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can't succeed when projecting from below the camera...

Problems, solutions and discussion about scanning with a video projector and stripe patterns.

can't succeed when projecting from below the camera...

Postby Strob » Sun Aug 01, 2010 7:31 pm

I am trying to do 3d scan simulation in 3D. So my contrast is pefect. When I project from top of camera it works, but when I try to project from below the camera at the same distance, I am getting two lines and David send me an error telling "left and right laser llight not on a plane"...
anyone has an idea about that?
Image
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Re: can't succeed when projecting from below the camera...

Postby Bongobat » Mon Aug 02, 2010 12:56 am

Hi,

I think your problem is in your simulation. The projection map is probably repeating itself causing the double line. David will not work with two lines.

Greg
DealExtreme red line laser, Microsoft Lifecam HD-5000
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Re: can't succeed when projecting from below the camera...

Postby Strob » Mon Aug 02, 2010 2:09 pm

I can't find what could be wrong in my simulation. The pattern does not seem to repeat itself. My pattern is projected by a light and it is not tiling. I just duplicated the same light that is used for the working top projection.

bottom projection (not working):
Image



top projection (working):
Image
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Re: can't succeed when projecting from below the camera...

Postby Simon » Tue Aug 03, 2010 7:47 pm

Hi Strob,

I guess there is somthing wrong with your patterns. If you post all 12 camera images (e.g. in a ZIP file) we can reproduce the problem and can try to find the error.
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Re: can't succeed when projecting from below the camera...

Postby pottersfriend » Tue Aug 03, 2010 8:24 pm

Just a guess here since I'm not too experienced with this but it looks like your pattern projection isn't correct. Look at the orientation of your dots (circled red - should look similar to the blue) compared to your successful image. Sorry for the poor MS Paint picture but I think you get the idea. Assuming that your panel is parallel to the blue lines then the dots should be also. It doesn't look like they are in the top (failed) image but are in the bottom (successful) image.

Just my 2 cents.
Darin
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Re: can't succeed when projecting from below the camera...

Postby Strob » Wed Aug 04, 2010 2:59 am

ouuuuuuuuuuuuuuupss!

Sorry I just dicovered my mistake... You are right Simon! I had only 11 images for the bottom projection!!! :oops:

Now it's working! I think I will order my projector tonight!

got my two passes!!! so excited! Your are a genius! It works!
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Postby hal » Wed Aug 04, 2010 12:03 pm

Well Strob,

so seems that we can see something of exciting from you, before David 3 will be released... Great!
Ok, looking at your scans, you can avoid all the "bad links" of the mesh, that David create with default values.
As you can see, along the edges, there are a lot of "long" trinagles. This happen because the Threshold value is at 0.083. Try to reduce it (I work with 0.025-0.015) and the software calculate triangles only between the near vertex included into this threshold value. The long, deformed, poligons aren't a correct survey of your object, and may introduce a little (very little) error when you align all the scans.
If you want to reduce tha bad links, modify its value in the Advanced Settings ->Laserscanner -> TriangleMeshComputation -> DepthThresholdFactor.

Good work,
Mattia
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Re: can't succeed when projecting from below the camera...

Postby Strob » Wed Aug 04, 2010 3:03 pm

I hope!

I finnally ordered that HD projector:
BenQ W1000 HDTV 1080P DLP Projector 1920X1080 2000 ANSI 3000:1
http://www.ncix.com/products/index.php? ... omoid=1001

can't wait to do my first real life scan!
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