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Misalignment of meshes

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

Misalignment of meshes

Postby luisg » Thu Sep 04, 2014 1:51 pm

Hi, I'm trying to scan a large relief and have alignment problems with the meshes. The pattern I used is 240 mm, the distance between the projector and camera is 33 cm and the distance between the scanner and the relief is 100 cms. I tried to calibrate it several times and although it gives me correct calibration then directed not align well. Can you help me ?.

Thank you.
Attachments
2014-09-04_13-55-44.jpg
2014-09-04_14-03-44.jpg
2014-09-04_14-45-56.jpg
www.digitalizacion-3d.com
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Re: Misalignment of meshes

Postby JDM Dyno » Thu Sep 04, 2014 2:35 pm

what type of alignment are you using? Have you tried free / contact pair alignment? like in this viewtopic.php?f=7&t=6215
Camera's: 2 x DFK 42BUC03 Duel Camera,
c615 modified with Computar megapixel lens
lenses: 2 x Pentax 12mm, 2 x Computar 8mm
Optoma ML300 Projector
Turntable

www.jdm-dyno.co.uk
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Re: Misalignment of meshes

Postby luisg » Thu Sep 04, 2014 8:02 pm

Hi JDM Dino, I'm using the free alignment and I've also tried the contact alignment pairs, but this last bit. Tomorrow I'll try more by this method. Scanning had much smaller things and had not had this problem. By the way I use the SLS2. I will read the link.

Thank you !!!
www.digitalizacion-3d.com
luisg
 
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Re: Misalignment of meshes

Postby JDM Dyno » Thu Sep 04, 2014 8:16 pm

your scans look very good and lots of detail so if you pick a point with a definite shape contact pair should work, if you like you could send me some scans and I'll have a go see if I can find a good point for you.

I've highlighted some points I would try,
david forum 2.jpg


Hope this helps!
Camera's: 2 x DFK 42BUC03 Duel Camera,
c615 modified with Computar megapixel lens
lenses: 2 x Pentax 12mm, 2 x Computar 8mm
Optoma ML300 Projector
Turntable

www.jdm-dyno.co.uk
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Re: Misalignment of meshes

Postby luisg » Mon Sep 08, 2014 11:55 am

Hi JDM, I read the post and tried the contact alignment pairs, I greatly improved the alignment but still I continued to have problems with alignments. I have not gotten scanned overlap perfectly but it sure will improve with practice. Thanks for your advice and your offer to send you files to test them.

In the following messages left pictures of work and for wrong alignments. For my first great relief, I'm happy with the end result although it has numerous errors 3d model. Gaps, noise, waves etc.

Slowly I'm learning. I have not taken a great resolution that was not necessary. And because the file would have much size. The holes are not closed.

The relief is 2 m. x 1.25 m.

Pattern: 240 mm.

Final Resolution: 1.22 mm.

Obj end Size: 251 MB.

Triangles: 5778618


Final Resolution: 0.85 mm.

Obj end Size: 577 MB.

Triangles: 13116269

Thank you!
Attachments
DSCN3152R.JPG
Original Relief
2014-09-08_12-48-30.jpg
3D Model
2014-09-08_12-55-38.jpg
Detail
www.digitalizacion-3d.com
luisg
 
Posts: 17
Joined: Fri Aug 08, 2014 8:33 pm

Re: Misalignment of meshes

Postby luisg » Mon Sep 08, 2014 11:57 am

Misalignments:
Attachments
2014-09-04_14-45-56.jpg
2014-09-05_07-53-46.jpg
2014-09-05_09-12-02.jpg
www.digitalizacion-3d.com
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Posts: 17
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Re: Misalignment of meshes

Postby luisg » Mon Sep 08, 2014 11:59 am

Errors:
Attachments
2014-09-05_07-53-21.jpg
Gap
2014-09-05_11-44-16.jpg
Gap
2014-09-05_10-32-01.jpg
Noise
www.digitalizacion-3d.com
luisg
 
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Re: Misalignment of meshes

Postby luisg » Mon Sep 08, 2014 12:00 pm

Noise and gaps details:
Attachments
2014-09-05_15-12-41.jpg
2014-09-05_15-13-26.jpg
www.digitalizacion-3d.com
luisg
 
Posts: 17
Joined: Fri Aug 08, 2014 8:33 pm

Re: Misalignment of meshes

Postby hunkatibor2 » Mon Sep 08, 2014 3:33 pm

Hi
Impressive figures, all credit to the artist.Computer data you want.
Tibor
Intel Xeon E5410 2.33GHZ 16GB RAM Windows 7 64bit David 4.5.0
2 Basler A622F camera 2 Tamron Asfirical AF 28-80mm lense
LG DLP Projector PF1500G Canon D40 Tokina 17-70mm 1:2.8-4,5
Humanti Calibration panel system and Alignmed&Two camera
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Re: Misalignment of meshes

Postby NARMELLA » Mon Sep 08, 2014 4:47 pm

Congratulations
Nice scans :)

About errors :

You can find many useful ideas in this forum, But in addition ;
Some tips and tricks to get best scanning and aligning results :

- Each lens has its own focusable area . make sure your camera and projector are focused to the scanning area and live view is sharp and not blurred ; If not change the tripod position .
- Depending to the geometry of scanning part , you can use vertical setup "cam above the projector" or horizontal setup " cam positioned next to the projector "or use a combination of both "Not at a time ", to See more visible projected lines by camera .

- Decide that which type of alignment do you want to use ?
in this case :
1-contact pair selection : it would be good to use some geometrical shapes like spheres around or on the scanning part to get precise alignment.
2-use texture : I prefer to use this one ; it's really quick and precise
Take a look here .

- Gunter has introduced A good way to aligning complex scans take a look here and here

NARMELLA
Data projector : NEC VE 281
Camera(s) : Canon eos 600D (3x)
Software : Lets scan 2.5 + David laser scanner 3.9
گشتاور صنعت تبریز
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Re: Misalignment of meshes

Postby JDM Dyno » Mon Sep 08, 2014 10:45 pm

looks really good!!
the gaps look like you had shadowed areas, you could scan from a different angle
or put the camera on the other side of the projector and re scan the gap parts
Camera's: 2 x DFK 42BUC03 Duel Camera,
c615 modified with Computar megapixel lens
lenses: 2 x Pentax 12mm, 2 x Computar 8mm
Optoma ML300 Projector
Turntable

www.jdm-dyno.co.uk
User avatar
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Posts: 185
Joined: Sat May 10, 2014 9:32 pm
Location: England

Re: Misalignment of meshes

Postby luisg » Tue Sep 09, 2014 6:24 pm

Hi,

Thak you Narmella, Tibor and JDM Dyno, for your help and advice, I will read the post that says Narmela. Tomorrow if I can I will try with another relief, this time smaller and will capture the texture. I will try to scan at higher resolution.

This I have scanned with contact pair selection.

I try to change the position of the camera and projector and if I can, a vertical setup.

Thank you !!!
www.digitalizacion-3d.com
luisg
 
Posts: 17
Joined: Fri Aug 08, 2014 8:33 pm


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