title: How to display only triangle boundaries on textured surface in vtk?
body: <p>I want to display a surface which is textured. I want the triangles boundaries to be visible over the surface in a different color (lets say red). I have found the following code from the vtk code samples but it does not display the triangle boundaries but the filled triangles.</p>
  
  <pre><code>   import vtk
  
     # create a rendering window and renderer
     ren = vtk.vtkRenderer()
     renWin = vtk.vtkRenderWindow()
     renWin.AddRenderer(ren)
  
     # create a renderwindowinteractor
     iren = vtk.vtkRenderWindowInteractor()
     iren.SetRenderWindow(renWin)
  
     # create points
     points = vtk.vtkPoints()
     points.InsertNextPoint(1.0,0.0,0.0)
     points.InsertNextPoint(0.0,0.0,0.0)
     points.InsertNextPoint(0.0,1.0,0.0)
  
     triangle = vtk.vtkTriangle()
     triangle.GetPointIds().SetId(0,0)
     triangle.GetPointIds().SetId(1,1)
     triangle.GetPointIds().SetId(2,2)
  
     triangles = vtk.vtkCellArray()
     triangles.InsertNextCell(triangle)
  
     # polydata object
     trianglePolyData = vtk.vtkPolyData()
     trianglePolyData.SetPoints( points )
     trianglePolyData.SetPolys( triangles )
  
     # mapper
     mapper = vtk.vtkPolyDataMapper()
     mapper.SetInput(trianglePolyData)
  
     # actor
     actor = vtk.vtkActor()
     actor.SetMapper(mapper)
  
     # assign actor to the renderer
     ren.AddActor(actor)
  
     # enable user interface interactor
     iren.Initialize()
     renWin.Render()
     iren.Start()
  </code></pre>
  
  <p>Can anybody please let me know that how to display triangle only with the boundaries with a specific color. </p>
  
  <p>I ideally i want to display triangles on a textured surface. My data consist of triangles. It might also be possible that the vertices of the triangles which are given to vtk can be made visible.</p>
  
  <p>I am coding in python.</p>
  
  <p>Thanks a lot</p>