Structured light 3d scanner from siggraph.

Re: Structured light 3d scanner from siggraph.

Postby MagWeb » Mon Jan 24, 2011 5:24 pm

Hi,

now I finally found a way to get pointcloud data from this scanner into DAVID and use DAVID to build a mesh from those data:

This scanner´s calibration "sees" the object right along the z-axis.

In Blender:
-To get the resulting wrl file to DAVID, load it to Blender using the " X3d+VRML97(.x3d ,.wrl) " import filter as Chris posted above (Meshlab breaks here).
-Move the pointcloud to the origin using (again Blender) Object/transformation/objectdata to origin.
-export as OBJ without the default rotation (disable in the export dialog). e.g. Scan.obj

In DAVID:
-calibrate the cam you used with the siggraph scanner .
-close DAVID and open config.xml in the DAVID directory.
-go to the calibration section and set
Code: Select all
<cx>400</cx>
<cy>300</cy>
where cx and cy are the half of your set cam resolution.
and
Code: Select all
<nx>-1</nx>
<ny>0</ny>
<nz>0</nz>
<ox>0</ox>
<oy>-1</oy>
<oz>-0</oz>
<ax>0</ax>
<ay>0</ay>
<az>1</az>
<px>0</px>
<py>0</py>
<pz>-2121.32034355</pz>
this makes DAVID look right along the z axis, where pz is the virtual distance to the cloud. You may in- or decrease that value if the finally loaded mesh is cut off or to small .

-save the config.xml
-Open DAVID again, switch to scanning and load the scan.obj
-When you save it from DAVID or open it in its viewer, DAVID meshes the pointcloud.

Gunter
Attachments
DAVID_SIG2.jpg
MagWeb
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Re: Structured light 3d scanner from siggraph.

Postby nickg4000 » Thu May 05, 2011 10:29 am

Hi

I'm having trouble with getting the depth of field right similar to beedeeuniko a few posts back. i.e. scans looks right from the camera's perspective but are squashed by about 1/3 along its optical (z?) axis.

I've tried calibrating with the chequered board at angles to both the camera and projector but that only helps so far.
Any suggestions other than stretching the point clouds back along the z axis in Blender or some such?

Thanks

nick
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Posts: 12
Joined: Tue Mar 08, 2011 12:39 pm

Re: Structured light 3d scanner from siggraph.

Postby schueler » Mon Sep 19, 2011 3:02 pm

Hi all,

I found a way to modify the files to load them in MeshLab. As written by vectral in a post before the problem is that there are no faces. So you just have to create a fake face manually:

For example you change the end of your file from
Code: Select all
    0.203922     0.325490     0.235294
    ]
   }
  }
}

to
Code: Select all
     0.203922     0.325490     0.235294
    ]
   } coordIndex [1,2,3]
  }
}

you will have a dummy face between the first 3 vertexes and it loads fine with MeshLab.
schueler
 
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Re: Structured light 3d scanner from siggraph.

Postby schueler » Mon Sep 19, 2011 3:08 pm

Hi all,
... it is even simpler: At the beginning of the file just change "IndexedFaceSet" to "PointSet". Then everything works fine with MeshLab, even the color.
schueler
 
Posts: 2
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