[SyncVar] GameObject problems - how to set a syncvar to null ?

Unity Engine
1

Trying to understand the [SyncVar] in combination with GameObject.

The idea is that objects in my game retain a reference to the player who owns them. I have a syncvar that points to the owning player.

When a player disconnects, I was previously setting owner = null but this does not trigger the syncvar update hook. So - I made a global shared GameObject with a NetworkIdentity that I designate the ‘null’ object, instead. So now I can set owner = nullObject on the server which triggers the syncvar hook.

But, when I set owner = nullObject I get some behaviour that I don’t quite understand.

    [SyncVar(hook="_OnOwnerChange")]
    public GameObject owner;
    void _OnOwnerChange( GameObject newOwner ) {
        owner = newOwner;

        Debug.Log("OnOwnerChange - owner = " + owner.ToString());
        Debug.Log("OnOwnerChange - newOwner = " + newOwner.ToString());

        OnOwnerChange(); // done this way so OnOwnerChange can be overriddden!
    }

With the result in the console:

OnOwnerChange - owner = mercior (UnityEngine.GameObject)
OnOwnerChange - newOwner = NullObject (UnityEngine.GameObject)

I don’t fully understand how the 2 variables can be different? This is in the console of a HOST that I am testing with (rather than a dedicated server) so perhaps I am seeing this message from the client-side rather than the server? And then the client can’t set ‘owner’ because it is a syncvar??

If so… is there any way I can get around this using a StartHost() setup? Is the SyncVar change hook called at all on the server? Its going to slow development for me a lot if I have to start building a dedicated server and client separately every time I want to test so I am trying to find a solution that will allow me to keep testing in the editor.

2

After writing this I realized that owner == NullObject on the next frame so this is a race condition. I don’t fully understand why its occurring yet but if I (lazily) invoke OnOwnerChange call on the next frame like this

Invoke( "OnOwnerChange", 0 );

Then I can safely check if owner == nullObject in the OnOwnerChange callback.

I’d still appreciate anybody elses input into this behaviour and why it happens!