UGoogleARCoreFrameFunctionLibrary

#include <GoogleARCoreFunctionLibrary.h>

A function library that provides static/Blueprint functions associated with most recent GoogleARCore tracking frame.

Summary

Inheritance

Inherits from: UBlueprintFunctionLibrary

Public static functions
`ARCoreLineTrace(UObject *WorldContextObject, const FVector2D & ScreenPosition, TSet< EGoogleARCoreLineTraceChannel > TraceChannels, TArray< FARTraceResult > & OutHitResults)`	`bool` Traces a ray from the user's device in the direction of the given location in the camera view.
`ARCoreLineTraceRay(UObject *WorldContextObject, const FVector & Start, const FVector & End, TSet< EGoogleARCoreLineTraceChannel > TraceChannels, TArray< FARTraceResult > & OutHitResults)`	`bool` Traces a ray along the given line.
`AcquireCameraImage(UGoogleARCoreCameraImage *& OutLatestCameraImage)`	`EGoogleARCoreFunctionStatus` Acquire a CPU-accessible camera image.
`AcquirePointCloud(UGoogleARCorePointCloud *& OutLatestPointCloud)`	`EGoogleARCoreFunctionStatus` Acquires latest point cloud.
`GetCameraImageIntrinsics(UGoogleARCoreCameraIntrinsics *& OutCameraIntrinsics)`	`EGoogleARCoreFunctionStatus` Get the camera intrinsics for the camera image (CPU image).
`GetCameraTexture()`	`UTexture *` Get the pass-through camera texture that GoogleARCore plugin will use to render the passthrough camera background.
`GetCameraTextureIntrinsics(UGoogleARCoreCameraIntrinsics *& OutCameraIntrinsics)`	`EGoogleARCoreFunctionStatus` Get the camera intrinsics for the camera texture (GPU image).
`GetLightEstimation(FGoogleARCoreLightEstimate & OutLightEstimate)`	`void` Gets the latest light estimation.
`GetPointCloud(UGoogleARCorePointCloud *& OutLatestPointCloud)`	`EGoogleARCoreFunctionStatus` Gets the latest point cloud that will be only available for this frame.
`GetPose(FTransform & OutPose)`	`void` Gets the latest tracking pose of the ARCore device in Unreal AR Tracking Space.
`GetTrackingFailureReason()`	`EGoogleARCoreTrackingFailureReason` Returns the reason when UARBlueprintLibrary::GetTrackingQuality() returns NotTracking, or UGoogleARCoreFrameFunctionLibrary::GetTrackingState returns Paused.
`GetTrackingState()`	`EGoogleARCoreTrackingState` Returns the current ARCore session status.
`GetUpdatedARPins(TArray< UARPin * > & OutAnchorList)`	`void` Gets a list of UARPin objects that were changed in this frame.
`GetUpdatedAugmentedFaces(TArray< UGoogleARCoreAugmentedFace * > & OutFaceList)`	`void` Gets a list of UGoogleARCoreAugmentedFace objects that were changed in this frame.
`GetUpdatedAugmentedImages(TArray< UGoogleARCoreAugmentedImage * > & OutImageList)`	`void` Gets a list of UGoogleARCoreAugmentedImage objects that were changed in this frame.
`GetUpdatedPlanes(TArray< UARPlaneGeometry * > & OutPlaneList)`	`void` Gets a list of UARPlaneGeometry objects that were changed in this frame.
`GetUpdatedTrackable(TArray< T * > & OutTrackableList)`	`void` Template function to get the updated trackables in this frame a given trackable type.
`GetUpdatedTrackablePoints(TArray< UARTrackedPoint * > & OutTrackablePointList)`	`void` Gets a list of UARTrackedPoint objects that were changed in this frame.
`TransformARCoordinates2D(EGoogleARCoreCoordinates2DType InputCoordinatesType, const TArray< FVector2D > & InputCoordinates, EGoogleARCoreCoordinates2DType OutputCoordinatesType, TArray< FVector2D > & OutputCoordinates)`	`void` Transforms an array of 2D coordinates into a different 2D coordinate system.

Public static functions

ARCoreLineTrace

bool ARCoreLineTrace(
  UObject *WorldContextObject,
  const FVector2D & ScreenPosition,
  TSet< EGoogleARCoreLineTraceChannel > TraceChannels,
  TArray< FARTraceResult > & OutHitResults
)

Traces a ray from the user's device in the direction of the given location in the camera view.

Intersections with detected scene geometry are returned, sorted by distance from the device; the nearest intersection is returned first.

Details

Parameters

`WorldContextObject`	The world context.
`ScreenPosition`	The position on the screen to cast the ray from.
`TraceChannels`	A set of EGoogleARCoreLineTraceChannel indicate which type of line trace it should perform.
`OutHitResults`	The list of hit results sorted by distance.

Returns

True if there is a hit detected.

ARCoreLineTraceRay

bool ARCoreLineTraceRay(
  UObject *WorldContextObject,
  const FVector & Start,
  const FVector & End,
  TSet< EGoogleARCoreLineTraceChannel > TraceChannels,
  TArray< FARTraceResult > & OutHitResults
)

Traces a ray along the given line.

Intersections with detected scene geometry are returned, sorted by distance from the start of the line; the nearest intersection is returned first.

Details

Parameters

`WorldContextObject`	The world context.
`Start`	The start of line segment.
`End`	The end of line segment.
`TraceChannels`	A set of EGoogleARCoreLineTraceChannel indicate which type of line trace it should perform.
`OutHitResults`	The list of hit results sorted by distance.

Returns

True if there is a hit detected.

AcquireCameraImage

EGoogleARCoreFunctionStatus AcquireCameraImage(
  UGoogleARCoreCameraImage *& OutLatestCameraImage
)

Acquire a CPU-accessible camera image.

Details

Parameters

OutLatestCameraImage

A place to store the pointer to a new UGoogleARCoreCameraImage instance.

Returns

An EGoogleARCoreFunctionStatus. Possible value: Success, ResourceExhausted, NotAvailable.

AcquirePointCloud

EGoogleARCoreFunctionStatus AcquirePointCloud(
  UGoogleARCorePointCloud *& OutLatestPointCloud
)

Acquires latest point cloud.

This will make the point cloud remain valid unless you call UGoogleARCrePointCloud::ReleasePointCloud(). Be aware that this function could fail if the maximal number of point cloud has been acquired.

Details

Parameters

OutLatestPointCloud

A pointer point to the latest point cloud.

Returns

An EGoogleARCoreFunctionStatus. Possible value: Success, SessionPaused, ResourceExhausted.

GetCameraImageIntrinsics

EGoogleARCoreFunctionStatus GetCameraImageIntrinsics(
  UGoogleARCoreCameraIntrinsics *& OutCameraIntrinsics
)

Get the camera intrinsics for the camera image (CPU image).

Details

Parameters

OutCameraIntrinsics

The output intrinsics object.

GetCameraTexture

UTexture * GetCameraTexture()

Get the pass-through camera texture that GoogleARCore plugin will use to render the passthrough camera background.

Note that UTexture object this function returns may change every frame. If you want to use the camera texture, you should call the function every frame and update the texture parameter in your material.

Details
Returns	A pointer to the UTexture that will be used to render the passthrough camera background.

GetCameraTextureIntrinsics

EGoogleARCoreFunctionStatus GetCameraTextureIntrinsics(
  UGoogleARCoreCameraIntrinsics *& OutCameraIntrinsics
)

Get the camera intrinsics for the camera texture (GPU image).

Details

Parameters

OutCameraIntrinsics

The output intrinsics object.

GetLightEstimation

void GetLightEstimation(
  FGoogleARCoreLightEstimate & OutLightEstimate
)

Gets the latest light estimation.

Details

Parameters

OutLightEstimate

The struct that describes the latest light estimation.

GetPointCloud

EGoogleARCoreFunctionStatus GetPointCloud(
  UGoogleARCorePointCloud *& OutLatestPointCloud
)

Gets the latest point cloud that will be only available for this frame.

If you want to keep the point cloud data, you can either copy it to your own struct or call AcquireLatestPointCloud() to avoid the copy.

Details

Parameters

OutLatestPointCloud

A pointer point to the latest point cloud.

Returns

An EGoogleARCoreFunctionStatus. Possible value: Success, SessionPaused, ResourceExhausted.

GetPose

void GetPose(
  FTransform & OutPose
)

Gets the latest tracking pose of the ARCore device in Unreal AR Tracking Space.

Note that ARCore motion tracking has already integrated with HMD and the motion controller interface. Use this function only if you need to implement your own tracking component.

Details

Parameters

OutPose

The latest device pose.

Returns

True if the pose is updated successfully for this frame.

GetTrackingFailureReason

EGoogleARCoreTrackingFailureReason GetTrackingFailureReason()

Returns the reason when UARBlueprintLibrary::GetTrackingQuality() returns NotTracking, or UGoogleARCoreFrameFunctionLibrary::GetTrackingState returns Paused.

In scenarios when multiple causes result in tracking failures, this reports the most actionable failure reason.

Details
Returns	A EGoogleARCoreTrackingFailureReason enum that describes the tracking failure reason.

GetTrackingState

EGoogleARCoreTrackingState GetTrackingState()

Returns the current ARCore session status.

Details
Returns	A EARSessionStatus enum that describes the session status.

GetUpdatedARPins

void GetUpdatedARPins(
  TArray< UARPin * > & OutAnchorList
)

Gets a list of UARPin objects that were changed in this frame.

Details

Parameters

OutAnchorList

An array that contains the updated UARPin.

GetUpdatedAugmentedFaces

void GetUpdatedAugmentedFaces(
  TArray< UGoogleARCoreAugmentedFace * > & OutFaceList
)

Gets a list of UGoogleARCoreAugmentedFace objects that were changed in this frame.

Details

Parameters

OutFaceList

An array that contains the updated UGoogleARCoreAugmentedFace.

GetUpdatedAugmentedImages

void GetUpdatedAugmentedImages(
  TArray< UGoogleARCoreAugmentedImage * > & OutImageList
)

Gets a list of UGoogleARCoreAugmentedImage objects that were changed in this frame.

Details

Parameters

OutImageList

An array that contains the updated UGoogleARCoreAugmentedImage.

GetUpdatedPlanes

void GetUpdatedPlanes(
  TArray< UARPlaneGeometry * > & OutPlaneList
)

Gets a list of UARPlaneGeometry objects that were changed in this frame.

Details

Parameters

OutPlaneList

An array that contains the updated UARPlaneGeometry.

GetUpdatedTrackable

void GetUpdatedTrackable(
  TArray< T * > & OutTrackableList
)

Template function to get the updated trackables in this frame a given trackable type.

GetUpdatedTrackablePoints

void GetUpdatedTrackablePoints(
  TArray< UARTrackedPoint * > & OutTrackablePointList
)

Gets a list of UARTrackedPoint objects that were changed in this frame.

Details

Parameters

OutTrackablePointList

An array that contains the updated UARTrackedPoint.

TransformARCoordinates2D

void TransformARCoordinates2D(
  EGoogleARCoreCoordinates2DType InputCoordinatesType,
  const TArray< FVector2D > & InputCoordinates,
  EGoogleARCoreCoordinates2DType OutputCoordinatesType,
  TArray< FVector2D > & OutputCoordinates
)

Transforms an array of 2D coordinates into a different 2D coordinate system.

This will account for the display rotation, and any additional required adjustment.

Some examples of useful conversions: To transform screen space UVs for texture space UVs to rendering pass-through camera texture: Viewport -> Texture; To transform a point found by a computer vision algorithm in the pass-through camera image into a point on the viewport: Image -> Viewport;

Details

Parameters

`InputCoordinatesType`	The coordinate system used by InputCoordinates.
`InputCoordinates`	The input 2d coordinates.
`OutputCoordinatesType`	The coordinate system to transform to.
`OutputCoordinates`	The output 2d coordinates.