[vtk-developers] [VTK 0013827]: Incorrect contouring on quadratic tetrahedrons.

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://www.vtk.org/Bug/view.php?id=13827 
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Reported By:                Mark Van Moer
Assigned To:                
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Project:                    VTK
Issue ID:                   13827
Category:                   (No Category)
Reproducibility:            have not tried
Severity:                   minor
Priority:                   high
Status:                     backlog
Project:                    TBD 
Type:                       incorrect functionality 
Resolution:                 open
Fixed in Version:           
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Date Submitted:             2013-01-28 16:24 EST
Last Modified:              2013-01-28 16:24 EST
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Summary:                    Incorrect contouring on quadratic tetrahedrons.
Description: 
When a VTK_QUADRATIC_TETRA is contoured, visual artifacts can appear depending
on the orientation of the data relative to the internal decomposition. A
quadratic tetra is decomposed inside of vtkQuadraticTetra.cxx into 8 linear
tetras: 4 for the corners and 4 that make a central octahedron. The 4 central
linear tetras share a diagonal of the octahedron. Values interpolated along this
diagonal get interpolated as if the linear tetra was independent of the
quadratic tetra.

Data that is the central tetra region perpendicular to the diagonal is
interpolated correctly.

Attached is a tarball with 2 small test unstructured grid data sets, images from
those sets, and an image showing the effect in a fluid simulation.
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Issue History 
Date Modified    Username       Field                    Change               
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2013-01-28 16:24 Mark Van Moer  New Issue                                    
2013-01-28 16:24 Mark Van Moer  File Added: contouringQuadTets.tar.gz           
        
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