#!/usr/bin/env python
import vtk
from vtk.util.misc import vtkGetDataRoot
VTK_DATA_ROOT = vtkGetDataRoot()

# read in a Chaco file
chReader = vtk.vtkChacoReader()
chReader.SetBaseName(VTK_DATA_ROOT + "/Data/vwgt")
chReader.SetGenerateGlobalElementIdArray(1)
chReader.SetGenerateGlobalNodeIdArray(1)
chReader.SetGenerateEdgeWeightArrays(1)
chReader.SetGenerateVertexWeightArrays(1)

geom = vtk.vtkGeometryFilter()
geom.SetInputConnection(chReader.GetOutputPort())

mapper = vtk.vtkPolyDataMapper()
mapper.SetInputConnection(geom.GetOutputPort())
mapper.SetColorModeToMapScalars()
mapper.SetScalarModeToUsePointFieldData()
mapper.SelectColorArray("VertexWeight1")
mapper.SetScalarRange(1, 5)

actor0 = vtk.vtkActor()
actor0.SetMapper(mapper)

# Create the RenderWindow, Renderer and interactor
#
ren1 = vtk.vtkRenderer()
renWin = vtk.vtkRenderWindow()
renWin.AddRenderer(ren1)
iren = vtk.vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)

# Add the actor to the renderer, set the background and size
#
ren1.AddActor(actor0)
ren1.SetBackground(0, 0, 0)

renWin.SetSize(300, 300)
renWin.SetMultiSamples(0)

iren.Initialize()

renWin.Render()

#iren.Start()