com.unity.netcode.gameobjects@2.0.0-exp.4

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).

## [2.0.0-exp.4] - 2024-05-31

### Added

- Added `NetworkRigidbodyBase.AttachToFixedJoint` and `NetworkRigidbodyBase.DetachFromFixedJoint` to replace parenting for rigid bodies that have `NetworkRigidbodyBase.UseRigidBodyForMotion` enabled. (#2933)
- Added `NetworkBehaviour.OnNetworkPreSpawn` and `NetworkBehaviour.OnNetworkPostSpawn` methods that provide the ability to handle pre and post spawning actions during the `NetworkObject` spawn sequence. (#2912)
- Added a client-side only `NetworkBehaviour.OnNetworkSessionSynchronized` convenience method that is invoked on all `NetworkBehaviour`s after a newly joined client has finished synchronizing with the network session in progress. (#2912)
- Added `NetworkBehaviour.OnInSceneObjectsSpawned` convenience method that is invoked when all in-scene `NetworkObject`s have been spawned after a scene has been loaded or upon a host or server starting. (#2912)

### Fixed

- Fixed issue where non-authoritative rigid bodies with `NetworkRigidbodyBase.UseRigidBodyForMotion` enabled would constantly log errors about the renderTime being before `StartTimeConsumed`. (#2933)
- Fixed issue where in-scene placed NetworkObjects could be destroyed if a client disconnects early and/or before approval. (#2924)
- Fixed issue where a `NetworkObject` component's associated `NetworkBehaviour` components would not be detected if scene loading is disabled in the editor and the currently loaded scene has in-scene placed `NetworkObject`s. (#2912)
- Fixed issue where an in-scene placed `NetworkObject` with `NetworkTransform` that is also parented under a `GameObject` would not properly synchronize when the parent `GameObject` had a world space position other than 0,0,0. (#2898)

### Changed

- Change all the access modifiers of test class from Public to Internal (#2930)
- Changed messages are now sorted by enum values as opposed to ordinally sorting the messages by their type name. (#2929)
- Changed `NetworkClient.SessionModeTypes` to `NetworkClient.NetworkTopologyTypes`. (#2875)
- Changed `NetworkClient.SessionModeType` to `NetworkClient.NetworkTopologyType`. (#2875)
- Changed `NetworkConfig.SessionMode` to `NeworkConfig.NetworkTopology`. (#2875)

Runtime/Spawning/NetworkSpawnManager.cs

@@ -810,20 +810,27 @@ namespace Unity.Netcode
                 networkObject.DontDestroyWithOwner = sceneObject.DontDestroyWithOwner;
                 networkObject.Ownership = (NetworkObject.OwnershipStatus)sceneObject.OwnershipFlags;
 
+
+                var nonNetworkObjectParent = false;
                 // SPECIAL CASE FOR IN-SCENE PLACED:  (only when the parent has a NetworkObject)
                 // This is a special case scenario where a late joining client has joined and loaded one or
                 // more scenes that contain nested in-scene placed NetworkObject children yet the server's
                 // synchronization information does not indicate the NetworkObject in question has a parent.
                 // Under this scenario, we want to remove the parent before spawning and setting the transform values.
-                if (sceneObject.IsSceneObject && !sceneObject.HasParent && networkObject.transform.parent != null)
+                if (sceneObject.IsSceneObject && networkObject.transform.parent != null)
                 {
+                    var parentNetworkObject = networkObject.transform.parent.GetComponent<NetworkObject>();
                     // if the in-scene placed NetworkObject has a parent NetworkObject but the synchronization information does not
                     // include parenting, then we need to force the removal of that parent
-                    if (networkObject.transform.parent.GetComponent<NetworkObject>() != null)
+                    if (!sceneObject.HasParent && parentNetworkObject)
                     {
                         // remove the parent
                         networkObject.ApplyNetworkParenting(true, true);
                     }
+                    else if (sceneObject.HasParent && !parentNetworkObject)
+                    {
+                        nonNetworkObjectParent = true;
+                    }
                 }
 
                 // Set the transform unless we were spawned by a prefab handler
@@ -833,7 +840,7 @@ namespace Unity.Netcode
                 {
                     // If world position stays is true or we have auto object parent synchronization disabled
                     // then we want to apply the position and rotation values world space relative
-                    if (worldPositionStays || !networkObject.AutoObjectParentSync)
+                    if ((worldPositionStays && !nonNetworkObjectParent) || !networkObject.AutoObjectParentSync)
                     {
                         networkObject.transform.position = position;
                         networkObject.transform.rotation = rotation;
@@ -917,6 +924,8 @@ namespace Unity.Netcode
                     Debug.LogError("Spawning NetworkObjects with nested NetworkObjects is only supported for scene objects. Child NetworkObjects will not be spawned over the network!");
                 }
             }
+            // Invoke NetworkBehaviour.OnPreSpawn methods
+            networkObject.InvokeBehaviourNetworkPreSpawn();
 
             // DANGO-TODO: It would be nice to allow users to specify which clients are observers prior to spawning
             // For now, this is the best place I could find to add all connected clients as observers for newly
@@ -957,12 +966,18 @@ namespace Unity.Netcode
                 }
             }
             SpawnNetworkObjectLocallyCommon(networkObject, networkId, sceneObject, playerObject, ownerClientId, destroyWithScene);
+
+            // Invoke NetworkBehaviour.OnPostSpawn methods
+            networkObject.InvokeBehaviourNetworkPostSpawn();
         }
 
         /// <summary>
         /// This is only invoked to instantiate a serialized NetworkObject via
         /// <see cref="NetworkObject.AddSceneObject(in NetworkObject.SceneObject, FastBufferReader, NetworkManager, bool)"/>
         /// </summary>
+        /// <remarks>
+        /// IMPORTANT: Pre spawn methods need to be invoked from within <see cref="NetworkObject.AddSceneObject"/>.
+        /// </remarks>
         internal void SpawnNetworkObjectLocally(NetworkObject networkObject, in NetworkObject.SceneObject sceneObject, bool destroyWithScene)
         {
             if (networkObject == null)
@@ -975,7 +990,11 @@ namespace Unity.Netcode
                 throw new SpawnStateException($"[{networkObject.name}] Object-{networkObject.NetworkObjectId} is already spawned!");
             }
 
+            // Do not invoke Pre spawn here (SynchronizeNetworkBehaviours needs to be invoked prior to this)
             SpawnNetworkObjectLocallyCommon(networkObject, sceneObject.NetworkObjectId, sceneObject.IsSceneObject, sceneObject.IsPlayerObject, sceneObject.OwnerClientId, destroyWithScene);
+
+            // It is ok to invoke NetworkBehaviour.OnPostSpawn methods
+            networkObject.InvokeBehaviourNetworkPostSpawn();
         }
 
         private void SpawnNetworkObjectLocallyCommon(NetworkObject networkObject, ulong networkId, bool sceneObject, bool playerObject, ulong ownerClientId, bool destroyWithScene)
@@ -1226,7 +1245,7 @@ namespace Unity.Netcode
                     {
                         // If it is an in-scene placed NetworkObject then just despawn and let it be destroyed when the scene
                         // is unloaded. Otherwise, despawn and destroy it.
-                        var shouldDestroy = !(networkObjects[i].IsSceneObject != null && networkObjects[i].IsSceneObject.Value);
+                        var shouldDestroy = !(networkObjects[i].IsSceneObject == null || (networkObjects[i].IsSceneObject != null && networkObjects[i].IsSceneObject.Value));
 
                         // If we are going to destroy this NetworkObject, check for any in-scene placed children that need to be removed
                         if (shouldDestroy)
@@ -1307,6 +1326,7 @@ namespace Unity.Netcode
             var networkObjects = UnityEngine.Object.FindObjectsOfType<NetworkObject>();
 #endif
             var isConnectedCMBService = NetworkManager.CMBServiceConnection;
+            var networkObjectsToSpawn = new List<NetworkObject>();
             for (int i = 0; i < networkObjects.Length; i++)
             {
                 if (networkObjects[i].NetworkManager == NetworkManager)
@@ -1323,9 +1343,17 @@ namespace Unity.Netcode
                         }
 
                         SpawnNetworkObjectLocally(networkObjects[i], GetNetworkObjectId(), true, false, ownerId, true);
+                        networkObjectsToSpawn.Add(networkObjects[i]);
                     }
                 }
             }
+
+            // Notify all in-scene placed NetworkObjects have been spawned
+            foreach (var networkObject in networkObjectsToSpawn)
+            {
+                networkObject.InternalInSceneNetworkObjectsSpawned();
+            }
+            networkObjectsToSpawn.Clear();
         }
 
         internal void OnDespawnObject(NetworkObject networkObject, bool destroyGameObject, bool modeDestroy = false)