feat: Add a SessionOwner ObjectStatus and allow InScenePlaced network objects to be distributed

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -10,6 +10,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Added
 
+- Added `NetworkObject.OwnershipStatus.SessionOwner` to allow Network Objects to be distributable and only owned by the Session Owner. This flag will override all other `OwnershipStatus` flags. (#3175)
 - Added `UnityTransport.GetEndpoint` method to provide a way to obtain `NetworkEndpoint` information of a connection via client identifier. (#3130)
 - Added `NetworkTransport.OnEarlyUpdate` and `NetworkTransport.OnPostLateUpdate` methods to provide more control over handling transport related events at the start and end of each frame. (#3113)
 
@@ -30,6 +31,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Changed
 
+- In-scene placed `NetworkObject`s have been made distributable when balancing object distribution after a connection event. (#3175)
 - Optimised `NetworkVariable` and `NetworkTransform` related packets when in Distributed Authority mode.
 - The Debug Simulator section of the Unity Transport component was removed. This section was not functional anymore and users are now recommended to use the more featureful [Network Simulator](https://docs-multiplayer.unity3d.com/tools/current/tools-network-simulator/) tool from the Multiplayer Tools package instead. (#3121)
 

com.unity.netcode.gameobjects/Editor/NetworkObjectEditor.cs

@@ -115,6 +115,10 @@ public override void OnInspectorGUI()
                 EditorGUI.BeginChangeCheck();
                 serializedObject.UpdateIfRequiredOrScript();
                 DrawPropertiesExcluding(serializedObject, k_HiddenFields);
+                if (m_NetworkObject.IsOwnershipSessionOwner)
+                {
+                    m_NetworkObject.Ownership = NetworkObject.OwnershipStatus.SessionOwner;
+                }
                 serializedObject.ApplyModifiedProperties();
                 EditorGUI.EndChangeCheck();
 
@@ -193,7 +197,7 @@ public override void OnGUI(Rect position, SerializedProperty property, GUIConten
 
             // The below can cause visual anomalies and/or throws an exception within the EditorGUI itself (index out of bounds of the array). and has
             // The visual anomaly is when you select one field it is set in the drop down but then the flags selection in the popup menu selects more items
-            // even though if you exit the popup menu the flag setting is correct. 
+            // even though if you exit the popup menu the flag setting is correct.
             //var ownership = (NetworkObject.OwnershipStatus)EditorGUI.EnumFlagsField(position, label, (NetworkObject.OwnershipStatus)property.enumValueFlag);
             //property.enumValueFlag = (int)ownership;
             EditorGUI.EndDisabledGroup();

com.unity.netcode.gameobjects/Runtime/Connection/NetworkConnectionManager.cs

@@ -11,7 +11,7 @@
 namespace Unity.Netcode
 {
     /// <summary>
-    /// The connection event type set within <see cref="ConnectionEventData"/> to signify the type of connection event notification received.   
+    /// The connection event type set within <see cref="ConnectionEventData"/> to signify the type of connection event notification received.
     /// </summary>
     /// <remarks>
     /// <see cref="ConnectionEventData"/> is returned as a parameter of the <see cref="NetworkManager.OnConnectionEvent"/> event notification.
@@ -1212,7 +1212,7 @@ internal void OnClientDisconnectFromServer(ulong clientId)
                                 {
                                     // Only NetworkObjects that have the OwnershipStatus.Distributable flag set and no parent
                                     // (ownership is transferred to all children) will have their ownership redistributed.
-                                    if (ownedObject.IsOwnershipDistributable && ownedObject.GetCachedParent() == null)
+                                    if (ownedObject.IsOwnershipDistributable && ownedObject.GetCachedParent() == null && !ownedObject.IsOwnershipSessionOwner)
                                     {
                                         if (ownedObject.IsOwnershipLocked)
                                         {
@@ -1249,6 +1249,11 @@ internal void OnClientDisconnectFromServer(ulong clientId)
                                                 childObject.SetOwnershipLock(false);
                                             }
 
+                                            // Ignore session owner marked objects
+                                            if (childObject.IsOwnershipSessionOwner)
+                                            {
+                                                continue;
+                                            }
                                             NetworkManager.SpawnManager.ChangeOwnership(childObject, targetOwner, true);
                                             if (EnableDistributeLogging)
                                             {

com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs

@@ -225,11 +225,7 @@ internal void SetSessionOwner(ulong sessionOwner)
                 foreach (var networkObjectEntry in SpawnManager.SpawnedObjects)
                 {
                     var networkObject = networkObjectEntry.Value;
-                    if (networkObject.IsSceneObject == null || !networkObject.IsSceneObject.Value)
-                    {
-                        continue;
-                    }
-                    if (networkObject.OwnerClientId != LocalClientId)
+                    if (networkObject.IsOwnershipSessionOwner && LocalClient.IsSessionOwner)
                     {
                         SpawnManager.ChangeOwnership(networkObject, LocalClientId, true);
                     }
@@ -416,7 +412,7 @@ public void NetworkUpdate(NetworkUpdateStage updateStage)
                         // Metrics update needs to be driven by NetworkConnectionManager's update to assure metrics are dispatched after the send queue is processed.
                         MetricsManager.UpdateMetrics();
 
-                        // Handle sending any pending transport messages 
+                        // Handle sending any pending transport messages
                         NetworkConfig.NetworkTransport.PostLateUpdate();
 
                         // TODO: Determine a better way to handle this

com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs

@@ -182,7 +182,7 @@ private static void PrefabStageOpened(PrefabStage prefabStage)
         /// <remarks>
         /// InContext: Typically means a are in prefab edit mode for an in-scene placed network prefab instance.
         /// (currently no such thing as a network prefab with nested network prefab instances)
-        /// 
+        ///
         /// InIsolation: Typically means we are in prefb edit mode for a prefab asset.
         /// </remarks>
         /// <param name="prefabStage"></param>
@@ -439,6 +439,13 @@ public void DeferDespawn(int tickOffset, bool destroy = true)
         /// </remarks>
         public bool IsOwnershipDistributable => Ownership.HasFlag(OwnershipStatus.Distributable);
 
+        /// <summary>
+        /// When true, the <see cref="NetworkObject"/> can only be owned by the current Session Owner.
+        /// To set <see cref="OwnershipStatus.SessionOwner"/> during runtime, use  <see cref="ChangeOwnership(ulong)"/> to ensure the session owner owns the object.
+        /// Once the session owner owns the object, then use <see cref="SetOwnershipStatus(OwnershipStatus, bool, OwnershipLockActions)"/>.
+        /// </summary>
+        public bool IsOwnershipSessionOwner => Ownership.HasFlag(OwnershipStatus.SessionOwner);
+
         /// <summary>
         /// Returns true if the <see cref="NetworkObject"/> is has ownership locked.
         /// When locked, the <see cref="NetworkObject"/> cannot be redistributed nor can it be transferred by another client.
@@ -481,7 +488,8 @@ public void DeferDespawn(int tickOffset, bool destroy = true)
         /// <see cref="None"/>: If nothing is set, then ownership is considered "static" and cannot be redistributed, requested, or transferred (i.e. a Player would have this).
         /// <see cref="Distributable"/>: When set, this instance will be automatically redistributed when a client joins (if not locked or no request is pending) or leaves.
         /// <see cref="Transferable"/>: When set, a non-owner can obtain ownership immediately (without requesting and as long as it is not locked).
-        /// <see cref="RequestRequired"/>: When set, When set, a non-owner must request ownership from the owner (will always get locked once ownership is transferred).
+        /// <see cref="RequestRequired"/>: When set, a non-owner must request ownership from the owner (will always get locked once ownership is transferred).
+        /// <see cref="SessionOwner"/>: When set, only the current session owner may have ownership over this object.
         /// </summary>
         // Ranges from 1 to 8 bits
         [Flags]
@@ -491,6 +499,7 @@ public enum OwnershipStatus
             Distributable = 1 << 0,
             Transferable = 1 << 1,
             RequestRequired = 1 << 2,
+            SessionOwner = 1 << 3,
         }
 
         /// <summary>
@@ -549,7 +558,7 @@ public bool SetOwnershipLock(bool lockOwnership = true)
             }
 
             // If we don't have the Transferable flag set and it is not a player object, then it is the same as having a static lock on ownership
-            if (!IsOwnershipTransferable && !IsPlayerObject)
+            if (!(IsOwnershipTransferable || IsPlayerObject) || IsOwnershipSessionOwner)
             {
                 NetworkLog.LogWarning($"Trying to add or remove ownership lock on [{name}] which does not have the {nameof(OwnershipStatus.Transferable)} flag set!");
                 return false;
@@ -582,13 +591,15 @@ public bool SetOwnershipLock(bool lockOwnership = true)
         /// <see cref="RequestRequired"/>: The <see cref="NetworkObject"/> requires an ownership request via <see cref="RequestOwnership"/>.
         /// <see cref="RequestInProgress"/>: The <see cref="NetworkObject"/> is already processing an ownership request and ownership cannot be acquired at this time.
         /// <see cref="NotTransferrable"/>: The <see cref="NetworkObject"/> does not have the <see cref="OwnershipStatus.Transferable"/> flag set and ownership cannot be acquired.
+        /// <see cref="SessionOwnerOnly"/>: The <see cref="NetworkObject"/> has the  <see cref="OwnershipStatus.SessionOwner"/> flag set and ownership cannot be acquired.
         /// </summary>
         public enum OwnershipPermissionsFailureStatus
         {
             Locked,
             RequestRequired,
             RequestInProgress,
-            NotTransferrable
+            NotTransferrable,
+            SessionOwnerOnly
         }
 
         /// <summary>
@@ -610,6 +621,7 @@ public enum OwnershipPermissionsFailureStatus
         /// <see cref="RequestRequiredNotSet"/>: The <see cref="OwnershipStatus.RequestRequired"/> flag is not set on this <see cref="NetworkObject"/>
         /// <see cref="Locked"/>: The current owner has locked ownership which means requests are not available at this time.
         /// <see cref="RequestInProgress"/>: There is already a known request in progress. You can scan for ownership changes and try upon
+        /// <see cref="SessionOwnerOnly"/>: This object is marked as SessionOwnerOnly and therefore cannot be requested
         /// a change in ownership or just try again after a specific period of time or no longer attempt to request ownership.
         /// </summary>
         public enum OwnershipRequestStatus
@@ -619,6 +631,7 @@ public enum OwnershipRequestStatus
             RequestRequiredNotSet,
             Locked,
             RequestInProgress,
+            SessionOwnerOnly,
         }
 
         /// <summary>
@@ -631,6 +644,7 @@ public enum OwnershipRequestStatus
         /// <see cref="OwnershipRequestStatus.RequestRequiredNotSet"/>: The <see cref="OwnershipStatus.RequestRequired"/> flag is not set on this <see cref="NetworkObject"/>
         /// <see cref="OwnershipRequestStatus.Locked"/>: The current owner has locked ownership which means requests are not available at this time.
         /// <see cref="OwnershipRequestStatus.RequestInProgress"/>: There is already a known request in progress. You can scan for ownership changes and try upon
+        /// <see cref="OwnershipRequestStatus.SessionOwnerOnly"/>: This object can only belong the the session owner and so cannot be requested
         /// a change in ownership or just try again after a specific period of time or no longer attempt to request ownership.
         /// </remarks>
         /// <returns><see cref="OwnershipRequestStatus"/></returns>
@@ -660,6 +674,12 @@ public OwnershipRequestStatus RequestOwnership()
                 return OwnershipRequestStatus.RequestInProgress;
             }
 
+            // Exit early if it has the SessionOwner flag
+            if (IsOwnershipSessionOwner)
+            {
+                return OwnershipRequestStatus.SessionOwnerOnly;
+            }
+
             // Otherwise, send the request ownership message
             var changeOwnership = new ChangeOwnershipMessage
             {
@@ -716,7 +736,7 @@ internal void OwnershipRequest(ulong clientRequestingOwnership)
             {
                 response = OwnershipRequestResponseStatus.RequestInProgress;
             }
-            else if (!IsOwnershipRequestRequired && !IsOwnershipTransferable)
+            else if (!(IsOwnershipRequestRequired || IsOwnershipTransferable) || IsOwnershipSessionOwner)
             {
                 response = OwnershipRequestResponseStatus.CannotRequest;
             }
@@ -836,6 +856,12 @@ public enum OwnershipLockActions
         /// </remarks>
         public bool SetOwnershipStatus(OwnershipStatus status, bool clearAndSet = false, OwnershipLockActions lockAction = OwnershipLockActions.None)
         {
+            if (status.HasFlag(OwnershipStatus.SessionOwner) && !NetworkManager.LocalClient.IsSessionOwner)
+            {
+                NetworkLog.LogWarning("Only the session owner is allowed to set the ownership status to session owner only.");
+                return false;
+            }
+
             // If it already has the flag do nothing
             if (!clearAndSet && Ownership.HasFlag(status))
             {
@@ -847,13 +873,25 @@ public bool SetOwnershipStatus(OwnershipStatus status, bool clearAndSet = false,
                 Ownership = OwnershipStatus.None;
             }
 
-            // Faster to just OR a None status than to check
-            // if it is !None before "OR'ing".
-            Ownership |= status;
-
-            if (lockAction != OwnershipLockActions.None)
+            if (status.HasFlag(OwnershipStatus.SessionOwner))
+            {
+                Ownership = OwnershipStatus.SessionOwner;
+            }
+            else if (Ownership.HasFlag(OwnershipStatus.SessionOwner))
+            {
+                NetworkLog.LogWarning("No other ownership statuses may be set while SessionOwner is set.");
+                return false;
+            }
+            else
             {
-                SetOwnershipLock(lockAction == OwnershipLockActions.SetAndLock);
+                // Faster to just OR a None status than to check
+                // if it is !None before "OR'ing".
+                Ownership |= status;
+
+                if (lockAction != OwnershipLockActions.None)
+                {
+                    SetOwnershipLock(lockAction == OwnershipLockActions.SetAndLock);
+                }
             }
 
             SendOwnershipStatusUpdate();
@@ -1629,7 +1667,7 @@ internal void SpawnInternal(bool destroyWithScene, ulong ownerClientId, bool pla
                     // DANGO-TODO: Review over don't destroy with owner being set but DistributeOwnership not being set
                     if (NetworkManager.LogLevel == LogLevel.Developer)
                     {
-                        NetworkLog.LogWarning("DANGO-TODO: Review over don't destroy with owner being set but DistributeOwnership not being set. For now, if the NetworkObject does not destroy with the owner it will automatically set DistributeOwnership.");
+                        NetworkLog.LogWarning("DANGO-TODO: Review over don't destroy with owner being set but DistributeOwnership not being set. For now, if the NetworkObject does not destroy with the owner it will set ownership to SessionOwner.");
                     }
                 }
             }