# Multi vtkRenderWindow Rendering Issues
**URL:** https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373
**Category:** Support
**Created:** [May 4, 2023, 8:09am UTC](https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373 "2023-05-04T08:09:53Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@a772485252](https://discourse.vtk.org/u/a772485252)
#### Post date: [May 4, 2023, 8:09am UTC](https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373/1 "2023-05-04T08:09:53Z")
Hello everyone, I have a question.
I have four vtkRenderWindows, one of which has a timer that helps me continuously render something when I start it. At this point, when I interact with other windows, it will block rendering in the timer. My question is, is it not possible to render multiple windows simultaneously. Or perhaps my design is unreasonable. Should I not use multiple renderwindows?
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### Author:  [@Sebastien\_Jourdain](https://discourse.vtk.org/u/Sebastien_Jourdain)
#### Post date: [May 6, 2023, 5:44pm UTC](https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373/2 "2023-05-06T17:44:49Z")
The way to handle it would be to use 1 render window with many renderer/viewport.
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### Author:  [@a772485252](https://discourse.vtk.org/u/a772485252)
#### Post date: [May 8, 2023, 1:27am UTC](https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373/3 "2023-05-08T01:27:45Z")
Oh okay, thank you. Actually, I need to layout the four windows or add other controls.
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### Author:  [@Sebastien\_Jourdain](https://discourse.vtk.org/u/Sebastien_Jourdain)
#### Post date: [May 8, 2023, 2:20pm UTC](https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373/4 "2023-05-08T14:20:41Z")
Well I was assuming a contiguous set of “windows” (vtkRenderer) inside a single vtkRenderWindow.
Each vtkRenderer can have specific location within that single vtkRenderWindow.
But that suggestion was just to allow a single render for all your “windows”. This may not work if your “windows” are far apart…
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### Author:  [@a772485252](https://discourse.vtk.org/u/a772485252)
#### Post date: [May 9, 2023, 5:13am UTC](https://discourse.vtk.org/t/multi-vtkrenderwindow-rendering-issues/11373/5 "2023-05-09T05:13:38Z")
Okay, I’ll think about it again. Thank you very much for your answer!