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Author Topic: 3D scanning for the rest of us.  (Read 3008 times)

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Offline EtchedPixels

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3D scanning for the rest of us.
« on: January 08, 2012, 11:43:18 PM »
I guess you'd probably get arrested for waving a Kinect on a pole around some of our stations but I found this really interesting stuff (if rather technical). Doing the equivalent of fancy 3D laser scanning with a Kinect and a PC.

http://vr.tu-freiberg.de/scivi/

"Knowledge has no value or use for the solitary owner: to be enjoyed it must be communicated" -- Charles Pratt, 1st Earl Camden

Offline 4x2

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Re: 3D scanning for the rest of us.
« Reply #1 on: January 08, 2012, 11:51:41 PM »
I guess you'd probably get arrested for waving a Kinect on a pole around some of our stations but I found this really interesting stuff (if rather technical). Doing the equivalent of fancy 3D laser scanning with a Kinect and a PC.

http://vr.tu-freiberg.de/scivi/
Clever so-and-so's !
It's quite obvious really - the xbox360 is effectively a games PC, all the connections are via standard PC inputs - ie USB etc... The kinect is really a USB 3D camera/scanner all in one... Genius !

or have i got it completely wrong ???  :smiley-laughing:
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Offline MikeDunn

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Re: 3D scanning for the rest of us.
« Reply #2 on: January 09, 2012, 01:22:06 PM »
Oh it's clever all right ... but lacking in detail ?  All the scans were - well, flat ?  Even the one of the robot didn't show much :(

But for a work-in-progress - impressive.

Offline Fratton

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Re: 3D scanning for the rest of us.
« Reply #3 on: January 09, 2012, 04:43:40 PM »
as much as i love kinect sports i have to say im suprised they havent used and widened kinect technology in use for PC yet,

imagine this but no need for gloves, the sensor just picks up your hands and off you go,,,

http://youtu.be/NwVBzx0LMNQ

given the way tablet tech is moving screen tech along the seethrough screen might not be all that far off either,,,

now this would be really cool

http://youtu.be/-KPhqy7ZwHU
Charlie.

Offline EtchedPixels

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Re: 3D scanning for the rest of us.
« Reply #4 on: January 09, 2012, 07:12:15 PM »
http://openkinect.org/wiki/Gallery

has a ton of demos (many very silly)
"Knowledge has no value or use for the solitary owner: to be enjoyed it must be communicated" -- Charles Pratt, 1st Earl Camden

Offline Flakmunky

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Re: 3D scanning for the rest of us.
« Reply #5 on: August 30, 2012, 05:25:34 PM »
The kinet is extremely low resolution; it uses a VGA webcam. I wouldn't imagine the resulting scan would be very useful.

In comparison, 3d laser scanners produce point clouds of millions of points. These can be tessellated but the resulting mesh is just plain nasty. The biggest problem is determining where the edges are. We worked on a city scanning project with a company that had 2 laser scanners mounted to a helicopter. The data was awful as the was just so bloody much of it!

I have worked with a handheld scanner which was really good as well as tripod mounted full colour scanners which are also good.

Photogrammetry may be an option. Try photomodeler.com...

Regards,

Tim
« Last Edit: August 30, 2012, 05:28:50 PM by Flakmunky »
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Offline EtchedPixels

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Re: 3D scanning for the rest of us.
« Reply #6 on: August 30, 2012, 06:11:37 PM »
The kinet is extremely low resolution; it uses a VGA webcam. I wouldn't imagine the resulting scan would be very useful.

See the examples and the actual research work. It's good enough for a lot of uses, especially as it's being moved so the point cloud generated is much much larger than the resolution.

No imagining needed - take a look at the results, apps and research papers!
"Knowledge has no value or use for the solitary owner: to be enjoyed it must be communicated" -- Charles Pratt, 1st Earl Camden

Offline Flakmunky

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Re: 3D scanning for the rest of us.
« Reply #7 on: August 30, 2012, 07:30:25 PM »
I have looked at the link you sent. Without examining the point cloud data first hand in a 3d package I can only imagine the quality and accuracy; the samples don't look great but given the cost of the equipment they are good. BTW I am fully aware of how they are building up a more detailed point cloud from a low res device.

It is impressive, but having worked professionally with a lot of scan data, even expensive high-end systems produce scan data that requires a *lot* of post cleanup work. The big problem is edge detection.

You missed the main point of my post (probably as it was almost a throw away comment at the end) and that was to highlight an inexpesnive, accessible technology that members of this forum could potentially use to build models of the real world that could be printed.

For those who are interested, photogrammetry constructs 3d models from multiple photographs of the same object but from different viewpoints. You need to identify common points on each photograph, e.g. The corner of a building, the top of a window frame, the ridge of a roof, etc, and the software will create a 3d model from that.

I used it quite some time ago and found it pretty good at creating models of basic geometric shapes such as buildings but not so great with more organic shapes.

Hth
« Last Edit: August 31, 2012, 07:52:27 AM by Flakmunky »
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Offline Rabs

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Re: 3D scanning for the rest of us.
« Reply #8 on: August 31, 2012, 09:47:40 PM »
I've been using one of these systems for a while now:
http://reconstructme.net/
I'm very impressed by the results.  The way these structured light depth sensing systems usually overcome the resolution limitation is to use small movements of the light source (and in the case of the kinect the detector too).  This allows sensing of a much larger number of points on the surface.  It does require quite a powerful computer to stitch all the data together but, as long as you move the kinect about a bit, you can do much better than the native resolution of the camera.  I recently did a scan of 1/14 model tractor and got approximately a 3mm resolution at 0.5m distance.  There is a limitation with the kincet, which is that the optics are optimised for sensing person-sized things at living room distances.  Some users of the ReconstructMe forum have been using cheap reading glasses taped to the front to improve the resolution for small objects.
Quite fun to play with but I've not found a 'useful' application for it yet!

Offline EtchedPixels

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Re: 3D scanning for the rest of us.
« Reply #9 on: August 31, 2012, 10:00:57 PM »
The big problem for a lot of the "useful" uses is that if you try and do it at a station or on the side of a railway line someone is probably going to arrest you , and explaining you are 3D imaging the canopy pillars will be fun
"Knowledge has no value or use for the solitary owner: to be enjoyed it must be communicated" -- Charles Pratt, 1st Earl Camden

Offline Rabs

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Re: 3D scanning for the rest of us.
« Reply #10 on: August 31, 2012, 11:04:04 PM »
Quite!
But coupled with a good 3d printing technology it might be useful for postboxes, phone booths and the like.  You're less likely to get suspicious looks there.

Offline Arrachogaidh

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Re: 3D scanning for the rest of us.
« Reply #11 on: December 23, 2012, 12:24:50 PM »
I guess there is no real need to be looked upon with suspicion if you were to make contact with the relevant Train Operating Company or Network Rail, explain what you would like to do and why and seek the necessary permission.

They aren't all ogres you know.....


 :claphappy: :claphappy:
(Sorry, but you are not allowed to access the gallery)

Offline Anthony Lloyd

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Re: 3D scanning for the rest of us.
« Reply #12 on: December 23, 2012, 06:40:54 PM »
I guess there is no real need to be looked upon with suspicion if you were to make contact with the relevant Train Operating Company or Network Rail, explain what you would like to do and why and seek the necessary permission.

They aren't all ogres you know.....


 :claphappy: :claphappy:
This is true ... my best advice if you were to be taking photographs of anything more than "a casual kodak moment"* that you go to the information point/ticket office (or station reception for larger Network Rail operated stations) and confirm that you are ok to do so. They will probably ask you to sign in and give you a load of safety information for contractors, and then sign out again, but the alternative I have experienced first hand was spending an hour and a half in the BTP offices at Manchester Piccadilly because I was taking photographs of mundane items like buffer stops, seats, monitor screens, clocks and empty track.

It  took me an hour and a half to explain that I was taking research photos for a computer game. Even then they deleted the "offending" images from my camera. Following day I went back and asked for permission to take photos and was given a blue Network Rail vest and escorted for almost 2 hours around the station where I made sure I took my time and took EVERY photograph I could, even the ones I didn't need.

From that day onwards I have always always contacted the station staff and never been refused - although I have been given a time limit if it was approaching peak period which is understandable. Bottom line is if they know you are there, and know what you are there for, you are not a security risk and you are an extra pair of eyes and ears.

Railway Enthusiasts - Network Rail

*other brands are available.
« Last Edit: December 23, 2012, 06:48:22 PM by Pengy, Reason: repaired link »

 

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