/// <summary>
/// Creates a new anchor at the specified geodetic location and orientation
/// relative to the Earth.
///
/// Latitude and longitude are defined by the
/// <a href="https://en.wikipedia.org/wiki/World_Geodetic_System">WGS84
/// specification</a>, and altitude values are defined by the elevation above
/// the WGS84 ellipsoid.
///
/// Creating anchors near the north pole or south pole is not supported. If
/// the latitude is within 0.1 degrees of the north pole or south pole (90
/// degrees or -90 degrees), this function will return <c>null</c>.
///
/// The rotation provided by <paramref name="eunRotation"/> is a rotation
/// with respect to an east-up-north 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 north.
///
/// To create a quaternion that represents a clockwise angle theta from
/// north around the +Y anchor frame axis, use the following formula:
/// <code>
/// Quaternion.AngleAxis(180f - theta, Vector3.up);
/// </code>
///
/// An anchor's tracking state will be TrackingState.None while
/// <see cref="AREarthManager.EarthTrackingState"/> is TrackingState.None.
/// The tracking state will permanently become TrackingState.None if the
/// configuration is set to <see cref="GeospatialMode"/>.<c>Disabled</c>.
/// </summary>
/// <param name="anchorManager">The ARAnchorManager instance.</param>
/// <param name="latitude">
/// The latitude of the anchor relative to the WGS84 ellipsoid.</param>
/// <param name="longitude">
/// The longitude of the anchor relative to the WGS84 ellipsoid.</param>
/// <param name="altitude">
/// The altitude of the anchor relative to the WGS84 ellipsoid.</param>
/// <param name="eunRotation">The rotation of the anchor with respect to
/// the east-up-north coordinate frame where X+ points east, Y+ points up
/// away from gravity, and Z+ points north. A rotation about the Y+ axis
/// creates a rotation counterclockwise from north.</param>
/// <returns>
/// If successful, a <see cref="ARGeospatialAnchor"/>, otherwise, <c>null</c>.
/// </returns>
public static ARGeospatialAnchor AddAnchor(
this ARAnchorManager anchorManager, double latitude, double longitude,
double altitude, Quaternion eunRotation)
{
IntPtr earthHandle = SessionApi.AcquireEarth(
ARCoreExtensions._instance.currentARCoreSessionHandle);
if (earthHandle == IntPtr.Zero)
{
Debug.LogError("Failed to acquire earth.");
return(null);
}
IntPtr anchorHandle = EarthApi.AddAnchor(
ARCoreExtensions._instance.currentARCoreSessionHandle,
earthHandle, latitude, longitude, altitude, eunRotation);
if (anchorHandle == IntPtr.Zero)
{
Debug.LogError("Failed to add geospatial anchor.");
return(null);
}
// Create the GameObject that is the Geospatial Anchor.
ARGeospatialAnchor anchor =
new GameObject(_geospatialAnchorName).AddComponent <ARGeospatialAnchor>();
if (anchor)
{
anchor.SetAnchorHandle(anchorHandle);
}
// Parent the new Geospatial Anchor to the session origin.
anchor.transform.SetParent(
ARCoreExtensions._instance.SessionOrigin.trackablesParent, false);
return(anchor);
}