[vtk-developers] [VTK 0013455]: vtkCellDerivatives computes wrong results on quadratic quadrilateral cells

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://www.vtk.org/Bug/view.php?id=13455 
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Reported By:                Simon Triebenbacher
Assigned To:                
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Project:                    VTK
Issue ID:                   13455
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:             2012-09-14 04:57 EDT
Last Modified:              2012-09-14 04:57 EDT
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Summary:                    vtkCellDerivatives computes wrong results on
quadratic quadrilateral cells
Description: 
When trying to calculate the fluid strain rates on second order quadrilateral
elements the PV 3.14.1 ComputeDerivatives filter produced the wrong results. I
was able to reproduce the bug with a simple ramp function in y-direction in PV
3.14.1 and PV 3.10.1, c.f. y-Ramp_and_ScalarGradient_X.png and
y-Ramp_and_ScalarGradient_X.pvsm in attached zip file.

I attached a patch, which fixes the mentioned bug. I did not take care about
efficency concerns, however.

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Issue History 
Date Modified    Username       Field                    Change               
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2012-09-14 04:57 Simon TriebenbacherNew Issue                                   

2012-09-14 04:57 Simon TriebenbacherFile Added: vtkpatch_quadratic_quads.zip    
               
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