pearsonm
February 22, 2023, 12:23am
1
Hi,
I am writing a module to process dynamic nuclear medicine images and I have an issue that might be a bug.
I load 2 DICOM datasets as vtkMRMLScalarVolumeNode but another module also creates a vtkMRMLMultiVolumeNode.
If I try to filter by GetNodesByClass all 3 nodes are returned. Is this the expected behavior?
>>> slicer.mrmlScene.GetNodesByClass('vtkMRMLMultiVolumeNode').GetNumberOfItems()
1
>>> slicer.mrmlScene.GetNodesByClass('vtkMRMLScalarVolumeNode').GetNumberOfItems()
3
Tested on Slicer stable and 5.3.0-2023-02-21
Mark
What you’ve discovered is that vtkMRMLMultiVolumeNode is derived from vtkMRMLScalarVolumeNode. It is a type of vtkMRMLScalarVolumeNode.
If in your module you utilize a qMRMLNodeComboBox for selecting certain nodes in the mrml scene, you can specify to have show child nodes set to off which would exclude vtkMRMLMultiVolumeNodes from populating in this widget.
/// bypass the property and show the node anyway.
inline void setShowHidden(bool);
inline bool showHidden()const;
/// This property controls whether subclasses of \a nodeType
/// are hidden or not. If false, only the nodes of 'final' type
/// is \a nodeType are displayed, if true, all the nodes deriving
/// from \a nodeType are visible except for the ones of
/// type \a hideChildNodeTypes.
/// true by default.
inline void setShowChildNodeTypes(bool show);
inline bool showChildNodeTypes()const;
/// If a node is a nodeType, hide the node if it is also
/// a ExcludedChildNodeType. (this can happen if nodeType is a
/// mother class of ExcludedChildNodeType)
inline void setHideChildNodeTypes(const QStringList& nodeTypes);
inline QStringList hideChildNodeTypes()const;
/// Add node type attribute that filter the nodes to
/// display. For example, colormap categories are defined with the "Category"
I don’t believe the GetNodesByClass method has an option to exclude child nodes from being found. Therefore you might have to do this exclusion on your own afterwards.
pearsonm
February 22, 2023, 3:32am
3
Thanks,
In that case I will add a filter for ‘MultiVolume’ in GetClassName on my list of nodes.