Slicer学习笔记（五十一）slicer python扩展中在3D视图显示信息

1、Display text in a 3D view or slice view

The easiest way to show information overlaid on a viewer is to use corner annotations.

view=slicer.app.layoutManager().threeDWidget(0).threeDView()
# Set text to "Something"
view.cornerAnnotation().SetText(vtk.vtkCornerAnnotation.UpperRight,"Something")
# Set color to red
view.cornerAnnotation().GetTextProperty().SetColor(1,0,0)
# Update the view
view.forceRender()

显示效果：
可以看到在右上角显示了字符串 红色的“something”。

To display text in slice views, replace the first line by this line (and consider hiding slice view annotations, to prevent them from overwriting the text you place there):

view=slicer.app.layoutManager().sliceWidget("Red").sliceView()

参考：Display text in a 3D view or slice view

2、显示体绘制 VolumeRendering

Show volume rendering automatically when a volume is loaded

To show volume rendering of a volume automatically when it is loaded, add the lines below to your .slicerrc.py file.

@vtk.calldata_type(vtk.VTK_OBJECT)
def onNodeAdded(caller, event, calldata):
  node = calldata
  if isinstance(node, slicer.vtkMRMLVolumeNode):
    # Call showVolumeRendering using a timer instead of calling it directly
    # to allow the volume loading to fully complete.
    qt.QTimer.singleShot(0, lambda: showVolumeRendering(node))

def showVolumeRendering(volumeNode):
  print("Show volume rendering of node " + volumeNode.GetName())
  volRenLogic = slicer.modules.volumerendering.logic()
  displayNode = volRenLogic.CreateDefaultVolumeRenderingNodes(volumeNode)
  displayNode.SetVisibility(True)
  scalarRange = volumeNode.GetImageData().GetScalarRange()
  if scalarRange[1]-scalarRange[0] < 1500:
    # Small dynamic range, probably MRI
    displayNode.GetVolumePropertyNode().Copy(volRenLogic.GetPresetByName("MR-Default"))
  else:
    # Larger dynamic range, probably CT
    displayNode.GetVolumePropertyNode().Copy(volRenLogic.GetPresetByName("CT-Chest-Contrast-Enhanced"))

slicer.mrmlScene.AddObserver(slicer.vtkMRMLScene.NodeAddedEvent, onNodeAdded)

Show volume rendering using maximum intensity projection

def showVolumeRenderingMIP(volumeNode, useSliceViewColors=True):
  """Render volume using maximum intensity projection
  :param useSliceViewColors: use the same colors as in slice views.
  """
  # Get/create volume rendering display node
  volRenLogic = slicer.modules.volumerendering.logic()
  displayNode = volRenLogic.GetFirstVolumeRenderingDisplayNode(volumeNode)
  if not displayNode:
    displayNode = volRenLogic.CreateDefaultVolumeRenderingNodes(volumeNode)
  # Choose MIP volume rendering preset
  if useSliceViewColors:
    volRenLogic.CopyDisplayToVolumeRenderingDisplayNode(displayNode)
  else:
    scalarRange = volumeNode.GetImageData().GetScalarRange()
    if scalarRange[1]-scalarRange[0] < 1500:
      # Small dynamic range, probably MRI
      displayNode.GetVolumePropertyNode().Copy(volRenLogic.GetPresetByName("MR-MIP"))
    else:
      # Larger dynamic range, probably CT
      displayNode.GetVolumePropertyNode().Copy(volRenLogic.GetPresetByName("CT-MIP"))
  # Switch views to MIP mode
  for viewNode in slicer.util.getNodesByClass("vtkMRMLViewNode"):
    viewNode.SetRaycastTechnique(slicer.vtkMRMLViewNode.MaximumIntensityProjection)
  # Show volume rendering
  displayNode.SetVisibility(True)

volumeNode = slicer.mrmlScene.GetFirstNodeByClass("vtkMRMLScalarVolumeNode")
showVolumeRenderingMIP(volumeNode)

Show volume rendering making soft tissues transparent

def showTransparentRendering(volumeNode, maxOpacity=0.2, gradientThreshold=30.0):
  """Make constant regions transparent and the entire volume somewhat transparent
  :param maxOpacity: lower value makes the volume more transparent overall
    (value is between 0.0 and 1.0)
  :param gradientThreshold: regions that has gradient value below this threshold will be made transparent
    (minimum value is 0.0, higher values make more tissues transparent, starting with soft tissues)
  """
  # Get/create volume rendering display node
  volRenLogic = slicer.modules.volumerendering.logic()
  displayNode = volRenLogic.GetFirstVolumeRenderingDisplayNode(volumeNode)
  if not displayNode:
    displayNode = volRenLogic.CreateDefaultVolumeRenderingNodes(volumeNode)
  # Set up gradient vs opacity transfer function
  gradientOpacityTransferFunction = displayNode.GetVolumePropertyNode().GetVolumeProperty().GetGradientOpacity()
  gradientOpacityTransferFunction.RemoveAllPoints()
  gradientOpacityTransferFunction.AddPoint(0, 0.0)
  gradientOpacityTransferFunction.AddPoint(gradientThreshold-1, 0.0)
  gradientOpacityTransferFunction.AddPoint(gradientThreshold+1, maxOpacity)
  # Show volume rendering
  displayNode.SetVisibility(True)

volumeNode = slicer.mrmlScene.GetFirstNodeByClass("vtkMRMLScalarVolumeNode")
showTransparentRendering(volumeNode, 0.2, 30.0)

Display volume using volume rendering

  logic = slicer.modules.volumerendering.logic()
  volumeNode = slicer.mrmlScene.GetNodeByID('vtkMRMLScalarVolumeNode1')
  displayNode = logic.CreateVolumeRenderingDisplayNode()
  displayNode.UnRegister(logic)
  slicer.mrmlScene.AddNode(displayNode)
  volumeNode.AddAndObserveDisplayNodeID(displayNode.GetID())
  logic.UpdateDisplayNodeFromVolumeNode(displayNode, volumeNode)

3、测试体绘制效果

def showVolumeRendering(volumeNode):
  print("Show volume rendering of node " + volumeNode.GetName())
  volRenLogic = slicer.modules.volumerendering.logic()
  displayNode = volRenLogic.CreateDefaultVolumeRenderingNodes(volumeNode)
  displayNode.SetVisibility(True)

主要用于3D 视图的显示。

参考：Show volume rendering making soft tissues transparent