Question "Don't know how to serialize List`1 " When using NetworkList

Hello, sorry if this is a simple one, but I'm completely new to NetCode for GameObjects and lost.
I am attempting to use a NetworkList as I need to transmit a series of 52 or more floats. However I am receiving compile errors that occur in the Rpc function.
"Assets\Scripts\AVNetworkController.cs(116,14): error - Don't know how to deserialize List`1 - implement INetworkSerializable or add an extension method for FastBufferReader.ReadValueSafe to define serialization."

Here is a snippet of the code:

Code (CSharp):

1.  
2. [SerializeField]
3. public NetworkList<float> NetworkFKList;
4.  
5. private void Start()
6.    {
7.       NetworkFKList = new NetworkList<float>();
8.       for (int i = 0; i < 52; i++)
9.          {
10.             NetworkFKList.Add(0f);
11.          }
12. //Somewhere in here newFKList is populated with values I need that I am attempting to transfer to NetworkFKList
13. [ServerRpc]
14. public void UpdateFaceKeysServerRpc(List<float> newFKList)
15.     {
16.         for (int i = 0; i < newFKList.Count; i++)
17.         {
18.             NetworkFKList[i] = newFKList[i];
19.            // I have also tried NetworkFKList.Add(newFKList[i]);
20.         }
21.     }

Am I using NetworkLists wrong?, is this not their purpose?

 

The error isn't related to NetworkList but trying to pass a list to the server RPC. You can pass arrays so use an array of floats at this point instead of a list.

 

Sweet that worked!. Thanks

Code (CSharp):

1.     [ServerRpc]
2.     public void UpdateFaceKeysServerRpc(float[] sentFKArray)
3.     {
4.  
5.         for (int i = 0; i < 52; i++)
6.         {
7.             NetworkFKList[i] = sentFKArray[i];
8.         }
9.     }

The only issue I'm running into now is a buffer size limit, looks like I'm exceeding it.
But it looks like there are a few threads from people experiencing similar issues so I'll look there.

 

Update Netcode to pre.4 if you haven't already, it fixes a bug where you quickly reached a limit of how much you could add to a NetworkList.

 

I am currently using pre.4

Should this not normally be happening using the NetworkList?
I just assumed I was sending too much data and there was a way to increase the limit somehow. I haven't had a chance to attempt that yet.

 

Here's an example of the kind of floats I'm sending. It's OSC data from IOS ARKit face tracking. I'm converting it to a list in order to send it over a multiplayer game. These 52 values update 30 times a second (running project at 30fps)

Code (CSharp):

1. 0.1011367216706276
2. 0.29201051592826843
3. 0.2936050593852997
4. 0.0
5. 0.0
6. 0.11452288180589676
7. 0.11481111496686935
8. -0.6710376143455505
9. -0.6677505373954773
10. 0.139095738530159
11. -0.14511656761169434
12. -0.008100325241684914
13. 0.026931222528219223
14. -0.061308275908231735
15. -0.06132631376385689
16. 0.15053518116474152
17. 0.1505589783191681
18. 0.3570777475833893
19. 0.3565797209739685
20. 0.010035885497927666
21. 0.025939203798770905
22. 0.035172563046216965
23. -0.02708432264626026
24. -0.03149525076150894
25. -0.003989010583609343
26. -0.027976475656032562
27. 0.025100162252783775
28. -0.0005838338402099907
29. 0.04119766131043434
30. 0.07112914323806763
31. -0.011954116635024548
32. 0.0
33. -0.02208051085472107
34. -0.04752753674983978
35. 0.005517500452697277
36. -0.008611667901277542
37. 0.008307084441184998
38. -0.17919869720935822
39. -0.15959085524082184
40. 0.041160061955451965
41. 0.023376038298010826
42. -0.02457955665886402
43. -0.023629918694496155
44. -0.013307630084455013
45. -0.010534528642892838
46. -0.035656966269016266
47. -0.03259516879916191
48. -0.010734405368566513
49. -0.009134470485150814
50. 0.008960368111729622
51. -0.0008349923882633448
52. -1.0189183541342572e-07

 

I wouldn't have expected to hit a limit with that amount of data. Are you clearing the list each time or is it accumulative? I'll have to try it out myself.

 

Hmm, I did make a mistake. I was adding the 52 floats twice
But I've fixed this and the errors still exists. I added a quick Debug.Log to check the lengths / counts as well as the values themselves to ensure they're remaining at 52 and the values are there.

Code (CSharp):

1.     public void UpdateFaceKeysServerRpc(float[] sentFKArray)
2.     {
3.  
4.         for (int i = 0; i < sentFKArray.Length; i++)
5.         {
6.             NetworkFKList[i] = sentFKArray[i];
7.         }
8.  
9.  
10.         Debug.Log("NEW ARRAY, Length = " + sentFKArray.Length);
11.         for (int i = 0; i < sentFKArray.Length; i++)
12.         {
13.             Debug.Log(sentFKArray[i]);
14.         }
15.  
16.  
17.         Debug.Log("NEW NETWORKLIST, Length = " + NetworkFKList.Count);
18.         for (int i = 0; i < NetworkFKList.Count; i++)
19.         {
20.             Debug.Log(NetworkFKList[i]);
21.         }
22.     }

Code (CSharp):

1. NEW NETWORKLIST, Length = 52
2. -0.09315924
3. 0.2538644
4. 0.2538856
5. 0
6. 0
7. 0
8. 0
9. -0.6203992
10. -0.6172931
11. 0.1109501
12. -0.1417809
13. -0.008100325
14. 0
15. -0.06130828
16. -0.06132631
17. 0.09946179
18. 0.0994793
19. 0.2214654
20. 0.2214648
21. 0.06251084
22. 0.02068622
23. 0.01802551
24. -0.008629035
25. 0.0007583712
26. -0.015517
27. -0.02099421
28. 0
29. 0.007778692
30. 0.1041044
31. 0.3380764
32. -0.0006523338
33. 0
34. -0.02800294
35. -0.05935419
36. 0.05316978
37. 0.05798394
38. 0.003470858
39. -0.1791987
40. -0.1595909
41. 0.1008237
42. 0.1104052
43. -0.0311375
44. -0.03060791
45. -0.008074892
46. -0.005112974
47. -0.04285654
48. -0.04221743
49. 0.02626065
50. 0.02309331
51. 0.01022728
52. 0.001209655
53. -1.281316E-07
54. NEW ARRAY, Length = 52
55. -0.09315924
56. 0.2538644
57. 0.2538856
58. 0
59. 0
60. 0
61. 0
62. -0.6203992
63. -0.6172931
64. 0.1109501
65. -0.1417809
66. -0.008100325
67. 0
68. -0.06130828
69. -0.06132631
70. 0.09946179
71. 0.0994793
72. 0.2214654
73. 0.2214648
74. 0.06251084
75. 0.02068622
76. 0.01802551
77. -0.008629035
78. 0.0007583712
79. -0.015517
80. -0.02099421
81. 0
82. 0.007778692
83. 0.1041044
84. 0.3380764
85. -0.0006523338
86. 0
87. -0.02800294
88. -0.05935419
89. 0.05316978
90. 0.05798394
91. 0.003470858
92. -0.1791987
93. -0.1595909
94. 0.1008237
95. 0.1104052
96. -0.0311375
97. -0.03060791
98. -0.008074892
99. -0.005112974
100. -0.04285654
101. -0.04221743
102. 0.02626065
103. 0.02309331
104. 0.01022728
105. 0.001209655
106. -1.281316E-07

Maybe I can throw together something generic for testing.

 

I was able to add 200 floats but with 300 I got the same error. I tried UNet and Unity transports with various settings but with no difference so I guess the buffer is handled higher up. Have you got any other network traffic going on at the same time, in case that's eating into the same buffer.

 

The initial OSC values are sent over my network (either over WiFi or Lan).
But I've turned that off and just replaced my current setup with a generic component that I can run without all that stuff and I still get the error.
I'm not sure what the best way to send component is but here it is. It just gets attached to the Player prefab (+ a Network Controller) that gets spawned from the built in Network Manager

Code (CSharp):

1. using Unity.Netcode;
2. using UnityEngine;
3.  
4. public class NetworkListTester : NetworkBehaviour
5. {
6.     [SerializeField]
7.     public NetworkList<float> NetworkFKList;
8.     public float[] FKArray = new float[52];
9.     // Start is called before the first frame update
10.  
11.     private void Awake()
12.     {
13.     }
14.     private void Start()
15.     {
16.         if (IsServer)
17.         {
18.         }
19.         if (IsClient && IsOwner)
20.         {
21.             //Populating array and NetworkList with 52 0f values
22.             for (int i = 0; i < 52; i++)
23.             {
24.                 FKArray[i] = (0);
25.                 NetworkFKList.Add(0f);
26.             }
27.         }
28.     }
29.     private void UpdateServer()
30.     {
31.     }
32.     private void UpdateClient()
33.     {
34.         for (int i = 0; i < FKArray.Length; i++)
35.         {   //Normally this sets values in FKArray to the /W OSC values in the facekey dictionary
36.             //Just using a float that you would typically see from OSC ARKit face tracking
37.             FKArray[i] = -0.0006523338f;
38.         }
39.         UpdateFaceKeysServerRpc(FKArray);
40.     }
41.  
42.     // Update is called once per frame
43.     private void Update()
44.     {
45.         if (IsServer)
46.         {
47.             UpdateServer();
48.         }
49.         if (IsClient && IsOwner)
50.         {
51.             UpdateClient();
52.         }
53.     }
54.  
55.     [ServerRpc]
56.     public void UpdateFaceKeysServerRpc(float[] sentFKArray)
57.     {
58.  
59.         for (int i = 0; i < sentFKArray.Length; i++)
60.         {
61.             NetworkFKList[i] = sentFKArray[i];
62.         }
63.  
64.         //---Debug.Logs to ensure Array and Network list have 52 floats---
65.  
66.         Debug.Log("NEW ARRAY, Lenth = " + sentFKArray.Length);
67.         //---Log each value---
68.         //for (int i = 0; i < sentFKArray.Length; i++)
69.         //{
70.         //    Debug.Log(sentFKArray[i]);
71.         //}
72.         //
73.         Debug.Log("NEW NETWORKLIST, Lenth = " + NetworkFKList.Count);
74.         //---Log each value---
75.         //for (int i = 0; i < NetworkFKList.Count; i++)
76.         //{
77.         //    Debug.Log(NetworkFKList[i]);
78.         //}
79.     }
80. }
81.  

There's a good chance I'm just doing something totally wrong though. Thanks for the help so far.

 

And just to be sure, here's the error code:

Code (CSharp):

1. OverflowException: Writing past the end of the buffer
2. Unity.Netcode.NetworkList`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/NetworkVariable/Collections/NetworkList.cs:125)
3. Unity.Netcode.NetworkVariableDeltaMessage.Serialize (Unity.Netcode.FastBufferWriter writer) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Messaging/Messages/NetworkVariableDeltaMessage.cs:77)
4. Unity.Netcode.NetworkBehaviour.NetworkVariableUpdate (System.UInt64 clientId, System.Int32 behaviourIndex) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkBehaviour.cs:548)
5. Unity.Netcode.NetworkBehaviour.VariableUpdate (System.UInt64 clientId) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkBehaviour.cs:494)
6. Unity.Netcode.NetworkBehaviourUpdater.NetworkBehaviourUpdate (Unity.Netcode.NetworkManager networkManager) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkBehaviourUpdater.cs:36)
7. Unity.Netcode.NetworkManager.OnNetworkManagerTick () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkManager.cs:1241)
8. Unity.Netcode.NetworkTickSystem.UpdateTick (System.Double localTimeSec, System.Double serverTimeSec) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Timing/NetworkTickSystem.cs:96)
9. Unity.Netcode.NetworkManager.OnNetworkPreUpdate () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkManager.cs:1208)
10. Unity.Netcode.NetworkManager.NetworkUpdate (Unity.Netcode.NetworkUpdateStage updateStage) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkManager.cs:1155)
11. Unity.Netcode.NetworkUpdateLoop.RunNetworkUpdateStage (Unity.Netcode.NetworkUpdateStage updateStage) (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkUpdateLoop.cs:149)
12. Unity.Netcode.NetworkUpdateLoop+NetworkPreUpdate+<>c.<CreateLoopSystem>b__0_0 () (at Library/PackageCache/com.unity.netcode.gameobjects@1.0.0-pre.4/Runtime/Core/NetworkUpdateLoop.cs:196)
13.  

 

You could try slowing down the rate at which you're sending the updates to the server to see if it makes a difference, in case the server is accumulating those updates then making multiple update changes to the list at once. I don't know how this governed though, I assume by the server tick rate.

 

Ok did some testing. I didn't exactly fix it but...Increasing my Tick Rate to 120 seems to fix it

That may have been what you meant with "You could try slowing down the rate".
I just didn't even try going higher because I assumed that would make the issue worse.
I guess it all accumulates if it cant all be sent in 1 frame/tick and if you don't get it out fast enough you overflow the buffer? I don't understand half of this but that's my guess.
I'm using the U Net Transport and it didn't matter how large I made my buffer or queue size or tried Immediately or Queued mode it would overflow.
I don't know what the implications are of having my tick rate so high (maybe network saturation)? But I'm just gonna go with it until things are a little more clear.

Going to 60 even works. I set it to 30 originally because I assumed matching tick rate and frame rate was ideal? (My project is locked at 30)

 

Ok I messed up, super stupid oversight - turns out my frame limit was disabled and I was running uncapped around 120fps with tick rate at 30.

So I guess if the tick rate is lower than the frame rate it can cause overflow with enough floats in a list?
Setting FPS to 30 with Tick Rate of 30 is fine now. But I might set it higher for safety.

 

I'm assuming that's the case, glad you got it sorted anyway. There's meant to be a fix coming allowing for custom buffer sizes which I hope will mean an end to this issue. You'll just need to switch over to the Unity Transport.