# MedicalDemo2

vtk-examples/Python/Medical/MedicalDemo2

### Description¶

Skin and bone isosurfaces.

Usage

Note

This original source code for this example is here.

Info

The example uses src/Testing/Data/FullHead.mhd which references src/Testing/Data/FullHead.raw.gz.

Other languages

See (Cxx), (Java)

Question

### Code¶

MedicalDemo2.py

#!/usr/bin/env python

'''
'''

import vtk

def main():
colors = vtk.vtkNamedColors()

fileName = get_program_parameters()

colors.SetColor('SkinColor', [255, 125, 64, 255])
colors.SetColor('BkgColor', [51, 77, 102, 255])

# Create the renderer, the render window, and the interactor. The renderer
# draws into the render window, the interactor enables mouse- and
# keyboard-based interaction with the data within the render window.
#
aRenderer = vtk.vtkRenderer()
renWin = vtk.vtkRenderWindow()

iren = vtk.vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)

# The following reader is used to read a series of 2D slices (images)
# that compose the volume. The slice dimensions are set, and the
# pixel spacing. The data Endianness must also be specified. The reader
# uses the FilePrefix in combination with the slice number to construct
# filenames using the format FilePrefix.%d. (In this case the FilePrefix
# is the root name of the file: quarter.)

# An isosurface, or contour value of 500 is known to correspond to the
# skin of the patient.
# The triangle stripper is used to create triangle strips from the
# isosurface these render much faster on many systems.
skinExtractor = vtk.vtkMarchingCubes()
skinExtractor.SetValue(0, 500)

skinStripper = vtk.vtkStripper()
skinStripper.SetInputConnection(skinExtractor.GetOutputPort())

skinMapper = vtk.vtkPolyDataMapper()
skinMapper.SetInputConnection(skinStripper.GetOutputPort())
skinMapper.ScalarVisibilityOff()

skin = vtk.vtkActor()
skin.SetMapper(skinMapper)
skin.GetProperty().SetDiffuseColor(colors.GetColor3d('SkinColor'))
skin.GetProperty().SetSpecular(.3)
skin.GetProperty().SetSpecularPower(20)
skin.GetProperty().SetOpacity(.5)

# An isosurface, or contour value of 1150 is known to correspond to the
# bone of the patient.
# The triangle stripper is used to create triangle strips from the
# isosurface these render much faster on may systems.
boneExtractor = vtk.vtkMarchingCubes()
boneExtractor.SetValue(0, 1150)

boneStripper = vtk.vtkStripper()
boneStripper.SetInputConnection(boneExtractor.GetOutputPort())

boneMapper = vtk.vtkPolyDataMapper()
boneMapper.SetInputConnection(boneStripper.GetOutputPort())
boneMapper.ScalarVisibilityOff()

bone = vtk.vtkActor()
bone.SetMapper(boneMapper)
bone.GetProperty().SetDiffuseColor(colors.GetColor3d('Ivory'))

# An outline provides context around the data.
#
outlineData = vtk.vtkOutlineFilter()

mapOutline = vtk.vtkPolyDataMapper()
mapOutline.SetInputConnection(outlineData.GetOutputPort())

outline = vtk.vtkActor()
outline.SetMapper(mapOutline)
outline.GetProperty().SetColor(colors.GetColor3d('Black'))

# It is convenient to create an initial view of the data. The FocalPoint
# and Position form a vector direction. Later on (ResetCamera() method)
# this vector is used to position the camera to look at the data in
# this direction.
aCamera = vtk.vtkCamera()
aCamera.SetViewUp(0, 0, -1)
aCamera.SetPosition(0, -1, 0)
aCamera.SetFocalPoint(0, 0, 0)
aCamera.ComputeViewPlaneNormal()
aCamera.Azimuth(30.0)
aCamera.Elevation(30.0)

# Actors are added to the renderer. An initial camera view is created.
# The Dolly() method moves the camera towards the FocalPoint,
# thereby enlarging the image.
aRenderer.SetActiveCamera(aCamera)
aRenderer.ResetCamera()
aCamera.Dolly(1.5)

# Set a background color for the renderer and set the size of the
# render window (expressed in pixels).
aRenderer.SetBackground(colors.GetColor3d('BkgColor'))
renWin.SetSize(640, 480)
renWin.SetWindowName('MedicalDemo2')

# Note that when camera movement occurs (as it does in the Dolly()
# method), the clipping planes often need adjusting. Clipping planes
# consist of two planes: near and far along the view direction. The
# near plane clips out objects in front of the plane the far plane
# clips out objects behind the plane. This way only what is drawn
# between the planes is actually rendered.
aRenderer.ResetCameraClippingRange()

# Initialize the event loop and then start it.
iren.Initialize()
iren.Start()

def get_program_parameters():
import argparse
description = 'The skin and bone is extracted from a CT dataset of the head.'
epilogue = '''
Derived from VTK/Examples/Cxx/Medical2.cxx
This example reads a volume dataset, extracts two isosurfaces that
represent the skin and bone, and then displays it.
'''
parser = argparse.ArgumentParser(description=description, epilog=epilogue,
formatter_class=argparse.RawDescriptionHelpFormatter)