Hello,<br>I have the unstructured grid image printed at end of this email, with two point data sets "Dispamcement" (vectors) and
"Optimizer Value" (scalors). I want to use vtkCellDerivatives to
calculate the strain tensors from the "Displacement" point data. I can't
figure out how to input the data into vtkCellDerivatives. I have tried:<br><br>vtkCellDerivatives *dCalc = vtkCellDerivatives::New();<br>dCalc->SetTensorModeToComputeStrain();<br>dCalc->SetInput( image->GetPointData()->GetArray("Displacement") );<br>
dCalc->Update();<br><br>and<br><br>vtkCellDerivatives *dCalc = vtkCellDerivatives::New();<br>
dCalc->SetTensorModeToComputeStrain();<br>dCalc->SetInput(image);<br>dCalc->SetInputArrayToProcess( [uh...I get lost here, I've tried a lot of things]Â );<br>dCalc->Update();<br><br>I either can't get it to compile, or the output of the filter is the same as the input.<br>
<br>Can anybody point me in the right direction?<br><br>Thanks,<br>Seth<br><br>The cells in the image are quadratic tets.<br><br>image->Print( std::cout )...<br><br>vtkUnstructuredGrid (0x10f1150)<br>Â Debug: Off<br>Â Modified Time: 268<br>
 Reference Count: 1<br> Registered Events: (none)<br> Source: (none)<br> Information: 0x10e6130<br> Data Released: False<br> Global Release Data: Off<br> UpdateTime: 269<br> Release Data: Off<br> UpdateExtent: Not Initialized<br>
 Update Number Of Pieces: 1<br> Update Piece: 0<br> Update Ghost Level: 0<br> MaximumNumberOfPieces: 1<br> RequestExactExtent: Off<br>  Field Data:<br>   Debug: Off<br>   Modified Time: 252<br>   Reference Count: 1<br>
   Registered Events: (none)<br>   Number Of Arrays: 0<br>   Number Of Components: 0<br>   Number Of Tuples: 0<br> Number Of Points: 81<br> Number Of Cells: 30<br> Cell Data:<br>   Debug: Off<br>   Modified Time: 259<br>
   Reference Count: 1<br>   Registered Events: (none)<br>   Number Of Arrays: 0<br>   Number Of Components: 0<br>   Number Of Tuples: 0<br>   Copy Tuple Flags: ( 1 1 1 1 1 0 1 )<br>   Interpolate Flags: ( 1 1 1 1 1 0 0 )<br>
   Pass Through Flags: ( 1 1 1 1 1 1 1 )<br>   Scalars: (none)<br>   Vectors: (none)<br>   Normals: (none)<br>   TCoords: (none)<br>   Tensors: (none)<br>   GlobalIds: (none)<br>   PedigreeIds: (none)<br> Point Data:<br>
   Debug: Off<br>   Modified Time: 268<br>   Reference Count: 1<br>   Registered Events: (none)<br>   Number Of Arrays: 2<br>   Array 0 name = Displacement<br>   Array 1 name = Optimizer Value<br>   Number Of Components: 4<br>
   Number Of Tuples: 81<br>   Copy Tuple Flags: ( 1 1 1 1 1 0 1 )<br>   Interpolate Flags: ( 1 1 1 1 1 0 0 )<br>   Pass Through Flags: ( 1 1 1 1 1 1 1 )<br>   Scalars: (none)<br>   Vectors: (none)<br>   Normals: (none)<br>
   TCoords: (none)<br>   Tensors: (none)<br>   GlobalIds: (none)<br>   PedigreeIds: (none)<br> Bounds: <br>   Xmin,Xmax: (57.5, 67.3)<br>   Ymin,Ymax: (45.7, 56.7)<br>   Zmin,Zmax: (41.7, 59.1)<br> Compute Time: 283<br>
 Number Of Points: 81<br> Point Coordinates: 0x10e7890<br> Locator: 0<br> Number Of Pieces: 1<br> Piece: 0<br> Ghost Level: 0<span style="font-family: courier new,monospace;"><br></span><br><br><br>