vtkResliceCursorWidget: output images are cropped

Do you mean that the line is not always visible? It’s probably related to this issue: https://gitlab.kitware.com/vtk/vtk/-/issues/18441

Using the following properties for the lines should fix it:

    resliceCursorRep[i]->GetResliceCursorActor()->GetCenterlineProperty(0)->SetRepresentationToWireframe();
    resliceCursorRep[i]->GetResliceCursorActor()->GetCenterlineProperty(1)->SetRepresentationToWireframe();
    resliceCursorRep[i]->GetResliceCursorActor()->GetCenterlineProperty(2)->SetRepresentationToWireframe();