What are the differences between Oculus OpenXR and Epic OpenXR ?

[motorsep]

There are two option for OpenXR API in UE's Project Settings. One is Oculus OpenXR and another one is Epic OpenXR.

I use VRE plugin and if I use Oculus OpenXR, I completely lose hand tracking functionality provided by VRE (which is amazing btw). If I use Epic OpenXR, I get everything I can wish for, except for some reason game's colors are washed out and who knows what else I miss out on (whatever special sauce Oculus OpenXR has over Epic's OpenXR).

So, I am wondering what do I lose by going with Epic OpenXR over Oculus OpenXR ?

[Starkium]

not sure why, but that sounds like it would be the tone mapper. 

[motorsep]

I mostly wonder about performance differences.

[JayLu2000 · Accepted solution]

Hey [motorsep](https://github.com/motorsep),

short version of answer: this is for devs who want platform independent features (OpenXR supported features) only and this is not for performance. Once enabled, you, most likely, will get a feature subset of the default option.

long version:

I would suggest not to use it unless you are familiar with OpenXR and you could check OpenXR extensions to figure out what features you are getting. What it does is, like the tooltip showing: IF you enable Epic's openxr plugin and enable this option, then, you will get functionalities from openxr plugin and other openxr extensions supported by Quest runtime AND ovrplugin dll won't be used. On the other side, you will lose some features provided by ovrplugin.

And again, like what the tooltip hinted, there's a WIP work to improve this to "to improve modularity" and once that's done, it will be much easier to use (hopefully). 

And I don't think it will get you better performance.

thanks!

[JayLu2000]

PS: talking about performance, I would highly suggest to give our latest perf improvement a try: https://developer.oculus.com/documentation/unreal/po-fork-engine-perf/

Especially, Occlusion wise, there used to be a big issue there and we just fixed it.
thanks!

[motorsep]

That's an awesome and useful info, thanks!