title: How to draw primitives (points, lines etc) in vtk?
body: <p>I need to draw primitives on a vtkActor, but I don't know how. Maybe I may use opengl functions for this? In this example <a href="http://www.vtk.org/Wiki/VTK/Examples/Cxx/Plotting/Diagram" rel="nofollow noreferrer">http://www.vtk.org/Wiki/VTK/Examples/Cxx/Plotting/Diagram</a> it's working, but I need to draw it interactively. 
  Thanks for answers.</p>