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> Unreal Engine API Reference > Runtime > HeadMountedDisplay > IXRTrackingSystem

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IXRTrackingSystem

Main access point to an XR tracking system. Use it to enumerate devices and query their poses.

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Linux

Inheritance Hierarchy

IModularFeature

IXRSystemIdentifier

IXRTrackingSystem

FXRTrackingSystemBase

	FHeadMountedDisplayBase
	FXRTrackingProxy

References

Module	HeadMountedDisplay
Header	/Engine/Source/Runtime/HeadMountedDisplay/Public/IXRTrackingSystem.h
Include	#include "IXRTrackingSystem.h"

Syntax

class IXRTrackingSystem :
public IModularFeature,
public IXRSystemIdentifier

Remarks

Main access point to an XR tracking system. Use it to enumerate devices and query their poses.

Functions

	Name	Description
void	CalibrateExternalTrackingSource ( const FTransform& ExternalTracking... )	Called to calibrate the offset transform between an external tracking source and the internal tracking source (e.g. mocap tracker to and HMD tracker).
bool	ConfigureGestures ( const FXRGestureConfig& GestureCon... )
EXRDeviceCon...	ConnectRemoteXRDevice ( const FString& IpAddress, const int32 BitRate )
uint32	CountTrackedDevices ( EXRTrackedDeviceType Type )	Get the count of tracked devices
void	DisconnectRemoteXRDevice()
bool	DoesSupportLateUpdate()	Return true if the default camera implementation should query the current pose at the start of the render frame and apply late update.
bool	DoesSupportPositionalTracking()	Whether or not the system supports positional tracking (either via sensor or other means)
bool	EnumerateTrackedDevices ( TArray< int32 >& OutDevices, EXRTrackedDeviceType Type )	Reports all devices currently available to the system, optionally limiting the result to a given class of devices.
FVector	GetAudioListenerOffset ( int32 DeviceId )	Get the offset, in device space, of the reported device (screen / eye) position to the center of the head.
FQuat	GetBaseOrientation()	Returns current base orientation of HMD as a quaternion.
FVector	GetBasePosition()	Returns current base position of HMD.
FRotator	GetBaseRotation()	Returns current base orientation of HMD as yaw-pitch-roll combination.
bool	GetCurrentPose ( int32 DeviceId, FQuat& OutOrientation, FVector& OutPosition )	Get the current pose for a device.
bool	GetFloorToEyeTrackingTransform ( FTransform& OutFloorToEye )	Computes a transform to convert from 'Floor' origin space to 'Eye' origin space.
void	GetHMDData ( UObject* WorldContext, FXRHMDData& HMDData )	Platform Agnostic Query about HMD details
IHeadMounted...	GetHMDDevice()	Access HMD rendering-related features.
IXRLoadingSc...	GetLoadingScreen()	Access the loading screen interface associated with this tracking system, if any.
FName	GetModularFeatureName()
void	GetMotionControllerData ( UObject* WorldContext, const EControllerHand Hand, FXRMotionControllerData& MotionCon... )	Platform Agnostic Query about MotionControllers details
FVector2D	GetPlayAreaBounds ( EHMDTrackingOrigin::Type Origin )	Get the bounds of the area where the user can freely move while remaining tracked centered around the specified origin
bool	GetRelativeEyePose ( int32 DeviceId, EStereoscopicPass Eye, FQuat& OutOrientation, FVector& OutPosition )	If the device id represents a head mounted display, fetches the relative position of the given eye relative to the eye.
TSharedPtr< ...	GetStereoRenderingDevice()	Access Stereo rendering device associated with this XR system.
FString	GetTrackedDevicePropertySerialNumber ( int32 DeviceId )	If the device id represents a tracking sensor, reports the serial number as a string if the device supports it.
EXRTrackedDe...	GetTrackedDeviceType ( int32 DeviceId )	If the device id represents a tracking sensor, reports the device type.
EHMDTracking...	GetTrackingOrigin()	Returns current tracking origin.
bool	GetTrackingSensorProperties ( int32 DeviceId, FQuat& OutOrientation, FVector& OutPosition, FXRSensorProperties& OutSensorProp... )	If the device id represents a tracking sensor, reports the frustum properties in game-world space of the sensor.
FTransform	GetTrackingToWorldTransform()	Returns the system's latest known tracking-to-world transform.
FString	GetVersionString()	Returns version string.
float	GetWorldToMetersScale()	This method should return the world to meters scale for the current frame.
TSharedPtr< ...	GetXRCamera ( int32 DeviceId )	Get the IXCamera instance for the given device.
IXRInput ...	GetXRInput()	Access optional HMD input override interface.
int32	GetXRSystemFlags()	Returns device specific flags.
bool	HasValidTrackingPosition()	If the system currently has valid tracking positions. If not supported at all, returns false.
bool	IsHeadTrackingAllowed()	Returns true, if head tracking is allowed.
bool	IsHeadTrackingAllowedForWorld ( UWorld& World )	Same as IsHeadTrackingAllowed, but returns false if the World is not using VR (such as with the non-VR PIE instances when using VR Preview)
bool	IsHeadTrackingEnforced()	Can be used to enforce tracking even when stereo rendering is disabled.
bool	IsTracking ( int32 DeviceId )	Check current tracking status of a device.
bool	LateLatchingEnabled()	Return true if platform and HMD support late latching Please override to enable it.
void	OnBeginPlay ( FWorldContext& InWorldContext )	This method is called when playing begins. Useful to reset all runtime values stored in the plugin.
void	OnBeginRendering_GameThread()	Called just before rendering the current frame on the game frame.
void	OnBeginRendering_RenderThread ( FRHICommandListImmediate& RHICmdLi..., FSceneViewFamily& ViewFamily )	Called just before rendering the current frame on the render thread.
bool	OnEndGameFrame ( FWorldContext& WorldContext )	This method is called when game frame ends (called on a game thread).
void	OnEndPlay ( FWorldContext& InWorldContext )	This method is called when playing ends. Useful to reset all runtime values stored in the plugin.
void	OnLateUpdateApplied_RenderThread ( FRHICommandListImmediate& RHICmdLi..., const FTransform& NewRelativeTrans... )	Called just after the late update on the render thread passing back the current relative transform.
bool	OnStartGameFrame ( FWorldContext& WorldContext )	This method is called when new game frame begins (called on a game thread).
void	RebaseObjectOrientationAndPosition ( FVector& Position, FQuat& Orientation )	Temporary method until Morpheus controller code has been refactored.
void	ResetOrientation ( float Yaw )	Resets orientation by setting roll and pitch to 0, assuming that current yaw is forward direction.
void	ResetOrientationAndPosition ( float Yaw )	Resets orientation by setting roll and pitch to 0, assuming that current yaw is forward direction and assuming current position as a 'zero-point' (for positional tracking).
void	ResetPosition()	Resets position, assuming current position as a 'zero-point'.
void	SetBaseOrientation ( const FQuat& BaseOrient )	Sets base orientation, assuming that this is forward direction. Position is not changed.
void	SetBasePosition ( const FVector& BasePosition )	Sets base position of the HMD.
void	SetBaseRotation ( const FRotator& BaseRot )	Sets base orientation by setting yaw, pitch, roll, assuming that this is forward direction.
void	SetHeadTrackingEnforced ( bool bEnabled )	Can be used to enforce tracking even when stereo rendering is disabled.
void	SetTrackingOrigin ( EHMDTrackingOrigin::Type NewOrigin )	Sets tracking origin (either 'eye'-level or 'floor'-level).
void	UpdateExternalTrackingPosition ( const FTransform& ExternalTracking... )	Called after calibration to attempt to pull the internal tracker (e.g. HMD tracking) in line with the external tracker (e.g. mocap tracker).
void	UpdateTrackingToWorldTransform ( const FTransform& TrackingToWorldO... )	Refreshes the system's known tracking-to-world transform.

Constants

Name	Description
HMDDeviceId	Device id 0 is reserved for an HMD.

Deprecated Functions

		Name	Description
	void	RefreshPoses()	This functionality is no longer supported.

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