Mouse over in QML project

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1

Hi everyone,

I’am trying to use vtk in a QML project.
I’d like to highlight faces, edges or vertex on the mouse move hover event.

I use VTK 9.3.0.rc1

But it seems that it isn’t implemented in VTK as I can see in QVTKInteractorAdapter::ProcessEvent
Almost every QEvent are handled but not QEvent::HoverMove.

So I’ve tried a workaround using QML: I put a MouseArea over my object inherited by QQuickVTKItem, when the MouseArea trigger the onPositionChanged it calls my function that tried to highlight what’s under the mouse using a vtkCellPicker.

It works for a while but suddenly it randomly crash in some VTK code, most of the time on unverified nullptr…

Here is some QML code:

    MouseArea {
        anchors.fill: stepViewer
        hoverEnabled: true
        propagateComposedEvents: true
        acceptedButtons : Qt.NoButton
        onPositionChanged: {
            mouse.accepted = false
            myVTKViewer.highlightSubPoly(mouseX, height - mouseY)
        }
    }

Then the code I use to highlight what I get from the picker:
Nota: vtkPolyData* m_polyData;

	 // Clear selection
	 vtkIntArray* cellData = vtkIntArray::SafeDownCast(m_polyData->GetCellData()->GetScalars());
	 cellData->Fill(UNSELECTED_CELL); // <= value I use to color the unselected cells
...
	for (vtkIdType id : triIDS) // <= triIDS contains all cells I want to select
		cellData->SetValue(id, HIGHLIGHTED_CELL); // <= value I use to color the highlighted cells

	 cellData->Modified();

If there is any change in highlighted cells I call scheduleRender(); from my QQuickVTKItem.

What did I do wrong ?
Is there another way to achieve what I tried to do?