fix: NetworkAnimator generating AnimationCurve warnings (#2416)

* fix
Don't try to access m_Animator if it is not assigned.
Don't try to update animation curves.
Now generate a tracking list for all parameters and cull out those controlled by AnimationCurves when checking for deltas.

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -15,6 +15,8 @@ Additional documentation and release notes are available at [Multiplayer Documen
 ### Fixed
 
 - Fixed registry of public `NetworkVariable`s in derived `NetworkBehaviour`s (#2423)
+- Fixed issue where runtime association of `Animator` properties to `AnimationCurve`s would cause `NetworkAnimator` to attempt to update those changes. (#2416)
+- Fixed issue where `NetworkAnimator` would not check if its associated `Animator` was valid during serialization and would spam exceptions in the editor console. (#2416)
 
 ### Removed
 

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

@@ -279,6 +279,11 @@ namespace Unity.Netcode.Components
             {
                 return;
             }
+            if (m_Animator == null)
+            {
+                return;
+            }
+
             TransitionStateInfoList = new List<TransitionStateinfo>();
             var animatorController = m_Animator.runtimeAnimatorController as AnimatorController;
             if (animatorController == null)
@@ -588,17 +593,13 @@ namespace Unity.Netcode.Components
             m_CachedAnimatorParameters = new NativeArray<AnimatorParamCache>(parameters.Length, Allocator.Persistent);
             m_ParametersToUpdate = new List<int>(parameters.Length);
 
+            // Include all parameters including any controlled by an AnimationCurve as this could change during runtime.
+            // We ignore changes to any parameter controlled by an AnimationCurve when we are checking for changes in
+            // the Animator's parameters.
             for (var i = 0; i < parameters.Length; i++)
             {
                 var parameter = parameters[i];
 
-                if (m_Animator.IsParameterControlledByCurve(parameter.nameHash))
-                {
-                    // we are ignoring parameters that are controlled by animation curves - syncing the layer
-                    //  states indirectly syncs the values that are driven by the animation curves
-                    continue;
-                }
-
                 var cacheParam = new AnimatorParamCache
                 {
                     Type = UnsafeUtility.EnumToInt(parameter.type),
@@ -643,6 +644,12 @@ namespace Unity.Netcode.Components
         /// <inheritdoc/>
         public override void OnNetworkSpawn()
         {
+            // If there is no assigned Animator then generate a server network warning (logged locally and if applicable on the server-host side as well).
+            if (m_Animator == null)
+            {
+                NetworkLog.LogWarningServer($"[{gameObject.name}][{nameof(NetworkAnimator)}] {nameof(Animator)} is not assigned! Animation synchronization will not work for this instance!");
+            }
+
             if (IsServer)
             {
                 m_ClientSendList = new List<ulong>(128);
@@ -906,6 +913,14 @@ namespace Unity.Netcode.Components
             for (int i = 0; i < m_CachedAnimatorParameters.Length; i++)
             {
                 ref var cacheValue = ref UnsafeUtility.ArrayElementAsRef<AnimatorParamCache>(m_CachedAnimatorParameters.GetUnsafePtr(), i);
+
+                // If a parameter gets controlled by a curve during runtime after initialization of NetworkAnimator
+                // then ignore changes to this parameter. We are not removing the parameter in the event that
+                // it no longer is controlled by a curve.
+                if (m_Animator.IsParameterControlledByCurve(cacheValue.Hash))
+                {
+                    continue;
+                }
                 var hash = cacheValue.Hash;
                 if (cacheValue.Type == AnimationParamEnumWrapper.AnimatorControllerParameterInt)
                 {