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Author Topic: OBJ File Standard  (Read 8530 times)

James

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OBJ File Standard
« on: May 02, 2012, 07:19:43 PM »
OBJ files exported from Photoscan do not import into 3D Reshaper (http://www.3dreshaper.com/).

I contacted Technodigit to see if this was a bug with their software, with an example OBJ, but they state that the OBJ is not compliant and should contain the following lines:

Code: [Select]
...
vt 0.454957 0.497448
vt 0.507275 0.474474

---------Code to add------------
g Mesh1
usemtl Textured
------- End code to add------------

f 1/10 2/11 3/12
f 1/10 8/17 6/15
f 1/10 6/15 5/14
...
http://www.technodigit.com/forum/viewtopic.php?f=6&t=20

Is this a shortcoming of Photoscan, or is the OBJ standard just not well defined?

James

Alexey Pasumansky

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Re: OBJ File Standard
« Reply #1 on: May 02, 2012, 07:50:38 PM »
Hello James,

In the sample .obj file you've provided there is no "usemtl Textured" line in the start of file, but in the latest releases PhotoScan adds this line into exported file.
Could you please check if adding the line allows the model to be imported to 3D Reshaper or "g Mesh1" line is also required.

Also we recommend to use the latest release.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Wishgranter

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Re: OBJ File Standard
« Reply #2 on: May 02, 2012, 11:02:40 PM »
Alexey i get this sort of problem today, when exported from latest PRO beta version im cannot import in Geomagic studio the OBJ file. i get just error regarding memory but that point in some problem in OBJ file. Few moments back im opened in the Standard version exported OBJ and it can be opened in Geomagic..

But my files have over 1 GB in size.... cannot upload.....
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Wishgranter

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Re: OBJ File Standard
« Reply #3 on: May 03, 2012, 12:22:28 AM »
Afther updating to 1423 version it can be opened in Geomagic.....

Still interesant that dferent versions make different file size of OBJ......
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James

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Re: OBJ File Standard
« Reply #4 on: May 03, 2012, 12:13:00 PM »
I am using 1423.

To import to 3D Reshaper I needed to add both lines to import the mesh at all.

To import to Meshlab I didn't need to add any lines and the mesh was correctly textured.

To import to Blender I needed to add the usemtl line for the texure to be applied on import.

Once imported to 3D Reshaper, the UV mapping appeared incorrect, but since it is fine in photoscan, blender and meshlab it is probably their problem?

Wishgranter

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Re: OBJ File Standard
« Reply #5 on: May 03, 2012, 07:13:07 PM »
Hmm, tested in The Reshaper - today get trial

cannot import files, must resave in Geomagic for that.... and the resulting file get from 105 MB to 85 MB size......
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James

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Re: OBJ File Standard
« Reply #6 on: May 04, 2012, 12:53:37 PM »
Sorry just rechecked, and didn't need to add anything to import to blender with texture/material already attached.

3dreshaper is very powerful, great for pointcloud to mesh, but still has a lot of bugs. I haven't tried geomagic, i think it's probably better but possibly beyond our budget at the moment.