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> Unreal Engine API Reference > Runtime > HeadMountedDisplay > FXRTrackingSystemBase

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FXRTrackingSystemBase

Base utility class for implementations of the [IXRTrackingSystem](API\Runtime\HeadMountedDisplay\IXRTrackingSystem) interface Contains helpers and default implementation of most abstract methods, so final implementations only need to override features that they support.

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Inheritance Hierarchy

IModularFeature

IXRSystemIdentifier

IXRTrackingSystem

FXRTrackingSystemBase

	FHeadMountedDisplayBase
	FXRTrackingProxy

References

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

Syntax

class FXRTrackingSystemBase : public IXRTrackingSystem

Remarks

Base utility class for implementations of the IXRTrackingSystem interface Contains helpers and default implementation of most abstract methods, so final implementations only need to override features that they support.

Variables

	Name	Description
FTransform	CachedTrackingToWorld
FTransform	CalibratedOffset	If the tracker is trying to lock itself to an external tracking source for drift control, this stores the calibrated offset between the external tracking system and the internal tracking system (e.g. a location from a mocap system tracker to the HMD's internal IMU).
IXRLoadingScree...	LoadingScreen
TSharedPtr< cla...	XRCamera

Constructors

	Name	Description
	FXRTrackingSystemBase ( IARSystemSupport* InARImplemen... )

Destructors

	Name	Description
	~FXRTrackingSystemBase()

Functions

	Name	Description
FTransform	ComputeTrackingToWorldTransform ( FWorldContext& WorldContext )
IXRLoadingSc...	CreateLoadingScreen()	Override this method if you need to customize the IXRLoadingScreen implementation.
TSharedPtr< ...	GetARCompositionComponent()
const TShare...	GetARCompositionComponent()
void	OnTrackingOriginChanged()	Meant to be called by sub-classes whenever the tracking origin is altered.
FTransform	RefreshTrackingToWorldTransform ( FWorldContext& WorldContext )	Computes the project's tracking-to-world transform based off how the user has set up their camera system (assumes the camera is parented to the XR origin, and in turn uses that transform).

Overridden from IXRTrackingSystem

	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... )
uint32	CountTrackedDevices ( EXRTrackedDeviceType Type )	Get the count of tracked devices.
bool	DoesSupportPositionalTracking()	Whether or not the system supports positional tracking (either via sensor or other means).
bool	GetFloorToEyeTrackingTransform ( FTransform& OutFloorToEye )	Returns a transform for converting from 'Floor' origin space to 'Eye' origin space.
IXRLoadingSc...	GetLoadingScreen()	Access the loading screen interface associated with this tracking system, if any.
void	GetMotionControllerData ( UObject* WorldContext, const EControllerHand Hand, FXRMotionControllerData& MotionCon... )	Platform Agnostic Query about MotionControllers details
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.
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. The default implementation always reports 'eye'-level tracking.
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.
TSharedPtr< ...	GetXRCamera ( int32 DeviceId )	Get the IXCamera instance for the given device.
bool	HasValidTrackingPosition()	If the system currently has valid tracking positions.
bool	IsTracking ( int32 DeviceId )	Check current tracking status of a device.
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.

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