# vtkResliceCursorWidget compatibility with QT QVTKWidget
**URL:** https://discourse.vtk.org/t/vtkreslicecursorwidget-compatibility-with-qt-qvtkwidget/8562
**Category:** Development
**Created:** [May 24, 2022, 1:17am UTC](https://discourse.vtk.org/t/vtkreslicecursorwidget-compatibility-with-qt-qvtkwidget/8562 "2022-05-24T01:17:15Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Alexandera](https://discourse.vtk.org/u/Alexandera)
#### Post date: [May 24, 2022, 1:17am UTC](https://discourse.vtk.org/t/vtkreslicecursorwidget-compatibility-with-qt-qvtkwidget/8562/1 "2022-05-24T01:17:15Z")
Hi,
I am working on the medical GUI development with QT and VTK. I have made MPR (MultiPlanar reformation) in VTK alone, but it does not show when I show it in QT (basically I add the renderwindow and renderer to QVTKWidget). I also tried QVTKOpenGLNativeWidget as an option, but it does not work as well. I knew it needs vtkGenericOpenGLRenderWindow where for display.
###coding environment:
QT5.9 VS2017 VTK8.2.0
Could you share you experience with QT+VTK…thanks!
###alone:
###in QT:
###here is my code
```cpp
void BorderWidgetQt::openMPRwindow(QVTKWidget* qvtkwidget) {
QVTKInteractor* iren = qvtkwidget->GetInteractor();
vtkRenderWindow* renWin = qvtkwidget->GetRenderWindow();
vtkSmartPointer reader = vtkSmartPointer::New();
reader->SetDirectoryName("C:\\Users\\u\\source\\repos\\myrobotapp\\DICOM");
reader->Update();
vtkSmartPointer ren; //vtksmartpointer
//vtkSmartPointer renWin = vtkSmartPointer::New();
renWin->SetMultiSamples(0);
ren = vtkSmartPointer::New();
renWin->AddRenderer(ren);
//vtkSmartPointer iren = vtkSmartPointer::New();
iren->SetRenderWindow(renWin);
//renWin->SetInteractor(iren);
vtkSmartPointer ipwProp = vtkSmartPointer::New();
int imageDims[3];
reader->GetOutput()->GetDimensions(imageDims);
for (int i = 0; i < 3; i++) {
std::cout << "imagesize L X W X H: " << imageDims[i] << std::endl;
}
vtkSmartPointer< vtkResliceCursor > resliceCursor = vtkSmartPointer< vtkResliceCursor >::New();
resliceCursor->SetCenter(reader->GetOutput()->GetCenter());
resliceCursor->SetThickMode(1);// mode 1 or more and thickness can be viewed
//set image that are resliced
resliceCursor->SetImage(reader->GetOutput());
vtkSmartPointer< vtkResliceCursorWidget > resliceCursorWidget;
vtkSmartPointer< vtkResliceCursorLineRepresentation > resliceCursorRep;
//camera viewup
double viewUp[3][3] = { { 1, 0, -1 }, { 0, 0, 1 }, { 0, 1, 0 } };
/ ************************ /
resliceCursorWidget = vtkSmartPointer< vtkResliceCursorWidget >::New();
resliceCursorWidget->SetInteractor(iren);
resliceCursorRep = vtkSmartPointer< vtkResliceCursorLineRepresentation >::New();
resliceCursorWidget->SetRepresentation(resliceCursorRep);
resliceCursorRep->GetResliceCursorActor()->GetCursorAlgorithm()->SetResliceCursor(resliceCursor);
//thickness text is ediable and can turn off
//resliceCursorRep->DisplayTextOff();
resliceCursorRep->GetResliceCursorActor()->GetCursorAlgorithm()->SetReslicePlaneNormal(0);
cout << "number of input port: " << resliceCursorRep->GetResliceCursorActor()->GetCursorAlgorithm() << endl;
const double minVal = reader->GetOutput()->GetScalarRange()[0];
std::cout << "minVal: " << minVal << " maxVal: " << reader->GetOutput()->GetScalarRange()[1] << endl; //0~1059
if (vtkImageReslice *reslice = vtkImageReslice::SafeDownCast(resliceCursorRep->GetReslice()))
{
reslice->SetBackgroundColor(minVal, minVal, minVal, minVal);
}
resliceCursorWidget->SetDefaultRenderer(ren);
resliceCursorWidget->SetEnabled(1);
ren->GetActiveCamera()->SetFocalPoint(0, 0, 0);
double camPos[3] = { 1, 0, 0 };
ren->GetActiveCamera()->SetPosition(camPos);
ren->GetActiveCamera()->ParallelProjectionOn();
ren->GetActiveCamera()->SetViewUp(viewUp[0][0], viewUp[0][1], viewUp[0][2]);
ren->ResetCamera();
double range[2];
reader->GetOutput()->GetScalarRange(range);
std::cout << "range[0]: " << range[0] << " range[1]: " << range[1] << endl; // 0~1059
//cover full range of window
resliceCursorRep->SetWindowLevel(range[1] - range[0], (range[0] + range[1]) / 2.0);
//resliceCursorRep->SetLookupTable(resliceCursorRep->GetLookupTable());
//reslice cursor center
vtkResliceCursor *rc = resliceCursorRep->GetResliceCursorActor()->GetCursorAlgorithm()->GetResliceCursor();
double *center = rc->GetCenter();
std::cout << "cursor center: " << " [x]: "
<< center[0] << " [y]: " << center[1] << " [z]: " << center[2] << endl;
/ ************************ /
//background of window
ren->SetBackground(0.3, 0.1, 0.1);
//whether it is a hole in the center of two cross hair
resliceCursor->SetHole(0);
resliceCursor->SetThickness(2, 2, 2);
cout << "thickness is : " << resliceCursor->GetThickness()[0] << endl;
vtkSmartPointer< vtkInteractorStyleImage > style = vtkSmartPointer< vtkInteractorStyleImage >::New();
iren->SetInteractorStyle(style);
renWin->Render();
//iren->Initialize();
//iren->Start();
}
```
---
### Author:  [@Alexandera](https://discourse.vtk.org/u/Alexandera)
#### Post date: [May 24, 2022, 3:18am UTC](https://discourse.vtk.org/t/vtkreslicecursorwidget-compatibility-with-qt-qvtkwidget/8562/2 "2022-05-24T03:18:40Z")
it was solved when I just claim the following in head file and make corresponding change in cpp:
private:
vtkSmartPointer\< vtkResliceCursorWidget \> resliceCursorWidget;
I dont know the deepth of the solution. Maybe the QT cannot read the source file if it is not claimed, and also it needs timely render the source. I just closed this question.
