[VBS & PC VR ] How to identify lost tracking and tracking result status on OpenVR

[Vivi Wu]

To identify if the device is lost tracking, the developer needs to use OpenVR API to get the device status. 
Also if you'd like to know whether your controller / wrist tracker is in 6Dof or 3Dof status, please follow the guidelines below and refer to OpenVR GitHub for more information. 

Required:

• VIVE Business Streaming version : 1.10.5 or later.
• Focus 3 – FOTA version : 5.0.999.676 or later
   

Check OpenVR API to get status

IVRSystem :

• IVRSystem::GetDeviceToAbsoluteTrackingPose
• IVRSystem::GetControllerStateWithPose

IVRCompositor :

• IVRCompositor::GetLatestPoses (similar with WaitGetPoses)
   

Both API can get TrackedDevicePose_t of devices with parameter-“ETrackingResult”, which is the tracking status of device.

• 6Dof = TrackingResult_Running_OK
• 3Dof = TrackingResult_Fallback_RotationOnly

All of the APIs can get TrackedDevicePose_t which includes several parameters to identify the device tracking status.

• bPoseIsValid
• bDeviceIsConnected
• eTrackingResult
  • TrackingResult_Running_OK: 6DoF
  • TrackingResult_Fallback_RotationOnly: 3DoF

Only the “bPoseIsValid” is true, “bDeviceIsConnected” is true and “eTrackingResult” is TrackingResult_Running_OK or TrackingResult_Fallback_RotationOnly means tracked. Otherwise, the device status should be lost tracking.

 

The index of each device:
To use the APIs, please use below device index for vr::TrackedDeviceIndex_t or pose array to get target device pose data.

index	device
0	HMD
1	Right controller
2	Left controller
3	Right wrist tracker
4	Left wrist tracker

To access the target device and retrieve its status, please generate a large enough array and call the appropriate API. Use the index specified in the above table to obtain the status of the target device.

Sample code:

Sample 1:

vr::IVRSystem * pvr = vr::VR_Init(&eError, vr::VRApplication_Utility); TrackedDevicePose_t result[5]; pvr->GetDeviceToAbsoluteTrackingPose(vr::TrackingUniverseStanding, 0, &result, 5); result[1].eTrackingResult; // right controller tracking result result[2].eTrackingResult; // left controller tracking result result[3].eTrackingResult; // right wrist tracker tracking result result[4].eTrackingResult; // left wrist tracker tracking result

Sample 2:

TrackedDevicePose_t result[5]; Vr::VRCompositor()->GetLatestPoses(result, 5, NULL, 0); result[0].eTrackingResult; // HMD tracking result result[1].eTrackingResult; // right controller tracking result result[2].eTrackingResult; // left controller tracking result result[3].eTrackingResult; // right wrist tracker tracking result result[4].eTrackingResult; // left wrist tracker tracking result