darax
commented
4 years ago Hi @Connor-Kerwin,
On Android or iOS we wait until ARFoundation has a tracking ARSession before starting.
before the block you posted is this code:
#if UNITY_ANDROID || UNITY_IOS
ARSession.stateChanged += ARSession_stateChanged;
// Wait for a valid AR Session in case we are starting before ARFoundation is ready.
if (ARSession.state == ARSessionState.SessionTracking)
{
CompleteARFoundationInitialization();
}
else
{
Debug.Log($"ARSession not yet available ({ARSession.state}, will complete initialization when session is running");
}
#elif UNITY_WSA || WINDOWS_UWPIf the session is already running we will call CompleteARFoundationInitialization (see below) immediately. This will raise the OnSessionCreated event.
If the session isn't tracking, ARSession_stateChanged does this, waiting until the session is tracking:
#if UNITY_ANDROID || UNITY_IOS
/// <summary>
/// Called when ARFoundation changes states.
/// We wait until the ARFoundation session is tracking to complete initialization
/// </summary>
/// <param name="obj">state change arguments</param>
private void ARSession_stateChanged(ARSessionStateChangedEventArgs obj)
{
Debug.Log($"ARSession state changed to {obj.state}");
if (obj.state == ARSessionState.SessionTracking && !ARSessionInitialized)
{
CompleteARFoundationInitialization();
}
}
... / snip / ...
#if UNITY_ANDROID || UNITY_IOS
/// <summary>
/// Called the first time ARFoundation indicates the session is tracking and
/// thus can be relied upon to be fully initialized.
/// </summary>
protected void CompleteARFoundationInitialization()
{
session.Session = arSession.subsystem.nativePtr.GetPlatformPointer();
// Ask for ar frames to process
arCameraManager.frameReceived += ArCameraManager_frameReceived;
ARSessionInitialized = true;
OnSessionCreated();
}
#endif
Connor-Kerwin
craigktreasure
Looking through the SpatialAnchorManager it seems as though the call to OnSessionCreated is only invoked on the UNITY_WSA and WINDOWS_UWP platform; running on android or iOS this will never get called.
I need to do some extra work with a newly created CloudSpatialAnchorSession before it's started (to set some extra properties), and this is the only reliable way I can do so without editing the SpatialAnchorManager class itself, unless there is a better alternative that I'm missing?