UI NetworkObject Parenting ignores `SetParent` `worldPositionStays`

Description

When using SetParent on Server for UI, Client ignores the worldPositionStays param, throws a warning: Parent of RectTransform is being set with parent property

Reproduce Steps

1. Start Server
2. Start Client, connect to Server
3. On Server: Instantiate and Spawn Canvas with Network Object (_parentInstance):

_parentInstance = Instantiate(_parent);
_parentNetworkObject = _parentInstance.GetComponent<NetworkObject>();
_parentNetworkObject.Spawn();

1. On Server: Instantiate and Spawn Image with Network Object (_childInstance):

_childInstance = Instantiate(_child);
_childNetworkObject = _childInstance.GetComponent<NetworkObject>();
_childNetworkObject.Spawn();

1. On Server: set _parentInstance as parent of _childInstance, with worldPositionStays param set to false:

_childInstance.transform.SetParent(_parentInstance.transform, worldPositionStays: false);

Actual Outcome

• ✅ On Server: Image is placed at the center of Canvas
• ❌ On Client: Image is placed at the bottom left of Canvas, as if it ignored the worldPositionStays: false

Expected Outcome

• ✅ On Server: Image is placed at the center of Canvas
• ✅ On Client: Image is placed at the center of Canvas

Environment

• OS: macOS Monterey
• Unity Version: 2021.3.2f1
• Netcode Version: 1.0.0
• ParrelSync: 1.5.1

Additional Context

Full warning stack trace:

Parent of RectTransform is being set with parent property. Consider using the SetParent method instead, with the worldPositionStays argument set to false. This will retain local orientation and scale rather than world orientation and scale, which can prevent common UI scaling issues.
UnityEngine.Transform:set_parent (UnityEngine.Transform)
Unity.Netcode.NetworkObject:ApplyNetworkParenting () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Core/NetworkObject.cs:739)
Unity.Netcode.NetworkObject:OnTransformParentChanged () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Core/NetworkObject.cs:667)
SampleSpawner:SpawnUI () (at Assets/Scripts/SampleSpawner.cs:33)
SampleSpawner:OnNetworkSpawn () (at Assets/Scripts/SampleSpawner.cs:17)
Unity.Netcode.NetworkBehaviour:InternalOnNetworkSpawn () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Core/NetworkBehaviour.cs:438)
Unity.Netcode.NetworkObject:InvokeBehaviourNetworkSpawn () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Core/NetworkObject.cs:767)
Unity.Netcode.NetworkSpawnManager:SpawnNetworkObjectLocallyCommon (Unity.Netcode.NetworkObject,ulong,bool,bool,ulong,bool) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Spawning/NetworkSpawnManager.cs:552)
Unity.Netcode.NetworkSpawnManager:SpawnNetworkObjectLocally (Unity.Netcode.NetworkObject,ulong,bool,bool,ulong,bool) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Spawning/NetworkSpawnManager.cs:453)
Unity.Netcode.NetworkObject:SpawnInternal (bool,ulong,bool) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0/Runtime/Core/NetworkObject.cs:425)
SampleNetworkController:SpawnController () (at Assets/Scripts/SampleNetworkController.cs:21)
UnityEngine.EventSystems.EventSystem:Update () (at Library/PackageCache/com.unity.ugui@1.0.0/Runtime/EventSystem/EventSystem.cs:501)

I attach a barebones Unity Project to illustrate this. It uses ParrelSync to simulate a Client (I’ve tried making an actual macOS build, it changes nothing).

unity-sample.zip

Steps to reproduce in project

1. Open 2 Instances of the Project using ParrelSync, or make a build, which would act as Instance 2
2. Open SampleScene
3. Project Instance 1 (Server): start Server via “Start Server” UI button
4. Project Instance 2 (Client): start Client via “Start Client” UI button
5. Project Instance 1 (Server): click “Spawn Controller” UI button, which:
   • spawns “Controller” prefab
   • “Controller” instance OnNetworkSpawn method does the steps in Reproduce Steps section above

You should see the Image parented into Canvas in different spots on Server and Client.

[MtPython]

@NoelStephensUnity Thank you, just tested, it works on my side too (from that branch).

I’ll text here if I find anything not working related to this, but otherwise I believe this issue can be closed. 👍

[NoelStephensUnity]

@MtPython Just following up: Running your more complex setup from the following branch: fix/parenting-does-not-preserve-worldpositionstays-option Yields the following results: (if you want to use that branch for the time being, you will need to remove your NetworkTransforms) 👍