# VTK 9.0 Offscreen Rendering

**URL:** https://discourse.vtk.org/t/vtk-9-0-offscreen-rendering/3379
**Category:** Support
**Created:** [May 22, 2020, 9:57pm UTC](https://discourse.vtk.org/t/vtk-9-0-offscreen-rendering/3379 "2020-05-22T21:57:55Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![akaszynski](https://discourse.vtk.org/user_avatar/discourse.vtk.org/akaszynski/32/10751_2.png) [@akaszynski](https://discourse.vtk.org/u/akaszynski)
#### Post date: [May 22, 2020, 9:57pm UTC](https://discourse.vtk.org/t/vtk-9-0-offscreen-rendering/3379/1 "2020-05-22T21:57:55Z")

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Hello,

I’m seeing a significant slowdown when rending offscreen with VTK 9.0:

```python
ren_win.SetOffScreenRendering(1)

```

The rendered image looks better than the ones from \<VTK9.0, however for testing purposes the renders are taking a long time. As I’m currently using the default parameters for the render window, are there any non-default parameters to speed up the render?

Thanks for all your hard work!

---

<div class="post-metadata">

### Author: ![Juan\_C\_Prieto](https://discourse.vtk.org/user_avatar/discourse.vtk.org/juan_c_prieto/32/10633_2.png) [@Juan\_C\_Prieto](https://discourse.vtk.org/u/Juan_C_Prieto)
#### Post date: [October 4, 2020, 1:31am UTC](https://discourse.vtk.org/t/vtk-9-0-offscreen-rendering/3379/2 "2020-10-04T01:31:49Z")

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Do you call vtkRenderWindowInteractor::Initialize()?  
I noticed reduced speed when running offscreen rendering and not calling this function.

Best,