Problem with using vtkImagePlaneWidget & vtkPOpenFOAMReader - qt

Question

enter image description here
I used vtkPOpenFOAMReader to read *.foam.
And also I used vtkImagePlaneWidget to read dicom data to 3D show.
Everything is okay, I got the result. But there is a critical issue.
I can see foam data is perfect.
But if add only this code<(1)>, a broken line appears on foam data.
#include "mainwindow.h"
#include <QApplication>
#include <iostream>
using namespace std;
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);
VTK_MODULE_INIT(vtkRenderingFreeType);
int main(int argc, char *argv[])
{
vtkSmartPointer<vtkImagePlaneWidget> planeWidget = vtkSmartPointer<vtkImagePlaneWidget>::New();/*(1)*/
vtkSmartPointer<vtkPOpenFOAMReader>openFOAMReader = vtkSmartPointer<vtkPOpenFOAMReader>::New();
openFOAMReader->SetCaseType(0);
openFOAMReader->SetFileName("./PatientA/ffr.foam");
openFOAMReader->CreateCellToPointOn();
openFOAMReader->EnableAllCellArrays();
openFOAMReader->DecomposePolyhedraOn();
openFOAMReader->Update();
vtkSmartPointer< vtkGeometryFilter> filter = vtkSmartPointer<vtkGeometryFilter>::New();
filter->SetInputConnection(openFOAMReader->GetOutputPort());
vtkSmartPointer<vtkCompositePolyDataMapper2> mapper = vtkSmartPointer<vtkCompositePolyDataMapper2>::New();
mapper->SetInputConnection(filter->GetOutputPort());
mapper->SetScalarModeToUsePointFieldData();
mapper->SelectColorArray("p");
mapper->SetScalarRange(-10, 50);
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
renderer->AddActor(actor);
vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New();
renWin->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow(renWin);
renWin->Render();
iren->Start();
return true;
}
So why it is happened? It's a very critical issue for me.