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  3. IXRTrackingSystem

IXRTrackingSystem

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

API > API/Runtime > API/Runtime/HeadMountedDisplay

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

   
Name IXRTrackingSystem
Type class
Header File /Engine/Source/Runtime/HeadMountedDisplay/Public/IXRTrackingSystem.h
Include Path #include "IXRTrackingSystem.h"

Syntax

class IXRTrackingSystem :  
    public IModularFeature,  
    public IXRSystemIdentifier

Implements Interfaces

Derived Classes

Constants

Name Type Remarks Include Path
HMDDeviceId const int32 Device id 0 is reserved for an HMD. IXRTrackingSystem.h

Functions

Public

Name Remarks Include Path Unreal Specifiers

virtual void CalibrateExternalTrackingSource ( const FTransform& ExternalTrackingTransform
)

 Called to calibrate the offset transform between an external tracking source and the internal tracking source (e.g. mocap tracker to and HMD tracker). IXRTrackingSystem.h  

virtual EXRDeviceConnectionResult::Type ConnectRemoteXRDevice ( const FString& IpAddress,
const int32 BitRate
)

   IXRTrackingSystem.h  

uint32 CountTrackedDevices ( EXRTrackedDeviceType Type
)

 Get the count of tracked devices IXRTrackingSystem.h  

virtual void DisconnectRemoteXRDevice()

   IXRTrackingSystem.h  
Return true if the default camera implementation should query the current projection matrix at the start of the render frame and apply late update. IXRTrackingSystem.h  

virtual 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. IXRTrackingSystem.h  

bool DoesSupportPositionalTracking()

 Whether or not the system supports positional tracking (either via sensor or other means) IXRTrackingSystem.h  

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. IXRTrackingSystem.h  

virtual const TSharedPtr< const FARSupportInterface, ESPMode::ThreadSafe > GetARCompositionComponent ()

   IXRTrackingSystem.h  

virtual TSharedPtr< FARSupportInterface, ESPMode::ThreadSafe > GetARCompositionComponent ()

 Access optionsal ARCompositionComponent IXRTrackingSystem.h  

virtual FVector GetAudioListenerOffset ( int32 DeviceId
) const

 Get the offset, in device space, of the reported device (screen / eye) position to the center of the head. IXRTrackingSystem.h  

virtual FQuat GetBaseOrientation()

 Returns current base orientation of HMD as a quaternion. IXRTrackingSystem.h  

virtual FVector GetBasePosition()

 Returns current base position of HMD. IXRTrackingSystem.h  

virtual FRotator GetBaseRotation()

 Returns current base orientation of HMD as yaw-pitch-roll combination. IXRTrackingSystem.h  

bool GetCurrentInteractionProfile ( const EControllerHand Hand,
FString& InteractionProfile
)

   IXRTrackingSystem.h  

bool GetCurrentPose ( int32 DeviceId,
FQuat& OutOrientation,
FVector& OutPosition
)

 Get the current pose for a device. IXRTrackingSystem.h  

bool GetFloorToEyeTrackingTransform ( FTransform& OutFloorToEye
) const

 Computes a transform to convert from 'Floor' origin space to 'Eye' origin space. IXRTrackingSystem.h  

void GetHandTrackingState ( UObject* WorldContext,
const EXRSpaceType XRSpaceType,
const EControllerHand Hand,
FXRHandTrackingState& HandTrackingState
)

   IXRTrackingSystem.h  

virtual void GetHMDData ( UObject* WorldContext,
FXRHMDData& HMDData
)

 Platform Agnostic Query about HMD details IXRTrackingSystem.h  

virtual IHeadMountedDisplay * GetHMDDevice()

 Access HMD rendering-related features. IXRTrackingSystem.h  

virtual IOpenXRHMD * GetIOpenXRHMD()

 Get the IOpenXRHMD interface, if there is one. IXRTrackingSystem.h  

virtual IXRLoadingScreen * GetLoadingScreen()

 Access the loading screen interface associated with this tracking system, if any. IXRTrackingSystem.h  

void GetMotionControllerData ( UObject* WorldContext,
const EControllerHand Hand,
FXRMotionControllerData& MotionControllerData
)

 Platform Agnostic Query about MotionControllers details IXRTrackingSystem.h  

void GetMotionControllerState ( UObject* WorldContext,
const EXRSpaceType XRSpaceType,
const EControllerHand Hand,
const EXRControllerPoseType XRControllerPoseType,
FXRMotionControllerState& MotionControllerState
)

   IXRTrackingSystem.h  

virtual FVector2D GetPlayAreaBounds ( EHMDTrackingOrigin::Type Origin
) const

 Get the bounds of the area where the user can freely move while remaining tracked centered around the specified origin IXRTrackingSystem.h  

virtual bool GetPlayAreaRect ( FTransform& OutTransform,
FVector2D& OutRect
) const

 Get the transform and dimensions of the area where the user can freely move while remaining tracked centered around the specified origin transform IXRTrackingSystem.h  

bool GetRelativeEyePose ( int32 DeviceId,
int32 ViewIndex,
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. IXRTrackingSystem.h  

virtual TSharedPtr< class IStereoRendering, ESPMode::ThreadSafe > GetStereoRenderingDevice ()

 Access Stereo rendering device associated with this XR system. IXRTrackingSystem.h  

FString GetTrackedDevicePropertySerialNumber ( int32 DeviceId
)

 If the device id represents a tracking sensor, reports the serial number as a string if the device supports it. IXRTrackingSystem.h  

EXRTrackedDeviceType GetTrackedDeviceType ( int32 DeviceId
) const

 If the device id represents a tracking sensor, reports the device type. IXRTrackingSystem.h  

EHMDTrackingOrigin::Type GetTrackingOrigin()

 Returns current tracking origin. IXRTrackingSystem.h  

virtual bool GetTrackingOriginTransform ( TEnumAsByte< EHMDTrackingOrigin::Type > Origin,
FTransform& OutTransform
) const

 Get the transform of the specified tracking origin, if available. IXRTrackingSystem.h  

bool GetTrackingSensorProperties ( int32 DeviceId,
FQuat& OutOrientation,
FVector& OutPosition,
FXRSensorProperties& OutSensorProperties
)

 If the device id represents a tracking sensor, reports the frustum properties in game-world space of the sensor. IXRTrackingSystem.h  
Returns the system's latest known tracking-to-world transform. IXRTrackingSystem.h  

FString GetVersionString()

 Returns version string. IXRTrackingSystem.h  
This method should return the world to meters scale for the current frame. IXRTrackingSystem.h  

TSharedPtr< class IXRCamera, ESPMode::ThreadSafe > GetXRCamera ( int32 DeviceId
)

 Get the IXCamera instance for the given device. IXRTrackingSystem.h  

virtual IXRInput * GetXRInput ()

 Deprecated, and will be removed in a future release. IXRTrackingSystem.h  

int32 GetXRSystemFlags()

 Returns device specific flags. IXRTrackingSystem.h  

bool HasValidTrackingPosition()

 If the system currently has valid tracking positions. If not supported at all, returns false. IXRTrackingSystem.h  
Returns true, if head tracking is allowed. IXRTrackingSystem.h  

virtual bool IsHeadTrackingAllowedForWorld ( UWorld& World
) const

 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) IXRTrackingSystem.h  

virtual bool IsHeadTrackingEnforced ()

 Can be used to enforce tracking even when stereo rendering is disabled. IXRTrackingSystem.h  

bool IsTracking ( int32 DeviceId
)

 Check current tracking status of a device. IXRTrackingSystem.h  

virtual void OnBeginPlay ( FWorldContext& InWorldContext
)

 This method is called when playing begins. Useful to reset all runtime values stored in the plugin. IXRTrackingSystem.h  

virtual void OnBeginRendering_GameThread ( FSceneViewFamily& InViewFamily
)

   IXRTrackingSystem.h  

virtual void OnBeginRendering_GameThread ()

 Called just before rendering the current frame on the game frame. IXRTrackingSystem.h  

virtual void OnBeginRendering_RenderThread ( FRDGBuilder& GraphBuilder,
FSceneViewFamily& ViewFamily
)

   IXRTrackingSystem.h  

virtual void OnBeginRendering_RenderThread ( FRHICommandListImmediate& RHICmdList,
FSceneViewFamily& ViewFamily
)

 Called just before rendering the current frame on the render thread. IXRTrackingSystem.h  

virtual bool OnEndGameFrame ( FWorldContext& WorldContext
)

 This method is called when game frame ends (called on a game thread). IXRTrackingSystem.h  

virtual void OnEndPlay ( FWorldContext& InWorldContext
)

 This method is called when playing ends. Useful to reset all runtime values stored in the plugin. IXRTrackingSystem.h  

virtual void OnLateUpdateApplied_RenderThread ( FRHICommandListImmediate& RHICmdList,
const FTransform& NewRelativeTransform
)

 Called just after the late update on the render thread passing back the current relative transform. IXRTrackingSystem.h  

virtual void OnLateUpdateApplied_RenderThread ( FRDGBuilder& GraphBuilder,
const FTransform& NewRelativeTransform
)

   IXRTrackingSystem.h  

virtual bool OnStartGameFrame ( FWorldContext& WorldContext
)

 This method is called when new game frame begins (called on a game thread). IXRTrackingSystem.h  

virtual void RebaseObjectOrientationAndPosition ( FVector& Position,
FQuat& Orientation
) const

 Temporary method until Morpheus controller code has been refactored. IXRTrackingSystem.h  

virtual void ResetOrientation ( float Yaw
)

 Resets orientation by setting roll and pitch to 0, assuming that current yaw is forward direction. IXRTrackingSystem.h  

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). IXRTrackingSystem.h  

virtual void ResetPosition()

 Resets position, assuming current position as a 'zero-point'. IXRTrackingSystem.h  

virtual void SetBaseOrientation ( const FQuat& BaseOrient
)

 Sets base orientation, assuming that this is forward direction. Position is not changed. IXRTrackingSystem.h  

virtual void SetBasePosition ( const FVector& BasePosition
)

 Sets base position of the HMD. IXRTrackingSystem.h  

virtual void SetBaseRotation ( const FRotator& BaseRot
)

 Sets base orientation by setting yaw, pitch, roll, assuming that this is forward direction. IXRTrackingSystem.h  

virtual void SetHeadTrackingEnforced ( bool bEnabled
)

 Can be used to enforce tracking even when stereo rendering is disabled. IXRTrackingSystem.h  

void SetTrackingOrigin ( EHMDTrackingOrigin::Type NewOrigin
)

 Sets tracking origin (either 'eye'-level or 'floor'-level). IXRTrackingSystem.h  

virtual void UpdateExternalTrackingPosition ( const FTransform& ExternalTrackingTransform
)

 Called after calibration to attempt to pull the internal tracker (e.g. HMD tracking) in line with the external tracker (e.g. mocap tracker). IXRTrackingSystem.h  

void UpdateTrackingToWorldTransform ( const FTransform& TrackingToWorldOverride
)

 Refreshes the system's known tracking-to-world transform. IXRTrackingSystem.h  

Static

Name Remarks Include Path Unreal Specifiers

static FName GetModularFeatureName()

   IXRTrackingSystem.h  

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