private void WeightedTransformFilter()
{
// Use a sphere as a basis of the shape
vtkSphereSource sphere = vtkSphereSource.New();
sphere.SetPhiResolution(40);
sphere.SetThetaResolution(40);
sphere.Update();
vtkPolyData sphereData = sphere.GetOutput();
// Create a data array to hold the weighting coefficients
vtkFloatArray tfarray = vtkFloatArray.New();
int 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
IntPtr pPoint = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(double)) * 3);
double[] point = new double[3];
for (int i = 0; i < npoints; i++)
{
sphereData.GetPoint(i, pPoint);
Marshal.Copy(pPoint, point, 0, 3);
double x = point[0];
double y = point[1];
double z = point[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);
}
Marshal.FreeHGlobal(pPoint);
// Create field data to hold the array, and bind it to the sphere
vtkFieldData fd = vtkFieldData.New();
tfarray.SetName("weights");
sphereData.GetPointData().AddArray(tfarray);
// Use an ordinary transform to stretch the shape
vtkTransform stretch = vtkTransform.New();
stretch.Scale(1, 1, 3.2);
vtkTransformFilter stretchFilter = vtkTransformFilter.New();
stretchFilter.SetInputConnection(sphereData.GetProducerPort());
stretchFilter.SetTransform(stretch);
// Now, for the weighted transform stuff
vtkWeightedTransformFilter weightedTrans = vtkWeightedTransformFilter.New();
// Create two transforms to interpolate between
vtkTransform identity = vtkTransform.New();
identity.Identity();
vtkTransform rotated = 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());
vtkPolyDataMapper weightedTransMapper = vtkPolyDataMapper.New();
weightedTransMapper.SetInputConnection(weightedTrans.GetOutputPort());
vtkActor weightedTransActor = vtkActor.New();
weightedTransActor.SetMapper(weightedTransMapper);
weightedTransActor.GetProperty().SetDiffuseColor(0.8, 0.8, 0.1);
weightedTransActor.GetProperty().SetRepresentationToSurface();
// get a reference to the renderwindow of our renderWindowControl1
vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
// renderer
vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
// set background color
renderer.SetBackground(0.2, 0.3, 0.4);
// add our actor to the renderer
renderer.AddActor(weightedTransActor);
renderer.ResetCamera();
renderer.GetActiveCamera().Azimuth(90);
renderer.GetActiveCamera().Dolly(1);
}