Resolved Manual OpenXR Load with Unity Input System not working

I have a 2020.3 project and I have Initialize XR on Startup in Project Settings set to false because I want to manually start VR. Then, in my input monobehaviour Awake I write:

Code (CSharp):

1. XRGeneralSettings.Instance.Manager.InitializeLoaderSync();
2. XRGeneralSettings.Instance.Manager.StartSubsystems();

Then I call my input.actions.Enable();

If I have my Index headset turned off, I have to press Play in the editor TWICE for SteamVR to turn on. But input isn't recognized in either play.

If I have Initialize XR on Startup set to true, then SteamVR handles my input properly (but after running Play twice as well).

What gives?

Using Unity 2020.3.0f1
SteamVR beta 1.16.10
OpenXR Plugin 1.0.2
Input System 1.0.2

 

The problem was that there was a warning I wasn't seeing:
"XR Management has already initialized an active loader in this scene.Please make sure to stop all subsystems and deinitialize the active loader before initializing a new one."

And this did not allow me to use VR. This shouldn't be a warning, it should be an error as everything continues on as active but without functionality.

The fix was to StopSubsystems and Deinitialize the active loader BEFORE initializing it. This should be an addendum to everyone else who Googled a fix for manually initializing OpenXR:

Code (CSharp):

1. public void Awake(){
2.         //fix
3.         if( XRGeneralSettings.Instance.Manager.activeLoader != null ){
4.             XRGeneralSettings.Instance.Manager.StopSubsystems();
5.             XRGeneralSettings.Instance.Manager.DeinitializeLoader();
6.         }
7.         XRGeneralSettings.Instance.Manager.InitializeLoaderSync();
8.         XRGeneralSettings.Instance.Manager.StartSubsystems();
9.  
10.         var actions = new InputActions();
11.         actions.Enable();
12.  
13.         actions.vrControls.leftAnalogPos.performed += ctx => Debug.LogError( ctx.ReadValue<Vector2>() );
14.     }

Thanks.

 

Think there is something more going on here, because i'm having the same issue the OG poster is describing.

1. If you uncheck Initialize XR on Startup, enter play mode then start the loader manually in code
2. Stop Play mode
3. Start play mode again - it automatically loads the first loader in the list.
4. Re-enable Initialize XR on Startup and enter play mode
5. Immediately receive the following error - clearly it's trying to load it twice "automatically"

XR Management has already initialized an active loader in this scene.Please make sure to stop all subsystems and deinitialize the active loader before initializing a new one.
UnityEngine.XR.Management.XRGeneralSettings:AttemptInitializeXRSDKOnLoad () (at Library/PackageCache/com.unity.xr.management@4.0.1/Runtime/XRGeneralSettings.cs:148)

It's almost as if the loader from the previous play mode is still "active". Which sounds strange, but nothing else makes sense.

Definitely a XR Plugin Management issue. Not OpenXR, because I'm only testing manually loading of the Oculus plugin right now.

Unity 2020.3
XR Plugin Management 4.0.1
Edit: Tested in 2019.4.20 and has the same behaviour.

 

Upon further testing, this will happen if you stopped your play session in the editor without cleaning up the Manually loaded XR SubSystems.

I cleaned up the Subsystems in OnApplicationQuit, and upon the next play session the "previous loader" is no longer there causing the trouble.

 

THANK YOU. I wasn't even initiatizing XR in script, but since upgrading to Unity 2019.4 I was suddenly only able to run VR in playmode once. This fixed me.

 

Cheerfully still broken in November 2022 and thank you SO much for the fix!

 

Still a problem on 2021.3.14f, any updates?

 

Still a problem in 2021.3.31. I have 2 separate unity projects, one where this occurs and one where it doesn't, trying to track down the difference but no luck and can't seem to figure out why one is initializing a loader before my code tells it to with the "Initialize XR on Startup" unchecked...