Resolved Problems with initial synchronization of NavMeshAgent with netcode.

I have the following PlayerController script attached to a NetworkObject to move a NavMeshAgernt towards a click in a multiplayer server authoritative game. The NetworkObject also has a NetworkTransform attached to it.

Code (CSharp):

1.  
2. using Unity.Netcode;
3. using UnityEngine;
4. using UnityEngine.AI;
5.  
6. public class PlayerController : NetworkBehaviour
7. {
8.     public LayerMask groundMask;
9.     public NavMeshAgent agent;
10.     public Camera camera;
11.  
12.     void Update()
13.     {
14.         if (!IsOwner) return;
15.         if (Input.GetMouseButtonDown(1))
16.         {
17.             Ray camMouseRay = camera.ScreenPointToRay(Input.mousePosition);
18.             RaycastHit hitInfo;
19.             if (Physics.Raycast(camMouseRay, out hitInfo, 100, groundMask))
20.             {
21.                 SetAgentDestinationServerRpc(hitInfo.point);
22.             }
23.         }
24.     }
25.  
26.     [ServerRpc]
27.     public void SetAgentDestinationServerRpc(Vector3 destination)
28.     {
29.         agent.destination = destination;
30.     }
31. }
32.  

The code seems to work fine except when a new client joins, the position of old clients and hosts is not immediatley syncronized, only when the other clients make their first move do you see any movement in the new client (which then seems to be synchronized). Regardless of whether the old clients move or not, the new one does appear synchronized from the start on both the old clients and host.

Am I doing something wrong? Or is this expected behaviour? If so how can i modify the code to update all agents positions on load.

 

Hello Riku, thanks for your response and taking the time to help me out.

I meant the second option, the position of old clients and hosts is not synchronized on the new client's game instance, but only at the very start, once new movements come in they synchronize.

I tried both of the suggestions;
1. The first suggestion I tried by removing the navmeshagent component on non server instances, but this did nothing, the final product was still behaving the same (Synching everything except existing network transforms initial positions at the start of a new client joining)
2. I am not familiar with syncvars but after looking into it a bit it seems like its from the Mirror Library and as far as i could tell using NetworkVariables is the same, please correct me if im wrong. Using Network variables i managed to fix the issue, the code looks like this:

Code (CSharp):

1.  
2. using Unity.Netcode;
3. using UnityEngine;
4. using UnityEngine.AI;
5.  
6. public class PlayerController : NetworkBehaviour
7. {
8.     public LayerMask groundMask;
9.     public NavMeshAgent agent;
10.     public Camera camera;
11.  
12.     public NetworkVariable<Vector3> _destination = new(writePerm: NetworkVariableWritePermission.Server);
13.  
14.     public override void OnNetworkSpawn()
15.     {
16.         if (!IsServer & !IsHost)
17.             Destroy(agent.GetComponent<NavMeshAgent>());
18.         if(IsClient)
19.             agent.transform.position = _destination.Value;
20.     }
21.  
22.     void Update()
23.     {
24.         if (!IsOwner) return;
25.         if (Input.GetMouseButtonDown(1))
26.         {
27.             Ray camMouseRay = camera.ScreenPointToRay(Input.mousePosition);
28.             RaycastHit hitInfo;
29.             if (Physics.Raycast(camMouseRay, out hitInfo, 100, groundMask))
30.             {
31.                 SetAgentDestinationServerRpc(hitInfo.point);
32.             }
33.         }
34.     }
35.  
36.     [ServerRpc]
37.     public void SetAgentDestinationServerRpc(Vector3 destination)
38.     {
39.         agent.destination = destination;
40.         _destination.Value = destination;
41.     }
42. }
43.  

Now this seems to work, but this leaves me with 2 questions:
1. If i have hundreds of network objects, wont adding a network variable to it make the network load much bigger? Specially since the only real use is for when a new player joins.
2. As i mentioned before, maybe i completely misunderstood and this isnt the approach you meant, and i do need to use the mirror library with the syncvar.
Thanks for any clarification in advance.

 

Thanks again Raiku for all the help.
Yes, im developing a MOBA-RTS, which is why im imagining quite a bit of unit controlls, closer to a total war game, ill take a look at the link you provided since it seems like a good read.

The way I implemented it it would be changing every click which could be a lot, I guess I can continue with development since there doesnt seemsto be a bottleneck so far, i just wanted to get my foundations right before proceeding.

I agree, in fact i was gonna use a custom struct, but i just simplified the code for the question.

 

Hello, I had the same problem and I managed to solve it, but I use unity 2022 and so that it did not give me an error, I had to use the old version, the navigation which is obsolete because with NavMeshsurf it did not solve it