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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

Inheritance Hierarchy

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

  Type Name Description
Public function 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).
Public function Virtual EXRDeviceConnectionResult::Type

ConnectRemoteXRDevice ( const FString& IpAddress,
const int32 BitRate
)

  
Public function uint32

CountTrackedDevices ( EXRTrackedDeviceType Type
)

 Get the count of tracked devices
Public function Virtual void  
Public function Virtual Const bool Return true if the default camera implementation should query the current projection matrix at the start of the render frame and apply late update.
Public function Virtual Const bool Return true if the default camera implementation should query the current pose at the start of the render frame and apply late update.
Public function Const bool Whether or not the system supports positional tracking (either via sensor or other means)
Public function 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.
Public function Virtual TSharedPtr< FARSupportInterface, ESPMode::ThreadSafe > Access optionsal ARCompositionComponent
Public function Virtual Const const TSharedPtr< const FARSupportInterface, ESPMode::ThreadSafe >  
Public function Virtual Const FVector

GetAudioListenerOffset ( int32 DeviceId
)

 Get the offset, in device space, of the reported device (screen / eye) position to the center of the head.
Public function Virtual Const FQuat Returns current base orientation of HMD as a quaternion.
Public function Virtual Const FVector Returns current base position of HMD.
Public function Virtual Const FRotator Returns current base orientation of HMD as yaw-pitch-roll combination.
Public function bool

GetCurrentInteractionProfile ( const EControllerHand Hand,
FString& InteractionProfile
)

  
Public function bool

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

 Get the current pose for a device.
Public function Const bool

GetFloorToEyeTrackingTransform ( FTransform& OutFloorToEye
)

 Computes a transform to convert from 'Floor' origin space to 'Eye' origin space.
Public function Virtual void

GetHMDData ( UObject* WorldContext,
FXRHMDData& HMDData
)

 Platform Agnostic Query about HMD details
Public function Virtual IHeadMountedDisplay * Access HMD rendering-related features.
Public function Virtual IXRLoadingScreen * Access the loading screen interface associated with this tracking system, if any.
Public function Static FName  
Public function void

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

 Platform Agnostic Query about MotionControllers details
Public function Virtual Const FVector2D Get the bounds of the area where the user can freely move while remaining tracked centered around the specified origin
Public function Virtual Const bool

GetPlayAreaRect ( FTransform& OutTransform,
FVector2D& OutRect
)

 Get the transform and dimensions of the area where the user can freely move while remaining tracked centered around the specified origin transform
Public function 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.
Public function Virtual TSharedPtr< class IStereoRendering, ESPMode::ThreadSafe > Access Stereo rendering device associated with this XR system.
Public function FString If the device id represents a tracking sensor, reports the serial number as a string if the device supports it.
Public function Const EXRTrackedDeviceType

GetTrackedDeviceType ( int32 DeviceId
)

 If the device id represents a tracking sensor, reports the device type.
Public function Const EHMDTrackingOrigin::Type Returns current tracking origin.
Public function Virtual Const bool

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

 Get the transform of the specified tracking origin, if available.
Public function 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.
Public function Const FTransform Returns the system's latest known tracking-to-world transform.
Public function Const FString Returns version string.
Public function Const float This method should return the world to meters scale for the current frame.
Public function TSharedPtr< class IXRCamera, ESPMode::ThreadSafe >

GetXRCamera ( int32 DeviceId
)

 Get the IXCamera instance for the given device.
Public function Virtual IXRInput * Access optional HMD input override interface.
Public function Const int32 Returns device specific flags.
Public function bool If the system currently has valid tracking positions. If not supported at all, returns false.
Public function Const bool Returns true, if head tracking is allowed.
Public function Virtual Const bool 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)
Public function Virtual Const bool Can be used to enforce tracking even when stereo rendering is disabled.
Public function bool

IsTracking ( int32 DeviceId
)

 Check current tracking status of a device.
Public function Virtual void

OnBeginPlay ( FWorldContext& InWorldContext
)

 This method is called when playing begins. Useful to reset all runtime values stored in the plugin.
Public function Virtual void Called just before rendering the current frame on the game frame.
Public function Virtual void Called just before rendering the current frame on the render thread.
Public function Virtual bool

OnEndGameFrame ( FWorldContext& WorldContext
)

 This method is called when game frame ends (called on a game thread).
Public function Virtual void

OnEndPlay ( FWorldContext& InWorldContext
)

 This method is called when playing ends. Useful to reset all runtime values stored in the plugin.
Public function 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.
Public function Virtual bool

OnStartGameFrame ( FWorldContext& WorldContext
)

 This method is called when new game frame begins (called on a game thread).
Public function Virtual Const void

RebaseObjectOrientationAndPosition ( FVector& Position,
FQuat& Orientation
)

 Temporary method until Morpheus controller code has been refactored.
Public function Virtual void

ResetOrientation ( float Yaw
)

 Resets orientation by setting roll and pitch to 0, assuming that current yaw is forward direction.
Public function void 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).
Public function Virtual void Resets position, assuming current position as a 'zero-point'.
Public function Virtual void

SetBaseOrientation ( const FQuat& BaseOrient
)

 Sets base orientation, assuming that this is forward direction. Position is not changed.
Public function Virtual void

SetBasePosition ( const FVector& BasePosition
)

 Sets base position of the HMD.
Public function Virtual void

SetBaseRotation ( const FRotator& BaseRot
)

 Sets base orientation by setting yaw, pitch, roll, assuming that this is forward direction.
Public function Virtual void

SetHeadTrackingEnforced ( bool bEnabled
)

 Can be used to enforce tracking even when stereo rendering is disabled.
Public function void Sets tracking origin (either 'eye'-level or 'floor'-level).
Public function 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).
Public function void

UpdateTrackingToWorldTransform ( const FTransform& TrackingToWorldOverride
)

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

Constants

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

Deprecated Functions

  Type Name Description
Public function Virtual bool

ConfigureGestures ( const FXRGestureConfig& GestureConfig
)

 The only implementation for this function was removed many UE releases ago.
Public function Virtual void This functionality is no longer supported.

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