[vtkusers] problem with vtkGridTransform

[Pallavi Joshi]

  Hi All,
  I have a C array pointer with 3 displacement fields dx,dy,dz for each voxel of my image volume. I import this pointer using vtkImageImport by using the following piece of code:
  vtkImageImport *importer = vtkImageImport::New();
   importer->SetWholeExtent(0,255,0,255,0,255);
   importer->SetDataExtentToWholeExtent();
   importer->SetDataScalarTypeToUnsignedShort();
   importer->SetDataSpacing(1,1,1);
   importer->SetImportVoidPointer(dr);

  where, 'dr' is my array pointer. The dimensions of my image volume are 256x256x256 with voxel dimensions of 1mmx1mmx1mm. Hence I have created a vtkImageData with the extent of 0,255,0,255,0,255 as done above. Does this mean that I create a grid of dimensions 256x256x256 and spacing of 1x1x1 and each grid element will carry my 3 displacement vector values dx,dy,dz. ? I am using the following piece of code for transformation:

  vtkGridTransform *nrtransf = vtkGridTransform::New();
   nrtransf->SetDisplacementGrid(importer->GetOutput());
   nrtransf->SetInterpolationModeToCubic();

   vtkPolyDataReader *reader = vtkPolyDataReader::New();
   reader->SetFileName("//isotropic/brainstem.vtk");
   
   vtkTransformPolyDataFilter *def = vtkTransformPolyDataFilter::New();
   def->SetInput( reader->GetOutput() );
   def->SetTransform( nrtransf );
  Is this code correct ? I am getting some error in vtkGridTransform. I am not able to figure out how to fix it. 
  Could anyone please help me and guide me in the right direction ?

  Thank You very much,
  Pallavi

    




   

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