Server game object hierarchy is not the same as client game object hierarchy

Unity Engine
1

Spawning game objects across the network is flaky, as I see it.

On the server, the object hierarchy is far more “different” than on the client side. As you can see, I spawn them in a nested way on the server, however, the client does not correspond to the nested spawning, and thus creates a different layout.

1920×1160 117 KB

How do you organize them, so it is consistent on both the clients and the server? I tried prefabs, but they only work when game objects are inside a prefab. Multiple prefabs will break the layout.

I found out this the hard way. Now my project is close to a deadline, and my “severe Unity design flaw” stems out like this. I blame myself for not seeing this before when I had the chance, but I really wanted to fix this.

I wanted both the clients and the server to have consistent hierarchy when “spawning” the NetworkManager registered prefabs.

It’s frustrating to see this happening…

2

I had the same problem with my project, but it was happening the following:
On host:

  • Player1
    –Object1
  • Player2
    –Object2

And on client:
-Player1
-Object1
-Player2
–Object2

So on the host it was not being set in the correct position. One easy and fast way i’ve found to fix this was to create a StartCoroutine and wait for 5 seconds before initializing any object.

Can you post how you spawning this? Or these are just the player prefabs?

3

Yeah. We need to see more. It looks like you spawning things as children on the server, but not on the client. The only way I know this is possible, is if you Instantiate, then NetworkServer.Spawn …and then on the server make changes to the objects parentage.

4

Sorry about that. When I posted this thread, I was mad, and sleepy at 4AM.

This is the code I used for the test project:

using UnityEngine;
using UnityEngine.Networking;
using System.Collections;

public class CubeTest : NetworkBehaviour {
    public GameObject spawnParent;
    public GameObject unitUmbrella;

    // Use this for initialization
    void Start () {
     
    }
 
    // Update is called once per frame
    void Update () {
        if (Input.GetKeyUp(KeyCode.S)) {
            CmdTest();
        }
    }

    [ServerCallback]
    public void ServerStuff() {
        GameObject obj = MonoBehaviour.Instantiate(this.spawnParent) as GameObject;
        obj.transform.position = new Vector3(Random.Range(-10f, 30f), Random.Range(-10f, 30f), Random.Range(-10f, 30f));
        obj.transform.SetParent(unitUmbrella.transform);
        NetworkServer.SpawnWithClientAuthority(obj, this.connectionToClient);
        RpcTest();
    }

    [ClientCallback]
    public void ClientStuff() {
    }

    [ClientRpc]
    public void RpcTest() {
        if (!isLocalPlayer) {
            return;
        }

        Debug.Log("TEST>");
    }

    [Command]
    public void CmdTest() {
        ServerStuff();
    }
}

When you mentioned “…Instantiating the object, then NetworkServer.Spawn()…”, do they actually keep the hierarchy relations with one another? I kept experimenting to see if I can just spawn in with prefabs of similar hierarchical relations, and they sort of do. You can spawn in only up to 2 tiers in total, but you can’t spawn more than 2 tiers.

Can do this on the client when doing the same on the server:

  • Tier 1

  • Tier 2

  • Tier 1

  • Tier 2

Can’t do this on the client when doing the same on the server:

  • Tier 1

  • Tier 2

  • Tier 1

  • Tier 2

  • Tier 1

  • Tier 2

I don’t know if I’m doing it right through scripting. All I know is that I was mad because it severely broke and crippled my multiplayer game. :frowning: Probably never going to use GetComponentInChildren()…

5

I guess you need to do a clientRCP like the following (Adjusting to your hierarch)

[ClientRpc] //Server calls client
void RpcSetParent(GameObject instance)
{
instance.transform.parent = transform;
}

Call this one after obj.transform.setParent()

Tell me if it worked

6

I’ll go ahead and try. Once I know it’s working, I’ll come back and update.