text: #!/usr/bin/env python
  
  import vtk
  from vtk.util.misc import vtkGetDataRoot
  
  # create planes
  # Create the RenderWindow, Renderer
  #
  ren = vtk.vtkRenderer()
  renWin = vtk.vtkRenderWindow()
  renWin.AddRenderer( ren )
  
  iren = vtk.vtkRenderWindowInteractor()
  iren.SetRenderWindow(renWin)
  
  # create pipeline
  #
  pl3d = vtk.vtkMultiBlockPLOT3DReader()
  pl3d.SetXYZFileName( vtkGetDataRoot() + '/Data/combxyz.bin' )
  pl3d.SetQFileName( vtkGetDataRoot() + '/Data/combq.bin' )
  pl3d.SetScalarFunctionNumber( 100 )
  pl3d.SetVectorFunctionNumber( 202 )
  pl3d.Update()
  pl3d_output = pl3d.GetOutput().GetBlock(0)
  
  outline = vtk.vtkStructuredGridOutlineFilter()
  outline.SetInputData(pl3d_output)
  
  outlineMapper = vtk.vtkPolyDataMapper()
  outlineMapper.SetInputConnection(outline.GetOutputPort())
  
  outlineActor = vtk.vtkActor()
  outlineActor.SetMapper(outlineMapper)
  
  seeds = vtk.vtkLineSource()
  seeds.SetPoint1(15, -5, 32)
  seeds.SetPoint2(15, 5, 32)
  seeds.SetResolution(10)
  
  sl = vtk.vtkStreamTracer()
  sl.SetInputData(pl3d_output)
  sl.SetSourceConnection(seeds.GetOutputPort())
  sl.SetMaximumPropagation(100)
  sl.SetInitialIntegrationStep(0.1)
  sl.SetIntegrationDirectionToBoth()
  
  mapper = vtk.vtkPolyDataMapper()
  mapper.SetInputConnection(sl.GetOutputPort())
  
  actor = vtk.vtkActor()
  actor.SetMapper(mapper)
  
  mmapper = vtk.vtkPolyDataMapper()
  mmapper.SetInputConnection(seeds.GetOutputPort())
  mactor = vtk.vtkActor()
  mactor.SetMapper(mmapper)
  ren.AddActor(mactor)
  
  ren.AddActor(actor)
  ren.AddActor(outlineActor)
  
  cam=ren.GetActiveCamera()
  cam.SetClippingRange( 3.95297, 50 )
  cam.SetFocalPoint( 8.88908, 0.595038, 29.3342 )
  cam.SetPosition( -12.3332, 31.7479, 41.2387 )
  cam.SetViewUp( 0.060772, -0.319905, 0.945498 )
  
  renWin.Render()
  