OK - then using the Lego camera should be a one place to start. You'll need the power of the PC to turn that into 3D though. There has been some work on the business of turning a LOT of 2D images (taken with a video camera or (...) (24 years ago, 19-Jan-01, to lugnet.robotics)
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