# VTK interactor window opens but regular render window won't

**URL:** https://discourse.vtk.org/t/vtk-interactor-window-opens-but-regular-render-window-wont/7917
**Category:** Support
**Created:** [February 24, 2022, 6:11pm UTC](https://discourse.vtk.org/t/vtk-interactor-window-opens-but-regular-render-window-wont/7917 "2022-02-24T18:11:18Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![pbaudin](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/p/48db29/32.png) [@pbaudin](https://discourse.vtk.org/u/pbaudin)
#### Post date: [February 24, 2022, 6:11pm UTC](https://discourse.vtk.org/t/vtk-interactor-window-opens-but-regular-render-window-wont/7917/1 "2022-02-24T18:11:18Z")

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Hi everyone,

I’m new to VTK and I’m trying to get started in python 3.10.2 in a conda environment. On a 2020 M1 Macbook Air

I’m working on just running some minimal examples and I’ve noticed something odd.

The following code example runs as expected [https://kitware.github.io/vtk-examples/site/Python/GeometricObjects/CylinderExample/](https://kitware.github.io/vtk-examples/site/Python/GeometricObjects/CylinderExample/)

But this provided tutorial code runs without error but doesn’t open a render window:  
[https://kitware.github.io/vtk-examples/site/Python/Tutorial/Tutorial\_Step1/](https://kitware.github.io/vtk-examples/site/Python/Tutorial/Tutorial_Step1/)

The difference is that the “Hello World” example uses the vtkRenderWindowInteractor() object, and the “Tutorial\_Step1” example only uses the vtkRenderWindow() object. That code is meant to show the render window and make the a 3D cone rotate once and then exit.

I can make the tutorial code work by adding an vtkRenderWindowInteractor() object, but I am concerned about moving forward when there seems to be a problem with rendering windows without the interactor.

Has anybody dealt with this issue?

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<div class="post-metadata">

### Author: ![zhang-qiang-github](https://discourse.vtk.org/user_avatar/discourse.vtk.org/zhang-qiang-github/32/2519_2.png) [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)
#### Post date: [February 25, 2022, 1:37am UTC](https://discourse.vtk.org/t/vtk-interactor-window-opens-but-regular-render-window-wont/7917/2 "2022-02-25T01:37:46Z")

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> [@pbaudin](#):
>
> That code is meant to show the render window and make the a 3D cone rotate once and then exit.

That is what `Tutorial_Step1` want to do, and it also the reason why it exit because all the work has been done.

If you want to interect with the window, you need to add `vtkRenderWindowInteractor`. If not, you do not need to add it.

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<div class="post-metadata">

### Author: ![pbaudin](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/p/48db29/32.png) [@pbaudin](https://discourse.vtk.org/u/pbaudin)
#### Post date: [February 25, 2022, 3:25pm UTC](https://discourse.vtk.org/t/vtk-interactor-window-opens-but-regular-render-window-wont/7917/3 "2022-02-25T15:25:17Z")

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I understand that the tutorial code is supposed to open a render window, rotate a cone, and then exit.

What I’m saying is that it doesn’t open a window. A window only opens if I have an interacter object.

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### Author: ![brandonfosso](https://discourse.vtk.org/user_avatar/discourse.vtk.org/brandonfosso/32/4951_2.png) [@brandonfosso](https://discourse.vtk.org/u/brandonfosso)
#### Post date: [April 6, 2022, 7:51pm UTC](https://discourse.vtk.org/t/vtk-interactor-window-opens-but-regular-render-window-wont/7917/4 "2022-04-06T19:51:19Z")

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I am seeing this same behavior.

No window spawns when the basic example is run. It completes without errors.

An example with an interactive window works.