fix: NetworkTransform dropped packets can cause interpolation stutter [MTT-7551]

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -14,8 +14,12 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 - Fixed a bug where having a class with Rpcs that inherits from a class without Rpcs that inherits from NetworkVariable would cause a compile error. (#2751)
 - Fixed issue where `NetworkBehaviour.Synchronize` was not truncating the write buffer if nothing was serialized during `NetworkBehaviour.OnSynchronize` causing an additional 6 bytes to be written per `NetworkBehaviour` component instance. (#2749)
+- Fixed issue where a parented in-scene placed NetworkObject would be destroyed upon a client or server exiting a network session but not unloading the original scene in which the NetworkObject was placed. (#2737)
+- Fixed issue where during client synchronization and scene loading, when client synchronization or the scene loading mode are set to `LoadSceneMode.Single`, a `CreateObjectMessage` could be received, processed, and the resultant spawned `NetworkObject` could be instantiated in the client's currently active scene that could, towards the end of the client synchronization or loading process, be unloaded and cause the newly created `NetworkObject` to be destroyed (and throw and exception). (#2735)
+- Fixed issue where a `NetworkTransform` instance with interpolation enabled would result in wide visual motion gaps (stuttering) under above normal latency conditions and a 1-5% or higher packet are drop rate. (#2713)
 
 ### Changed
+- Changed `NetworkTransform` authoritative instance tick registration so a single `NetworkTransform` specific tick event update will update all authoritative instances to improve perofmance. (#2713)
 
 ## [1.7.0] - 2023-10-11
 

com.unity.netcode.gameobjects/Components/NetworkDeltaPosition.cs

@@ -23,12 +23,20 @@ public struct NetworkDeltaPosition : INetworkSerializable
         internal Vector3 DeltaPosition;
         internal int NetworkTick;
 
+        internal bool SynchronizeBase;
+
+        internal bool CollapsedDeltaIntoBase;
+
         /// <summary>
         /// The serialization implementation of <see cref="INetworkSerializable"/>
         /// </summary>
         public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
         {
             HalfVector3.NetworkSerialize(serializer);
+            if (SynchronizeBase)
+            {
+                serializer.SerializeValue(ref CurrentBasePosition);
+            }
         }
 
         /// <summary>
@@ -122,6 +130,7 @@ public Vector3 GetDeltaPosition()
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void UpdateFrom(ref Vector3 vector3, int networkTick)
         {
+            CollapsedDeltaIntoBase = false;
             NetworkTick = networkTick;
             DeltaPosition = (vector3 + PrecisionLossDelta) - CurrentBasePosition;
             for (int i = 0; i < HalfVector3.Length; i++)
@@ -136,6 +145,7 @@ public void UpdateFrom(ref Vector3 vector3, int networkTick)
                         CurrentBasePosition[i] += HalfDeltaConvertedBack[i];
                         HalfDeltaConvertedBack[i] = 0.0f;
                         DeltaPosition[i] = 0.0f;
+                        CollapsedDeltaIntoBase = true;
                     }
                 }
             }
@@ -164,6 +174,8 @@ public NetworkDeltaPosition(Vector3 vector3, int networkTick, bool3 axisToSynchr
             DeltaPosition = Vector3.zero;
             HalfDeltaConvertedBack = Vector3.zero;
             HalfVector3 = new HalfVector3(vector3, axisToSynchronize);
+            SynchronizeBase = false;
+            CollapsedDeltaIntoBase = false;
             UpdateFrom(ref vector3, networkTick);
         }
 

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

@@ -10,6 +10,7 @@ namespace Unity.Netcode.Editor
     [CustomEditor(typeof(NetworkTransform), true)]
     public class NetworkTransformEditor : UnityEditor.Editor
     {
+        private SerializedProperty m_UseUnreliableDeltas;
         private SerializedProperty m_SyncPositionXProperty;
         private SerializedProperty m_SyncPositionYProperty;
         private SerializedProperty m_SyncPositionZProperty;
@@ -39,6 +40,7 @@ public class NetworkTransformEditor : UnityEditor.Editor
         /// <inheritdoc/>
         public void OnEnable()
         {
+            m_UseUnreliableDeltas = serializedObject.FindProperty(nameof(NetworkTransform.UseUnreliableDeltas));
             m_SyncPositionXProperty = serializedObject.FindProperty(nameof(NetworkTransform.SyncPositionX));
             m_SyncPositionYProperty = serializedObject.FindProperty(nameof(NetworkTransform.SyncPositionY));
             m_SyncPositionZProperty = serializedObject.FindProperty(nameof(NetworkTransform.SyncPositionZ));
@@ -129,7 +131,9 @@ public override void OnInspectorGUI()
             EditorGUILayout.PropertyField(m_PositionThresholdProperty);
             EditorGUILayout.PropertyField(m_RotAngleThresholdProperty);
             EditorGUILayout.PropertyField(m_ScaleThresholdProperty);
-
+            EditorGUILayout.Space();
+            EditorGUILayout.LabelField("Delivery", EditorStyles.boldLabel);
+            EditorGUILayout.PropertyField(m_UseUnreliableDeltas);
             EditorGUILayout.Space();
             EditorGUILayout.LabelField("Configurations", EditorStyles.boldLabel);
             EditorGUILayout.PropertyField(m_InLocalSpaceProperty);