[Insight-developers] Simplex Volume Calculator

[Luis Ibanez]

Jim,

Thanks for looking into this issue.

Yes, the problem could also be in
the TriangleMeshToSimplexMeshFilter.. or...
it still could be an actual bug in the Calculator.

I guess that the right test to perform is the
one you suggest: converting the meshes to VTK
and checking their normals.

The application

   InsightApplications/DeformableModelSimplexMesh

maybe a good place for performing such test.


    Luis



---------------------------------
Miller, James V (Research) wrote:

> I just took a quick look at the RegularSphere code.  I don't see 
> anything that would suggest an inproper ordering. 'Course the best
> way to tell would be to write out a VTK file and see if the normals
> are flipped. Haven't tried that yet.
> 
> Could the problem be in the TriangleMeshToSimplexMeshFilter? This
> filter takes the nice triangle mesh and converts into some other
> structure based on the center points of the triangles. I guess I don't
> understand what a SimplexMesh is.
> 
> TriangleMeshToSimplexMeshFilter claims to reorient the vertices for
> geometry computations.  Since it looks like the triangles may have
> been oriented correctly, maybe the "reorientation" code in incorrect.
> 
> The RegularSphere could still be incorrect. I just made a quick 
> pass through the logic and drew a few pictures that made it seem
> like it was doing the right thing.
> 
> Jim
> 
> 
> 
> -----Original Message-----
> From: Luis Ibanez [mailto:luis.ibanez at kitware.com]
> Sent: Monday, November 01, 2004 9:01 AM
> To: Lorensen, William E (Research)
> Cc: insight-developers at public.kitware.com
> Subject: Re: [Insight-developers] Simplex Volume Calculator
> 
> 
> 
> Bill,
> 
> Yes, the reason is that the class is expecting the input surface
> to be oriented and unfortunately it seems that the RegularSphere
> surface class is not generating a triangulation with neighbor
> links oriented consistently (clockwise or counter clockwise).
> 
> That can be considered to be a bug in the SphereSimplexMeshSource... 
> or... maybe what we need a filter that will take a Mesh and reorder
> the neighbor links in order to orient it.
> 
> 
>    Luis
> 
> 
> ----------------------------------------
> Lorensen, William E (Research) wrote:
> 
> 
>>Luis,
>>The test of the new class is failing on all platforms.
>>
>>Bill
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>>
>>
> 
> 
> 
> 
> 
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