# Status Update: Runtime OpenGL render window selection in VTK

**URL:** https://discourse.vtk.org/t/status-update-runtime-opengl-render-window-selection-in-vtk/14583
**Category:** Announcements
**Created:** [September 16, 2024, 5:51pm UTC](https://discourse.vtk.org/t/status-update-runtime-opengl-render-window-selection-in-vtk/14583 "2024-09-16T17:51:42Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![jaswantp](https://discourse.vtk.org/user_avatar/discourse.vtk.org/jaswantp/32/10046_2.png) [@jaswantp](https://discourse.vtk.org/u/jaswantp)
#### Post date: [September 16, 2024, 5:51pm UTC](https://discourse.vtk.org/t/status-update-runtime-opengl-render-window-selection-in-vtk/14583/1 "2024-09-16T17:51:42Z")

</div>

Hi,

I’m happy to share that we have simplified the OpenGL window system logic in VTK so developers can rely on a single `vtk` build for deployments in both cloud and desktop.

# How does this impact consumers of VTK?

Starting from [VTK 9.4, scheduled for November, 2024](https://discourse.vtk.org/t/vtk-9-4-0-release/14577), your project can rely on just a single `vtk` package for onscreen, offscreen and headless rendering. In the past, for cloud deployments that used `vtk` python wheel, you had to uninstall `vtk` and re-install `vtk-osmesa` or `vtk-egl`. Furthermore, you had to get those from [wheels.vtk.org](http://wheels.vtk.org), whereas now you would get headless and offscreen support directly from the `vtk` wheel in [pypi.org](http://pypi.org)!

# Technical details

## Linux

There is going to be only one wheel instead of three separate wheels. This new wheel is flexible and can fallback to EGL/OSMesa at runtime. If you’re a maintainer of a project depending on VTK, please remind your users to have valid OpenGL drivers. On linux, `libEGL` or `libOSMesa` can be installed from the package manager.

## Windows

In windows, there will now be only one wheel. Users interested in software-based headless rendering can download `osmesa.dll` from [Releases · pal1000/mesa-dist-win · GitHub](https://github.com/pal1000/mesa-dist-win/releases)

## Relevant links

1. Initial announcement: [Simplified python wheel for VTK](https://discourse.vtk.org/t/simplified-python-wheel-for-vtk/14329)
2. Release note: [https://gitlab.kitware.com/vtk/vtk/-/blob/master/Documentation/release/dev/support-runtime-opengl-window-selection.md](https://gitlab.kitware.com/vtk/vtk/-/blob/master/Documentation/release/dev/support-runtime-opengl-window-selection.md)
3. New runtime options: [Runtime settings - VTK documentation](https://docs.vtk.org/en/latest/advanced/runtime_settings.html)
4. OpenGL selection process: [Build Settings - VTK documentation](https://docs.vtk.org/en/latest/build_instructions/build_settings.html#additional-rendering-related-build-options)
5. MR - [https://gitlab.kitware.com/vtk/vtk/-/merge\_requests/11367](https://gitlab.kitware.com/vtk/vtk/-/merge_requests/11367)