Tracking loss of 6Dof on WMR and other headsets.

• Does the UnityEngine.XR API have a way to track loss of 6-dof ( six degrees of freedom ) on an HMD?
• If not, is there a Windows Mixed Reality ( WMR ) specific way to listen for the 6-dof loss event?

The closest thing I could find was:

Code (CSharp):

1.  
2.             InputTracking.GetNodeStates(nodeStates);
3.             foreach( XRNodeState ns in nodeStates )
4.             {
5.                 if( ns.nodeType == XRNode.Head )
6.                 {
7.                     IsSixDofActive = ns.tracked;
8.                 }
9.             }
10.  

However this returns whether all tracking ( position + orientation ) is active. I'm not looking for a way to detect 6-dof by processing position data and guesstimating, I need the event raised by the HMD.

 

Thanks joejo, this is what i'm looking for! However the WorldManager seems to only return the 'Unavailable' state.

I've tried two approaches:

Code (CSharp):

1.  
2. switch( WorldManager.state )
3.         {
4.  
5. case PositionalLocatorState.Active:
6. {
7.       IsSixDofActive = true;
8.       break;
9. }
10.  
11.             case PositionalLocatorState.Activating:
12.             case PositionalLocatorState.Inhibited:
13.             case PositionalLocatorState.OrientationOnly:
14.             case PositionalLocatorState.Unavailable:
15.             default:
16.             {
17.                 IsSixDofActive = false;
18.                 break;
19.             }
20. }

Code (CSharp):

1. void Start()
2.     {
3.         IsSixDofActive = false;
4.  
5.         WorldManager.OnPositionalLocatorStateChanged += OnSixDofStateChange;
6.     }
7.  
8. void OnSixDofStateChange(PositionalLocatorState PrevState, PositionalLocatorState State)
9.     {
10.         switch( State )
11.         {
12.             case PositionalLocatorState.Active:
13.             {
14.                 IsSixDofActive = true;
15.                 break;
16.             }
17.  
18.             default:
19.             {
20.                 IsSixDofActive = false;
21.                 break;
22.             }
23.         }
24.     }

Do I need to retrieve a WorldManager instance specific to my Windows Mixed Reality headset? Or it is a player XR API setup issue?

 

• I'm running a 'Samsung Windows Mixed Reality 800ZAA' headset.
• My XR player settings has only the 'OpenVR' api setup.
• Unity Version 2019.2.17f1
• Windows 10, v1909

Here's the script i'm running:

Code (CSharp):

1.  
2.     public bool IsSixDofActive = false;
3.     public PositionalLocatorState SixDofState = PositionalLocatorState.Unavailable;
4.  
5.     void Start()
6.     {
7.         WorldManager.OnPositionalLocatorStateChanged += OnSixDofStateChange;
8.     }
9.  
10.     void Update()
11.     {
12.         var prevSixDofState = SixDofState;
13.         SixDofState = WorldManager.state;
14.         if( SixDofState != prevSixDofState )
15.         {
16.             Debug.Log("6Dof polled: " + SixDofState);
17.             switch( SixDofState )
18.             {
19.                 case PositionalLocatorState.Active:
20.                 {
21.                     IsSixDofActive = true;
22.                     break;
23.                 }
24.  
25.                 case PositionalLocatorState.Activating:
26.                 case PositionalLocatorState.Inhibited:
27.                 case PositionalLocatorState.OrientationOnly:
28.                 case PositionalLocatorState.Unavailable:
29.                 default:
30.                 {
31.                     IsSixDofActive = false;
32.                     break;
33.                 }
34.             }
35.         }
36.     }
37.  
38.     void OnSixDofStateChange(PositionalLocatorState PrevState, PositionalLocatorState State)
39.     {
40.         Debug.Log("6Dof change: " + PrevState + " > " + State);
41.         switch( State )
42.         {
43.             case PositionalLocatorState.Active:
44.             {
45.                 IsSixDofActive = true;
46.                 break;
47.             }
48.  
49.             default:
50.             {
51.                 IsSixDofActive = false;
52.                 break;
53.             }
54.         }
55.     }

I'm not receiving the 'OnSixDofStateChange' event, and the polling always returns 'Unavailable'

 

Ah i see, thanks so much for the quick replies! Is there anything I could do that is WMR specific? Does Unity have any direct interface with the WMR api like Unreal?