Features & Results

ENH : Add volumetric mesh support in vtkMRMLModelNod

Update vtkMRMLModelNode to store a vtkPointSet instead of a vtkPolyData. vtkPointSet can be a base class for vtkPolyData (surface mesh) as well as vtkUnstructuredGrid (volumetric mesh).

The safest way to know if the mesh is unstructuredGrid is to check if vtkMRMLModelNode::GetUnstructuredGrid() is not NULL, but since it requires to update the pipeline, vtkMRMLModelNode also has a member variable called MeshTypeHint.

For backward compatibility, keep the public polydata-based API and wrap around the mesh-based API.

Update vtkMRMLModelDisplayNode, vtkMRMLModelDisplayableManager, vtkMRMLModelSliceDisplayableManager, and qMRMLModelDisplayNodeWidget to use the mesh-based API.

ENH: Add support for vtkUnstructuredGrid IO

Update vtkMRMLModelStorageNode and qSlicerModelsReader to be able to read and write unstructured grid based models using the vtkUnstructuredGrid readers and writers (.vtk and .vtu).

Implement GetAssociatedDataNode() similar to the one in vtkMRMLSegmentationStorageNode to offer the correct supported write file types.

BUG: Read all data for model of .vtk extension

STYLE: Use actorProperties in Model displayable manager

ENH: Implement vtkMRMLProceduralColorNode::GetLookupTable

Migrate conversion of ColorTransferFunction to LookupTable from ModelDisplayableManager to ProceduralColorNode, to simplify code in the displayable manager, and to be able to reuse that conversion code for ModelSliceDisplayableManager.

ENH: Consolidate AutoScalarRange & ScalarRangeFlag

AutoScalarRange - in vtkMRMLDisplayNode - would define if the ModelDisplayNode would reset its ScalarRange to map the range of the mesh active scalar or not (manually set by the user).

ScalarRangeFlag - in vtkMRMLDisplayNode - would define if the ModelDisplayableManager would map scalar range based on the active scalar if UseDataScalarRange (same that AutoScalarOn), would use the DataType range if UseDataTypeScalarRange, would use the color node lookup table range if UseColorNodeScalarRange, or would use the display node scalar range (aka its OWN range defined by AutoScalarRange value) if UseDisplayNodeScalarRange.

To consolidate those two class members which show redundancies, they are replaced by a unique ScalarRangeFlag which can take the following values:

UseManualScalarRange (new, equivalent to AutoScalarRangeOff)
UseDataScalarRange (as previously, equivalent to AutoScalarRangeOn)
UseColorNodeScalarRange (as previously)
UseDataTypeScalarRange (as previously) Note the removal of UseDisplayNodeScalarRange.

For backward compatibility, the AutoScalarRange API is conserved and wraps Set/GetScalarRangeFlag.

The range update based on this ScalarRangeFlag is then made in vtkMRMLModelDisplayNode::UpdateMeshPipeline instead of vtkMRMLModelDisplayableManager::SetModelDisplayProperty, which simplifies greatly the code in the displayable manager by only calling mapper->SetScalarRange(modelDisplayNode->GetScalarRange()), and allows that call in vtkMRMLModelSliceDisplayableManager to now return the correct range based on that option.

vtkMRMLModelSliceDisplayableManager is also updated to instantiate the vtkMapper in a similar way than it is made in the 3D displayable manager for visualization consistency (deep copy of the lut, etc...)

ENH: Add Thresholding for vtkMRMLModelDisplayNode

ENH: Add model mesh type in qMRMLModelInfoWidget

Needed tests

Work made on vtkMRMLDisplayNode and vtkMRMLModelDisplayNode could impact a lot of classes. Should probably test with fiber bundles (@ihnorton ?).

Future work

Clean up and consolidate qSlicerModelsModuleWidget (display properties, representations, wireframe, clipping... just move options around to make it more usable)
Add clipping option to smoothen the cut (using vtkClipDataSet vs vtkExtractGeometry). Not urgent since the Slicer view can display a smooth cut.
Update extensions like CleaverExtension or BodyCentricCubicMesh module, import edition/creation work from IA_FEMesh.

Add Volumetric mesh support