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

# Example demonstrates how to generate a 3D tetrahedra mesh from a volume
#
# Quadric definition
quadric = vtk.vtkQuadric()
quadric.SetCoefficients([.5,1,.2,0,.1,0,0,.2,0,0])
sample = vtk.vtkSampleFunction()
sample.SetSampleDimensions(20,20,20)
sample.SetImplicitFunction(quadric)
sample.ComputeNormalsOff()
# Generate tetrahedral mesh
clip = vtk.vtkClipVolume()
clip.SetInputConnection(sample.GetOutputPort())
clip.SetValue(1.0)
clip.GenerateClippedOutputOff()
clipMapper = vtk.vtkDataSetMapper()
clipMapper.SetInputConnection(clip.GetOutputPort())
clipMapper.ScalarVisibilityOff()
clipActor = vtk.vtkActor()
clipActor.SetMapper(clipMapper)
clipActor.GetProperty().SetColor(.8,.4,.4)
# Create outline
outline = vtk.vtkOutlineFilter()
#  outline SetInputData [clip GetInput]
outline.SetInputConnection(sample.GetOutputPort())
outlineMapper = vtk.vtkPolyDataMapper()
outlineMapper.SetInputConnection(outline.GetOutputPort())
outlineActor = vtk.vtkActor()
outlineActor.SetMapper(outlineMapper)
outlineActor.GetProperty().SetColor(0,0,0)
# Define graphics objects
ren1 = vtk.vtkRenderer()
renWin = vtk.vtkRenderWindow()
renWin.SetMultiSamples(0)
renWin.AddRenderer(ren1)
iren = vtk.vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)
ren1.SetBackground(1,1,1)
ren1.AddActor(clipActor)
ren1.AddActor(outlineActor)
iren.Initialize()
# --- end of script --
