#!/usr/bin/env python

# create points in the configuration of an octant with one 2:1 face
#
points = vtk.vtkPoints()
aConvex = vtk.vtkConvexPointSet()
points.InsertPoint(0,0,0,0)
points.InsertPoint(1,1,0,0)
points.InsertPoint(2,1,1,0)
points.InsertPoint(3,0,1,0)
points.InsertPoint(4,0,0,1)
points.InsertPoint(5,1,0,1)
points.InsertPoint(6,1,1,1)
points.InsertPoint(7,0,1,1)
points.InsertPoint(8,0.5,0,0)
points.InsertPoint(9,1,0.5,0)
points.InsertPoint(10,0.5,1,0)
points.InsertPoint(11,0,0.5,0)
points.InsertPoint(12,0.5,0.5,0)
i = 0
while i < 13:
    aConvex.GetPointIds().InsertId(i,i)
    i = i + 1

aConvexGrid = vtk.vtkUnstructuredGrid()
aConvexGrid.Allocate(1,1)
aConvexGrid.InsertNextCell(aConvex.GetCellType(),aConvex.GetPointIds())
aConvexGrid.SetPoints(points)
# Display the cell
dsm = vtk.vtkDataSetMapper()
dsm.SetInputData(aConvexGrid)
a = vtk.vtkActor()
a.SetMapper(dsm)
a.GetProperty().SetColor(0,1,0)
# Contour and clip the cell with elevation scalars
ele = vtk.vtkElevationFilter()
ele.SetInputData(aConvexGrid)
ele.SetLowPoint(-1,-1,-1)
ele.SetHighPoint(1,1,1)
ele.SetScalarRange(-1,1)
# Clip
#
clip = vtk.vtkClipDataSet()
clip.SetInputConnection(ele.GetOutputPort())
clip.SetValue(0.5)
g = vtk.vtkDataSetSurfaceFilter()
g.SetInputConnection(clip.GetOutputPort())
map = vtk.vtkPolyDataMapper()
map.SetInputConnection(g.GetOutputPort())
map.ScalarVisibilityOff()
clipActor = vtk.vtkActor()
clipActor.SetMapper(map)
clipActor.GetProperty().SetColor(1,0,0)
clipActor.AddPosition(2,0,0)
# Contour
#
contour = vtk.vtkContourFilter()
contour.SetInputConnection(ele.GetOutputPort())
contour.SetValue(0,0.5)
g2 = vtk.vtkDataSetSurfaceFilter()
g2.SetInputConnection(contour.GetOutputPort())
map2 = vtk.vtkPolyDataMapper()
map2.SetInputConnection(g2.GetOutputPort())
map2.ScalarVisibilityOff()
contourActor = vtk.vtkActor()
contourActor.SetMapper(map2)
contourActor.GetProperty().SetColor(1,0,0)
contourActor.AddPosition(1,2,0)
# Create graphics stuff
#
ren1 = vtk.vtkRenderer()
renWin = vtk.vtkRenderWindow()
renWin.AddRenderer(ren1)
iren = vtk.vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)
# Add the actors to the renderer, set the background and size
#
ren1.AddActor(a)
ren1.AddActor(clipActor)
ren1.AddActor(contourActor)
ren1.SetBackground(1,1,1)
renWin.SetSize(250,150)
aCam = vtk.vtkCamera()
aCam.SetFocalPoint(1.38705,1.37031,0.639901)
aCam.SetPosition(1.89458,-5.07106,-4.17439)
aCam.SetViewUp(0.00355726,0.598843,-0.800858)
aCam.SetClippingRange(4.82121,12.1805)
ren1.SetActiveCamera(aCam)
renWin.Render()
cam1 = ren1.GetActiveCamera()
cam1.Zoom(1.5)
# render the image
#
renWin.Render()
# prevent the tk window from showing up then start the event loop
# --- end of script --
