#!/usr/bin/env python # This example reads a volume dataset, extracts two isosurfaces that # represent the skin and bone, creates three orthogonal planes # (sagittal, axial, coronal), and displays them. import vtk from vtk.util.misc import vtkGetDataRoot VTK_DATA_ROOT = vtkGetDataRoot() # 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 scene. aRenderer = vtk.vtkRenderer() renWin = vtk.vtkRenderWindow() renWin.AddRenderer(aRenderer) 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 # usese 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.) v16 = vtk.vtkVolume16Reader() v16.SetDataDimensions(64, 64) v16.SetDataByteOrderToLittleEndian() v16.SetFilePrefix(VTK_DATA_ROOT + "/Data/headsq/quarter") v16.SetImageRange(1, 93) v16.SetDataSpacing(3.2, 3.2, 1.5) # An isosurface, or contour value of 500 is known to correspond to the # skin of the patient. Once generated, a vtkPolyDataNormals filter is # is used to create normals for smooth surface shading during rendering. # The triangle stripper is used to create triangle strips from the # isosurface these render much faster on may systems. skinExtractor = vtk.vtkContourFilter() skinExtractor.SetInputConnection(v16.GetOutputPort()) skinExtractor.SetValue(0, 500) skinNormals = vtk.vtkPolyDataNormals() skinNormals.SetInputConnection(skinExtractor.GetOutputPort()) skinNormals.SetFeatureAngle(60.0) skinStripper = vtk.vtkStripper() skinStripper.SetInputConnection(skinNormals.GetOutputPort()) skinMapper = vtk.vtkPolyDataMapper() skinMapper.SetInputConnection(skinStripper.GetOutputPort()) skinMapper.ScalarVisibilityOff() skin = vtk.vtkActor() skin.SetMapper(skinMapper) skin.GetProperty().SetDiffuseColor(1, .49, .25) skin.GetProperty().SetSpecular(.3) skin.GetProperty().SetSpecularPower(20) # An isosurface, or contour value of 1150 is known to correspond to the # skin of the patient. Once generated, a vtkPolyDataNormals filter is # is used to create normals for smooth surface shading during rendering. # The triangle stripper is used to create triangle strips from the # isosurface these render much faster on may systems. boneExtractor = vtk.vtkContourFilter() boneExtractor.SetInputConnection(v16.GetOutputPort()) boneExtractor.SetValue(0, 1150) boneNormals = vtk.vtkPolyDataNormals() boneNormals.SetInputConnection(boneExtractor.GetOutputPort()) boneNormals.SetFeatureAngle(60.0) boneStripper = vtk.vtkStripper() boneStripper.SetInputConnection(boneNormals.GetOutputPort()) boneMapper = vtk.vtkPolyDataMapper() boneMapper.SetInputConnection(boneStripper.GetOutputPort()) boneMapper.ScalarVisibilityOff() bone = vtk.vtkActor() bone.SetMapper(boneMapper) bone.GetProperty().SetDiffuseColor(1, 1, .9412) # An outline provides context around the data. outlineData = vtk.vtkOutlineFilter() outlineData.SetInputConnection(v16.GetOutputPort()) mapOutline = vtk.vtkPolyDataMapper() mapOutline.SetInputConnection(outlineData.GetOutputPort()) outline = vtk.vtkActor() outline.SetMapper(mapOutline) outline.GetProperty().SetColor(0, 0, 0) # Now we are creating three orthogonal planes passing through the # volume. Each plane uses a different texture map and therefore has # diferent coloration. # Start by creatin a black/white lookup table. bwLut = vtk.vtkLookupTable() bwLut.SetTableRange(0, 2000) bwLut.SetSaturationRange(0, 0) bwLut.SetHueRange(0, 0) bwLut.SetValueRange(0, 1) bwLut.Build() # Now create a lookup table that consists of the full hue circle (from # HSV). hueLut = vtk.vtkLookupTable() hueLut.SetTableRange(0, 2000) hueLut.SetHueRange(0, 1) hueLut.SetSaturationRange(1, 1) hueLut.SetValueRange(1, 1) hueLut.Build() # Finally, create a lookup table with a single hue but having a range # in the saturation of the hue. satLut = vtk.vtkLookupTable() satLut.SetTableRange(0, 2000) satLut.SetHueRange(.6, .6) satLut.SetSaturationRange(0, 1) satLut.SetValueRange(1, 1) satLut.Build() # Create the first of the three planes. The filter vtkImageMapToColors # maps the data through the corresponding lookup table created above. # The vtkImageActor is a type of vtkProp and conveniently displays an # image on a single quadrilateral plane. It does this using texture # mapping and as a result is quite fast. (Note: the input image has to # be unsigned char values, which the vtkImageMapToColors produces.) # Note also that by specifying the DisplayExtent, the pipeline # requests data of this extent and the vtkImageMapToColors only # processes a slice of data. sagittalColors = vtk.vtkImageMapToColors() sagittalColors.SetInputConnection(v16.GetOutputPort()) sagittalColors.SetLookupTable(bwLut) sagittal = vtk.vtkImageActor() sagittal.GetMapper().SetInputConnection(sagittalColors.GetOutputPort()) sagittal.SetDisplayExtent(32, 32, 0, 63, 0, 92) # Create the second (axial) plane of the three planes. We use the same # approach as before except that the extent differs. axialColors = vtk.vtkImageMapToColors() axialColors.SetInputConnection(v16.GetOutputPort()) axialColors.SetLookupTable(hueLut) axial = vtk.vtkImageActor() axial.GetMapper().SetInputConnection(axialColors.GetOutputPort()) axial.SetDisplayExtent(0, 63, 0, 63, 46, 46) # Create the third (coronal) plane of the three planes. We use the same # approach as before except that the extent differs. coronalColors = vtk.vtkImageMapToColors() coronalColors.SetInputConnection(v16.GetOutputPort()) coronalColors.SetLookupTable(satLut) coronal = vtk.vtkImageActor() coronal.GetMapper().SetInputConnection(coronalColors.GetOutputPort()) coronal.SetDisplayExtent(0, 63, 32, 32, 0, 92) # 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() # Actors are added to the renderer. aRenderer.AddActor(outline) aRenderer.AddActor(sagittal) aRenderer.AddActor(axial) aRenderer.AddActor(coronal) #aRenderer.AddActor(axial) #aRenderer.AddActor(coronal) aRenderer.AddActor(skin) aRenderer.AddActor(bone) # Turn off bone for this example. bone.VisibilityOff() # Set skin to semi-transparent. skin.GetProperty().SetOpacity(0.5) # 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(1, 1, 1) renWin.SetSize(640, 480) # 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() # Interact with the data. iren.Initialize() renWin.Render() iren.Start()
