NetworkTransform Teleport() can fail because IsTeleportingNextFrame gets set back to false

[zachstronaut]

Description

NetworkTransform Teleport() can fail because IsTeleportingNextFrame gets set back to false by CheckForStateChange()

Settings for prefab being teleported:

NetworkObject
SyncOwnerTransformWhenParented = false
AllowOwnerToParent = true

NetworkTransform
Authority Mode = Owner
Switch Transform Space When Parented = true
In Local Space = true

Host Harry with one additional Client Charlie.

Harry spawns the prefab with SpawnWithOwnership() and makes Charlie the owner.

It spawns on Charlie's client and NetworkTransform.OnNetworkSpawn() calls SetState() -> SetStateInternal() -> CheckForStateChange()

CheckForStateChange() sees that InLocalSpace != networkState.InLocalSpace and so it sets IsTeleportingNextFrame=False. But also, networkState.InLocalSpace is set to false rather than true because at the moment of spawning the transform.parent is null:

networkState.InLocalSpace = SwitchTransformSpaceWhenParented ? transform.parent != null : InLocalSpace;

Still on the same frame as OnNetworkSpawn(), Charlie calls Teleport() -> SetStateInternal() which sets IsTeleportingNextFrame = true but then calls CheckForStateChange(). Again, it is still true that InLocalSpace != networkState.InLocalSpace, so it sets IsTeleportingNextFrame=False!

When TryCommitTransform runs, IsTeleportingNextFrame is false. The Teleport does not happen.

Environment

OS: Windows 11
Unity Version: 6000.1.3f1
Netcode Version: 2.4.2
Netcode Topology: Client-Server

[zachstronaut]

Repro is very straightforward!

ParrelSync with simulated 750ms lag so you can more easily see the problem.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Unity.Netcode;
using Unity.Netcode.Components;

public class Bug3646 : NetworkBehaviour
{
    public Transform position1; // Not at (0,0,0)
    public GameObject prefab;

    void SpawnTestClientOwner()
    {
        var temp = GameObject.Instantiate(prefab, position1.position, Quaternion.identity) as GameObject;

        NetworkObject networkObj = temp.GetComponent<NetworkObject>();
        networkObj.SpawnWithOwnership( 1 ); // lazy hardcoded this, should be other non-host client tho ;)
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Unity.Netcode;
using Unity.Netcode.Components;

public class Bug3646Client : NetworkBehaviour
{
    public override void OnNetworkSpawn()
    {
        if (IsOwner)
        {
            var netTransform = GetComponent<NetworkTransform>();
            netTransform.Teleport(transform.localPosition + Vector3.right * 5f, transform.localRotation, transform.localScale);
        }
    }
}

Because of a bug with the owner authoritative NetworkTransform, on the host (who does not own this spawned object) you will see the object interpolate across the screen instead of instantly teleporting to the position from the Teleport() call.

[zachstronaut]

So Teleport() just doesn't work at all for a client authoritative NetworkTransform that is at the root of a scene when using the above NetworkObject and NetworkTransform settings?

[NoelStephensUnity]

So Teleport() just doesn't work at all for a client authoritative NetworkTransform that is at the root of a scene when using the above NetworkObject and NetworkTransform settings?

It isn't that it can be done, the scenario you are running into looks like this:

• Host instantiates and spawns the network prefab with a client, other than the host, as the owner.
  • CreateObjectMessage is queued and will be sent at the end of this frame.
  • Any visible component (i.e. MeshRenderer etc) will be visible the very frame this message is received.
  • On the host side it will be visible in the location it was spawned by the host
• Once the CreateObjectMessage is received by the owner (+latency to host)
  • The owning client sends a teleport.
    • This is not sent until the next network tick (+~1-33ms depending upon where it is in the current tick)
• The teleport message is received by all observers.
• The spawned object is now in its correct location based on where the owning client wanted to teleport it.

If you think about the timing here, there is a reasonable period of time between the host spawning and the owning client teleporting it. What you really need is to have some way to not make the object really "active" until the owning client is ready for it to be active in order to assure when the spawned object is visible by all observers it has already teleported.

Taking your scripts above, I put together a small example of how you can accomplish this without the host side visual anomaly:
SpawnAndTeleport.zip

Here is a video of the end result:

2025-09-09.11-19-42.mov

This project uses the new ComponentController to provide control over when specific components on the spawned object are active.
Since you are using a client-server network topology, I created a custom ComponentController that overrides the "HasAuthority" virtual method and returns true if the client is the owner of the object (i.e. server is always authority over all spawned objects in client-server).

Let me know if this resolves your issue?

[zachstronaut]

@NoelStephensUnity Thanks, I'm taking a look.

However, separately, if you setup a simple test in Netcode 2.4.2 you will see that Teleport() just NEVER works with an InLocalSpace NetworkTransform at the root (that has no parent), and this is indeed a bug.

[zachstronaut]

@NoelStephensUnity the provided zip doesn't work under 2.4.2 because of ComponentController.

It isn't that it can be done

If you think about the timing here, there is a reasonable period of time between the host spawning and the owning client teleporting it. What you really need is to have some way to not make the object really "active" until the owning client is ready for it to be active in order to assure when the spawned object is visible by all observers it has already teleported.

Just to muddy the waters for you a bit, this is interesting:

If you Teleport() twice from the owner in the way I am doing below, the creates a teleportation that works and stops the incorrect interpolation from happening.

By calling twice it seems that CheckForStateChange()'s initial screw up (bug) of setting IsTeleportingNextFrame=false despite a pending teleportation gets fixed the second time through.

    [ContextMenu("RunBug3646 and Fix")]
    void RunBug3646AndFix()
    {
        var temp = GameObject.Instantiate(prefab3646, position3.position, Quaternion.identity) as GameObject;
        NetworkObject networkObj = temp.GetComponent<NetworkObject>();
        networkObj.SpawnWithOwnership( 1 );

        // Re-parent because none of my gameobjects stay at root in my game anyway, and ALSO because there is a bug where Teleport() never works at all for InLocalSpace NetworkTransform that doesn't have a parent.
        networkObj.TrySetParent( parent1 );

        networkObj.GetComponent<Bug3646Client>().Fix_ClientRpc();
    }

public class Bug3646Client : NetworkBehaviour
{
    public override void OnNetworkSpawn()
    {
        if (IsOwner)
        {
            var netTransform = GetComponent<NetworkTransform>();
            Vector3 pos = transform.localPosition + Vector3.right * 5f;
            netTransform.Teleport(pos, transform.localRotation, transform.localScale); // doesn't work
        }
    }

    [ClientRpc]
    public void Fix_ClientRpc()
    {
        if (IsOwner)
        {
            var netTransform = GetComponent<NetworkTransform>();
            Debug.Assert(transform.parent, "Fix won't work with a null parent");
            netTransform.Teleport(transform.localPosition, transform.localRotation, transform.localScale); // doesn't work
            netTransform.Teleport(transform.localPosition, transform.localRotation, transform.localScale); // WORKS!
        }
    }
}

[NoelStephensUnity]

@NoelStephensUnity the provided zip doesn't work under 2.4.2 because of ComponentController.

Right, it would require you to update to v2.5.0 where there are also a bunch of other fixes. Is there a reason why you can't update to v2.5.0?