new_contents: import vtk
  
  def setup(): 
      # create a rendering window and renderer
      ren = vtk.vtkRenderer()
      renWin = vtk.vtkRenderWindow()
      renWin.AddRenderer(ren)
       
      # create a renderwindowinteractor
      iren = vtk.vtkRenderWindowInteractor()
      iren.SetRenderWindow(renWin)
      return ren,renWin,iren
  
  def create_sphere(ren=None,r=5.0,center=(0,0,0)):
      if ren is None:
          ren,renWin,iren=setup()
      
      # create source
      source = vtk.vtkSphereSource()
      source.SetCenter(0,0,0)
      source.SetRadius(5.0)
   
      # mapper
      mapper = vtk.vtkPolyDataMapper()
      mapper.SetInput(source.GetOutput())
   
      # actor
      actor = vtk.vtkActor()
      actor.SetMapper(mapper)
   
      # assign actor to the renderer
      ren.AddActor(actor)
      return source
       
  
subject: Add simple VTK example (to be put inside an event driver)