# pick 3D Widgets in openGL window

**URL:** https://discourse.vtk.org/t/pick-3d-widgets-in-opengl-window/3717
**Category:** Support
**Created:** [July 7, 2020, 1:54pm UTC](https://discourse.vtk.org/t/pick-3d-widgets-in-opengl-window/3717 "2020-07-07T13:54:48Z")
**Posts on this page:** 1
**Page:** 1

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### 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: [July 7, 2020, 1:54pm UTC](https://discourse.vtk.org/t/pick-3d-widgets-in-opengl-window/3717/1 "2020-07-07T13:54:48Z")

</div>

Hi  
I have a 2D distance widget and 3D distance widget. I want to pick them by left button click. I’ve done well the distance widget on 2D image but I cannot pick the **3D** one( **vtkDistanceRepresentation3D** ) in opengl window.  
Here is my snippet. The path and picked actor is None. maybe my problem is I cannot set the correct 3d widget’s actor.

```
# add distance widget actor to picker list
interactor.GetPicker().AddPickList(measure_widget.GetDistanceRepresentation().GetGlyphActor())

def leftButtonPressEvent(self, obj, event):
        click_pos = self.GetInteractor().GetEventPosition()
        picker = self.GetInteractor().GetPicker()
        picker.Pick(click_pos[0], click_pos[1], 0, self.GetDefaultRenderer())
        path = picker.GetPath()
        # doen't go through if
        if path:
            node = path.GetFirstNode()
            actor = node.GetViewProp()

```

![Annotation 2020-07-07 181718](https://discourse.vtk.org/uploads/default/original/2X/1/17d27a3521d4ec0da07208cc4010b61a03f46e4c.jpeg)

I tried my interactor **default picker** and **vtkPropPicke** r and also **vtkPicker**.  
Can anyone help me to pick my 3D distance widget?  
Thank You