[MINC-users] Details about cortical surface object file

[Jason Lerch]

It's also quite easy to use the bicpl C functions to read an obj file. 
Take a look at the bicInventor library for one example. Lastly we also 
have a number of converters - so if you can already read an inventor or 
VTK format file, for example, you can just convert the obj file to that 
format.

Jason

Simon Fristed Eskildsen wrote:
> Hi Ed,
> The layout of an .obj (MNI style) file is:
>
> Vertex header (Ex. "P 1.0 1.0 1.0 100 1 180098")
> Vertex coordinates
> Vertex normals
> Polygon header (Ex. "359544 2")
> Vertex/triangle colours
> Polygon indices (defines the start of each polygon in the vertex 
> indices below)
> Vertex indices (defines each polygon)
>
> Here is a simple cube in triangle polygon format with red and blue 
> vertex coloring:
>
> P 0.3 0.3 0.4 10 1 8
> 0 0 0
> 0 0 100
> 0 100 0
> 0 100 100
> 100 0 0
> 100 0 100
> 100 100 0
> 100 100 100
>
> -0.666667 -0.333333 -0.666667
> -0.333333 -0.666667 0.666667
> -0.408248 0.816497 -0.408248
> -0.816497 0.408248 0.408248
> 0.408248 -0.816497 -0.408248
> 0.816497 -0.408248 0.408248
> 0.666667 0.333333 -0.666667
> 0.333333 0.666667 0.666667
>
> 12 2
> 0.0 0.0 1.0 1
> 0.0 0.0 1.0 1
> 0.0 0.0 1.0 1
> 0.0 0.0 1.0 1
> 1.0 0.0 0.0 1
> 1.0 0.0 0.0 1
> 1.0 0.0 0.0 1
> 1.0 0.0 0.0 1
>
> 3 6 9 12 15 18 21 24 27 30 33 36
>
> 0 1 3 0 3 2 2 3 7 2 7 6 6 7 5 6 5 4 4 5 1 4 1 0 1 5 7 1 7 3 0 2 6 0 6 4
>
> See also http://wiki.bic.mni.mcgill.ca/index.php/ObjectFiles
> The description there lacks the color information though.
>
> Simon
>
> Ed Gronenschild wrote:
>> Hi,
>>
>> I would like to import the output file (extension .obj) of  
>> cortical_surface
>> into a private Mac OS X application. Is there a description of this file
>> and how to read and use it. Of course, I could go through the source
>> files of Display, but that would take me a lot of time.
>>
>> Regards,
>> Ed
>> _______________________________________________
>> MINC-users at bic.mni.mcgill.ca
>> http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users
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>
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