Thanks for posting that - it does look like most of the time is spent executing the scissors, so maybe there’s a very inefficient code path that stalls on mac.
@lassoan is there a test for the scissors so we can compare the exact operation on multiple platforms?
+ 2564 qMRMLSegmentEditorWidget::processEvents(vtkObject*, unsigned long, void*, void*) (in libqSlicerSegmentationsModuleWidgets.dylib) + 382 [0x128e29b5e]
+ 2564 qSlicerSegmentEditorScissorsEffect::processInteractionEvents(vtkRenderWindowInteractor*, unsigned long, qMRMLWidget*) (in libqSlicerSegmentationsEditorEffects.dylib) + 445 [0x128fc1a2d]
+ 2564 qSlicerSegmentEditorScissorsEffectPrivate::paintApply(qMRMLWidget*) (in libqSlicerSegmentationsEditorEffects.dylib) + 205 [0x128fbe1dd]
+ 2564 vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) (in libvtkCommon-8.2.1.dylib) + 254 [0x11c3f3d8e]
+ 2564 vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) (in libvtkCommon-8.2.1.dylib) + 1120 [0x11c3f39a0]
+ 2564 vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) (in libvtkCommon-8.2.1.dylib) + 1228 [0x11c3cd61c]
+ 2564 vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) (in libvtkCommon-8.2.1.dylib) + 107 [0x11c3c885b]
+ 2564 vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) (in libvtkCommon-8.2.1.dylib) + 61 [0x11c3cde9d]
+ 2564 vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) (in libvtkCommon-8.2.1.dylib) + 69 [0x11c3d32c5]
+ 2564 vtkImageStencilAlgorithm::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) (in libvtkImaging-8.2.1.dylib) + 65 [0x11bade4a1]
+ 2564 vtkPolyDataToImageStencil::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) (in libvtkImaging-8.2.1.dylib) + 139 [0x11bd0281b]
+ 1284 vtkPolyDataToImageStencil::ThreadedExecute(vtkImageStencilData*, int*, int) (in libvtkImaging-8.2.1.dylib) + 2523 [0x11bd01efb]
+ ! 1013 vtkAOSDataArrayTemplate<float>::GetTuple(long long, double*) (in libvtkCommon-8.2.1.dylib) + 217,28,... [0x11bfa8519,0x11bfa845c,...]
+ ! 271 vtkStructuredGrid::GetPoint(long long, double*) (in libvtkCommon-8.2.1.dylib) + 0,11,... [0x11c28bb90,0x11c28bb9b,...]
+ 1147 vtkPolyDataToImageStencil::ThreadedExecute(vtkImageStencilData*, int*, int) (in libvtkImaging-8.2.1.dylib) + 2595,2603,... [0x11bd01f43,0x11bd01f4b,...]
+ 131 vtkStructuredGrid::GetPoint(long long, double*) (in libvtkCommon-8.2.1.dylib) + 26 [0x11c28bbaa]
+ 2 vtkPolyDataToImageStencil::ThreadedExecute(vtkImageStencilData*, int*, int) (in libvtkImaging-8.2.1.dylib) + 2250 [0x11bd01dea]
+ 2 vtkAOSDataArrayTemplate<float>::GetTuple(long long, double*) (in libvtkCommon-8.2.1.dylib) + 213,217 [0x11bfa8515,0x11bfa8519]