Paraview Programmable Filter example

ProgrammableFilter

# Get a vtk.PolyData object for the input
pdi = self.GetPolyDataInput()
# Get a vtk.PolyData object for the output
pdo = self.GetPolyDataOutput()

numPoints = pdi.GetNumberOfPoints()

# Points for the line:
newPoints = vtk.vtkPoints()
for i in range(0, numPoints):
    # Generate the new points from the input
    coord = pdi.GetPoint(i)
    x, y, z = coord[:3]
    newPoints.InsertPoint(i, x, y, z)

# Add the new points to the PolyData object:
pdo.SetPoints(newPoints)

# Make a line from the new points:
aPolyLine = vtk.vtkPolyLine()

#Indicate the number of points along the line
aPolyLine.GetPointIds().SetNumberOfIds(numPoints)
for i in range(0,numPoints):
   #Add the points to the line. The first value indicates
   #the order of the point on the line. The second value
   #is a reference to a point in a vtkPoints object. Depends
   #on the order that Points were added to vtkPoints object.
   #Note that this will not be associated with actual points
   #until it is added to a vtkPolyData object which holds a
   #vtkPoints object.
   aPolyLine.GetPointIds().SetId(i, i)

#Allocate the number of 'cells' that will be added. We are just
#adding one vtkPolyLine 'cell' to the vtkPolyData object.
pdo.Allocate(1, 1)

#Add the poly line 'cell' to the vtkPolyData object.
pdo.InsertNextCell(aPolyLine.GetCellType(), aPolyLine.GetPointIds())