How to use OpenGL 2.0 in Unity?

Question

I want to develop a game in Unity, just a small scale simple game without heavy computation or complicated features, one that does not use a lot of RAM (2-3 GB). I want players with "outdated devices" (device that does not support OpenGL 3.0 or higher) to still be able to play my game, because apparently these outdated devices are still widely used, especially in poorer regions, due to their cheap price. Forcing OpenGL 3.0 would prevent these devices from playing my game despite my game using features that can be implemented in OpenGL 2.0, so it does not make sense to use OpenGL 3.0 in the first place.

I've tried to find information regarding the OpenGL version used by Unity, however I have only found https://docs.unity3d.com/Manual/OpenGLCoreDetails.html. In that article it was said

This scales from OpenGL 3.2 to OpenGL 4.5 depending on the OpenGL driver support.

I even tried changing the documentation version to the oldest one possible (2017.1) and it still said the same exact sentence.

Does this mean OpenGL older than 3.2 is not supported by Unity? Or is there any workaround to this?

Answer 1

According to this post on Unity Forums website, OpenGL 2 support was dropped since Unity 5.5:

...since Unity 5.5, OpenGL core profile 3.2 is the minimum supported version.

And OpenGL ES 2 support was dropped in Unity 2022:

Unity 2022 will offer no GLES2 support for Android and will instead raise an error on importing an older project.

So, basically, you'll need to use an Editor version pre 5.5 (5.4 and older). You can still download previous Editor versions from the archive: here.

Answer 2

This article shows how to enable OpenGL ES 2.0 support on Android, by going to Edit > Project Settings > Player > Android > Other Settings, disabling "Auto Graphics API", then adding the version you want manually.

I don't have an OpenGL ES 2.0 smartphone, so I haven't confirmed this operation myself.