# QVTKRenderWindowInteractor cause problem to draw vktDistanceWidget on vtkImageReslice

**URL:** https://discourse.vtk.org/t/qvtkrenderwindowinteractor-cause-problem-to-draw-vktdistancewidget-on-vtkimagereslice/2831
**Category:** Support
**Created:** [March 17, 2020, 8:31am UTC](https://discourse.vtk.org/t/qvtkrenderwindowinteractor-cause-problem-to-draw-vktdistancewidget-on-vtkimagereslice/2831 "2020-03-17T08:31:50Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![kimia.af1998](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/k/7ab992/32.png) [@kimia.af1998](https://discourse.vtk.org/u/kimia.af1998)
#### Post date: [March 17, 2020, 8:31am UTC](https://discourse.vtk.org/t/qvtkrenderwindowinteractor-cause-problem-to-draw-vktdistancewidget-on-vtkimagereslice/2831/1 "2020-03-17T08:31:50Z")

</div>

Hi.  
I’ve been displaying **DICOM** series slices(vtkImageReslice output) on **QVTKRenderWindowInteractor** but when I want to use vtkDistanceWidget to measure two selected points by mouse event, It doesn’t work and nothing appears.  
with out QVTKRenderWindowInteractor it works but I want to embed pyqt5.  
Here is my snippet:

```
        widget = QVTKRenderWindowInteractor() # This interactor contains renderer and actors
        renderWindow = widget.GetRenderWindow()
        renderWindow.AddRenderer(renderer)

        # An interactor
        widget.GetRenderWindow().GetInteractor().SetInteractorStyle(vtk.vtkInteractorStyleTrackballCamera())
        renderWindowInteractor = widget.GetRenderWindow().GetInteractor()
        distanceWidget = vtk.vtkDistanceWidget()
        distanceWidget.SetInteractor(renderWindowInteractor)
        distanceWidget.CreateDefaultRepresentation()
        renderWindowInteractor.Initialize()
        renderWindow.Render()
        distanceWidget.On()

        renderWindowInteractor.Start()
```