GARSession(Geospatial)

Category adding Geospatial functionality to GARSession.

Summary

Public methods

checkVPSAvailabilityAtCoordinate:completionHandler:
Gets the availability of the Visual Positioning System (VPS) at a specified horizontal position.
createAnchorWithCoordinate:altitude:eastUpSouthQAnchor:error:
nullable GARAnchor *
Creates a Geospatial anchor at the specified geodetic location and orientation relative to the Earth.
createAnchorWithCoordinate:altitudeAboveTerrain:eastUpSouthQAnchor:error:
nullable GARAnchor *
Creates a Terrain anchor at the specified geodetic location, altitude relative to the horizontal position’s terrain and orientation relative to the Earth.
geospatialTransformFromTransform:error:
Converts the provided transform to a GARGeospatialTransform with respect to the Earth.
isGeospatialModeSupported:
BOOL
Determines whether the given geospatial mode is supported on the current device and OS version.
transformFromGeospatialCoordinate:altitude:eastUpSouthQTarget:error:
matrix_float4x4
Converts the provided Earth specified horizontal position, altitude and rotation with respect to an east-up-south coordinate frame to a local transform in world coordinate space.

Public methods

checkVPSAvailabilityAtCoordinate:completionHandler:

- (GARVPSAvailabilityFuture *)checkVPSAvailabilityAtCoordinate:
(CLLocationCoordinate2D) coordinate
completionHandler:
(void(^)(GARVPSAvailability availability)) completionHandler

Gets the availability of the Visual Positioning System (VPS) at a specified horizontal position.

The availability of VPS in a given location helps to improve the quality of Geospatial localization and tracking accuracy.

This launches an asynchronous operation used to query the Google Cloud ARCore API. This function returns a GARVPSAvailabilityFuture which can be used to obtain the task's result. Its initial GARFutureState will be set to GARFutureStatePending. When the operation is completed, its GARFutureState will be set to GARFutureStateDone, and GARVPSAvailabilityFuture.state can be used to obtain the operation's result.

You may provide an optional completionHandler, which will be invoked when the operation is completed, unless the GARVPSAvailabilityFuture has been cancelled. The callback will be called on the Main thread.

Your app must be properly set up to communicate with the Google Cloud ARCore API in order to obtain a result from this call. See Check VPS Availability for more details on setup steps and usage examples.

Details
Parameters
coordinate
The coordinate at which to check availability.
completionHandler
Completion handler to be invoked on the Main thread, if not nil.
Returns
A handler that can be polled or cancelled. If the operation is cancelled, no callback will be invoked.
Extends class GARSession.

createAnchorWithCoordinate:altitude:eastUpSouthQAnchor:error:

- (nullable GARAnchor *)createAnchorWithCoordinate:
(CLLocationCoordinate2D) coordinate
altitude:
(CLLocationDistance) altitude
eastUpSouthQAnchor:
(simd_quatf) eastUpSouthQAnchor
error:
(NSError **) error

Creates a Geospatial anchor at the specified geodetic location and orientation relative to the Earth.

Latitude and longitude are defined by the WGS84 specification, and altitude values are defined as the elevation above the WGS84 ellipsoid in meters.

The rotation provided by eastUpSouthQAnchor is a rotation with respect to an east-up-south coordinate frame. An identity rotation will have the anchor oriented such that X+ points to the east, Y+ points up away from the center of the earth, and Z+ points to the south.

An anchor's GARAnchor.trackingState will be GARTrackingStatePaused while GAREarth is GARTrackingStatePaused. The tracking state will permanently become GARTrackingStateStopped if the GARSession configuration is set to GARGeospatialModeDisabled.

Creating anchors near the north pole or south pole is not supported. If the latitude is within 0.1° of the north pole or south pole (90° or -90 °), this function will output GARSessionErrorCodeInvalidArgument and the anchor will fail to be created.

Details
Parameters
coordinate
The latitude and longitude associated with the location, specified using the WGS84 reference frame. This must not be within .1° of the North or South pole (i.e. +- 90°).
altitude
Altitude in reference to the WGS 84 ellipsoid, in meters. Positive values indicate altitudes above approximate sea level. Negative values indicate altitudes below approximate sea level.
eastUpSouthQAnchor
Represents the quaternion from the anchor to East-Up-South (EUS) coordinates (i.e., +X points East, +Y points up, and +Z points South).
error
Out param for an NSError. Possible error codes:
Returns
The new anchor, or nil if there was an error.
Extends class GARSession.

createAnchorWithCoordinate:altitudeAboveTerrain:eastUpSouthQAnchor:error:

- (nullable GARAnchor *)createAnchorWithCoordinate:
(CLLocationCoordinate2D) coordinate
altitudeAboveTerrain:
(CLLocationDistance) altitudeAboveTerrain
eastUpSouthQAnchor:
(simd_quatf) eastUpSouthQAnchor
error:
(NSError **) error

Creates a Terrain anchor at the specified geodetic location, altitude relative to the horizontal position’s terrain and orientation relative to the Earth.

Terrain means the ground, or ground floor inside a building with VPS coverage.

The specified altitudeAboveTerrain is interpreted to be relative to the Earth's terrain (or floor) at the specified latitude/longitude geodetic coordinates, rather than relative to the WGS-84 ellipsoid. Specifying an altitudeAboveTerrain of 0 will position the anchor directly on the terrain (or floor) whereas specifying a positive altitudeAboveTerrain will position the anchor above the terrain (or floor), against the direction of gravity.

This function schedules a task to resolve the anchor's pose using the given parameters. You may resolve multiple anchors at a time, but a session cannot be tracking more than 100 Terrain anchors at time. Attempting to resolve more than 100 Terrain anchors will result in GARSessionErrorCodeResourceExhausted.

If this function returns error nil, the terrain anchor's GARAnchor.terrainState will be GARTerrainAnchorStateTaskInProgress, and its tracking state will be GARTrackingStatePaused. This anchor remains in this state until its pose has been successfully resolved. If the resolving task results in an error, the tracking state will be set to GARTrackingStateStopped.

Latitude and longitude are defined by the WGS84 specification, and altitude values are defined as the elevation above the WGS84 ellipsoid in meters.

The rotation provided by eastUpSouthQAnchor is a rotation with respect to an east-up-south coordinate frame. An identity rotation will have the anchor oriented such that X+ points to the east, Y+ points up away from the center of the earth, and Z+ points to the south.

An anchor's GARAnchor.trackingState will be GARTrackingStateTracking while GAREarth is GARTrackingStatePaused. The tracking state will permanently become GARTrackingStateStopped if the GARSession configuration is set to GARGeospatialModeDisabled.

Creating anchors near the north pole or south pole is not supported. If the latitude is within 0.1° of the north pole or south pole (90° or -90°), this function will output GARSessionErrorCodeInvalidArgument and the anchor will fail to be created.

Details
Parameters
coordinate
The latitude and longitude associated with the location, specified using the WGS84 reference frame. This must not be within .1° of the North or South pole (i.e. +- 90°).
altitudeAboveTerrain
Altitude above Earth's terrain, in meters.
eastUpSouthQAnchor
Represents the quaternion from the anchor to East-Up-South (EUS) coordinates (i.e., +X points East, +Y points up, and +Z points South).
error
Out param for an NSError. Possible error codes:
Returns
The new anchor, or nil if there was an error.
Extends class GARSession.

geospatialTransformFromTransform:error:

- (nullable GARGeospatialTransform *)geospatialTransformFromTransform:
(matrix_float4x4) transform
error:
(NSError **) error

Converts the provided transform to a GARGeospatialTransform with respect to the Earth.

Its heading will be zero for a GARGeospatialTransform returned from this method.

Details
Parameters
transform
The local transform in world coordinate space.
error
Out param for an NSError. Possible error codes:
Returns
GARGeospatialTransform, or nil if there was an error.
Extends class GARSession.

isGeospatialModeSupported:

- (BOOL)isGeospatialModeSupported:
(GARGeospatialMode) geospatialMode

Determines whether the given geospatial mode is supported on the current device and OS version.

If this returns NO, then configuring the session with the given geospatial mode will fail with the error code GARSessionErrorCodeConfigurationNotSupported. A device may be incompatible with a given mode due to insufficient sensor capabilities.

Details
Parameters
geospatialMode
The Geospatial mode.
Returns
YES if the geospatialMode is supported, NO otherwise.
Extends class GARSession.

transformFromGeospatialCoordinate:altitude:eastUpSouthQTarget:error:

- (matrix_float4x4)transformFromGeospatialCoordinate:
(CLLocationCoordinate2D) coordinate
altitude:
(CLLocationDistance) altitude
eastUpSouthQTarget:
(simd_quatf) eastUpSouthQTarget
error:
(NSError **) error

Converts the provided Earth specified horizontal position, altitude and rotation with respect to an east-up-south coordinate frame to a local transform in world coordinate space.

Details
Parameters
coordinate
The latitude and longitude associated with the location, specified using the WGS84 reference frame. This must not be within .1° of the North or South pole (i.e. +- 90°).
altitude
Altitude in reference to the WGS 84 ellipsoid, in meters. Positive values indicate altitudes above approximate sea level. Negative values indicate altitudes below approximate sea level.
eastUpSouthQTarget
Represents the quaternion from the target to East-Up-South (EUS) coordinates (i.e., +X points East, +Y points up, and +Z points South).
error
Out param for an NSError. Possible error codes:
Returns
a local transform in world coordinate space.
Extends class GARSession.