Tracker Tutorial: Update Tracker

Tracker.cpp

vr::HmdMatrix34_t ATracker::UpdateTracker(int id)
{
	//Get Tracker Pose
	vr::VRControllerState_t *state = new vr::VRControllerState_t();
	vr::TrackedDevicePose_t *pose = new vr::TrackedDevicePose_t();
	vrSystem->GetControllerStateWithPose(vr::ETrackingUniverseOrigin::TrackingUniverseStanding, id, state, sizeof(vr::VRControllerState_t), pose);
	//Get Pose Position
	vr::HmdMatrix34_t posMat = pose->mDeviceToAbsoluteTracking;
  // Update tracker only if we have decided which tracker to use
	if (trackerID != -1)
	{

		//Build Quaternion From Matrix
		float w = FGenericPlatformMath::Sqrt(1.0 + posMat.m[0][0] + posMat.m[1][1] + posMat.m[2][2]) / 2.0;
		float w4 = (4.0 * w);
		float x = (posMat.m[2][1] - posMat.m[1][2]) / w4;
		float y = (posMat.m[0][2] - posMat.m[2][0]) / w4;
		float z = (posMat.m[1][0] - posMat.m[0][1]) / w4;

		// Postion and Rotate Actor
		
		sceneComponent->SetWorldLocationAndRotationNoPhysics(
			FVector(-posMat.m[2][3] * 100, posMat.m[0][3] * 100, posMat.m[1][3] * 100),
			FQuat(z, -x, -y, w).Rotator());
	}
	
	return posMat;
}