VTK/Examples/Cxx/PolyData/WeightedTransformFilter

#include <vtkVersion.h>
#include <vtkSphereSource.h>
#include <vtkTransformFilter.h>
#include <vtkProperty.h>
#include <vtkCamera.h>
#include <vtkFloatArray.h>
#include <vtkPointData.h>
#include <vtkPolyData.h>
#include <vtkSmartPointer.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkTransform.h>
#include <vtkWeightedTransformFilter.h>
 
int main(int argc, char *argv[])
{
  // Use a sphere as a basis of the shape
  vtkSmartPointer<vtkSphereSource> sphere =
    vtkSmartPointer<vtkSphereSource>::New();
  sphere->SetPhiResolution(40);
  sphere->SetThetaResolution(40);
  sphere->Update();
 
  vtkPolyData* sphereData = sphere->GetOutput();
 
  // Create a data array to hold the weighting coefficients
  vtkSmartPointer<vtkFloatArray> tfarray =
    vtkSmartPointer<vtkFloatArray>::New();
  vtkIdType npoints = sphereData->GetNumberOfPoints();
  tfarray->SetNumberOfComponents(2);
  tfarray->SetNumberOfTuples(npoints);
 
  // Parameterize the sphere along the z axis, and fill the weights
  // with (1.0-a, a) to linearly interpolate across the shape
  for(int i = 0; i < npoints; i++)
    {
    double pt[3];
    sphereData->GetPoint(i, pt);
    double x = pt[0];
    double y = pt[1];
    double z = pt[2];
 
    double zn = z + 0.5;
    double zn1 = 1.0 - zn;
    if(zn > 1.0)
      {
      zn = 1.0;
      }
    if(zn1 < 0.0)
      {
      zn1 = 0.0;
      }
 
    tfarray->SetComponent(i, 0, zn1);
    tfarray->SetComponent(i, 1, zn);
  }
 
  // Create field data to hold the array, and bind it to the sphere
  vtkSmartPointer<vtkFieldData> fd =
    vtkSmartPointer<vtkFieldData>::New();
  tfarray->SetName("weights");
  sphereData->GetPointData()->AddArray(tfarray);
 
  // Use an ordinary transform to stretch the shape
  vtkSmartPointer<vtkTransform> stretch =
    vtkSmartPointer<vtkTransform>::New();
  stretch->Scale(1, 1, 3.2);
 
  vtkSmartPointer<vtkTransformFilter> stretchFilter =
    vtkSmartPointer<vtkTransformFilter>::New();
#if VTK_MAJOR_VERSION <= 5
  stretchFilter->SetInput(sphereData);
#else
  stretchFilter->SetInputData(sphereData);
#endif
  stretchFilter->SetTransform(stretch);
 
  // Now, for the weighted transform stuff
  vtkSmartPointer<vtkWeightedTransformFilter> weightedTrans =
    vtkSmartPointer<vtkWeightedTransformFilter>::New();
 
  // Create two transforms to interpolate between
  vtkSmartPointer<vtkTransform> identity =
    vtkSmartPointer<vtkTransform>::New();
  identity->Identity();
 
  vtkSmartPointer<vtkTransform> rotated =
    vtkSmartPointer<vtkTransform>::New();
  double rotatedAngle = 45;
  rotated->RotateX(rotatedAngle);
 
  weightedTrans->SetNumberOfTransforms(2);
  weightedTrans->SetTransform(identity, 0);
  weightedTrans->SetTransform(rotated, 1);
  // which data array should the filter use ?
  weightedTrans->SetWeightArray("weights");
 
  weightedTrans->SetInputConnection(stretchFilter->GetOutputPort());
 
  vtkSmartPointer<vtkPolyDataMapper> weightedTransMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  weightedTransMapper->SetInputConnection(weightedTrans->GetOutputPort());
  vtkSmartPointer<vtkActor> weightedTransActor =
    vtkSmartPointer<vtkActor>::New();
  weightedTransActor->SetMapper(weightedTransMapper);
  weightedTransActor->GetProperty()->SetDiffuseColor(0.8, 0.8, 0.1);
  weightedTransActor->GetProperty()->SetRepresentationToSurface();
 
  // Visualize
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> interactor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);
 
  renderer->AddActor(weightedTransActor);
  renderer->SetBackground(0.1, 0.2, 0.5);
  renderWindow->SetSize(300, 300);
 
  renderer->ResetCamera();
  renderer->GetActiveCamera()->Azimuth(90);
  renderer->GetActiveCamera()->Dolly(1);
 
  renderWindow->Render();
 
  interactor->Start();
 
  return EXIT_SUCCESS;
}