Question Questions Regarding MLAPI Code

Code (CSharp):

1.  
2. using MLAPI;
3. using MLAPI.Messaging;
4. using MLAPI.NetworkVariable;
5. using UnityEngine;
6.  
7. namespace HelloWorld
8. {
9.     public class HelloWorldPlayer : NetworkBehaviour
10.     {
11.         public NetworkVariableVector3 Position = new NetworkVariableVector3(new NetworkVariableSettings
12.         {
13.             WritePermission = NetworkVariablePermission.ServerOnly,
14.             ReadPermission = NetworkVariablePermission.Everyone
15.         });
16.  
17.         public override void NetworkStart()
18.         {
19.             Move();
20.         }
21.  
22.         public void Move()
23.         {
24.             if (NetworkManager.Singleton.IsServer)
25.             {
26.                 var randomPosition = GetRandomPositionOnPlane();
27.                 transform.position = randomPosition;
28.                 Position.Value = randomPosition;
29.             }
30.             else
31.             {
32.                 SubmitPositionRequestServerRpc();
33.             }
34.         }
35.  
36.         [ServerRpc]
37.         void SubmitPositionRequestServerRpc(ServerRpcParams rpcParams = default)
38.         {
39.             Position.Value = GetRandomPositionOnPlane();
40.         }
41.  
42.         static Vector3 GetRandomPositionOnPlane()
43.         {
44.             return new Vector3(Random.Range(-3f, 3f), 1f, Random.Range(-3f, 3f));
45.         }
46.  
47.         void Update()
48.         {
49.             transform.position = Position.Value;
50.         }
51.     }
52. }

I am quite new to Unity and recently just started using MLAPI. Can I know why do we need to put (ServerRpcParams rpcParams = default)? What function does it have? And what happens if we dont put it in? I read the documentation but my understanding of it is still cloudy at best

Code (CSharp):

1.       [ServerRpc]
2.         void SubmitPositionRequestServerRpc(ServerRpcParams rpcParams = default)
3.         {
4.             Position.Value = GetRandomPositionOnPlane();
5.         }

Any help is greatly appreciated!

 

There is no need to include `ServerRpcParams` if you don't use it. One use case of the `ServerRpcParams` is to get access to the sender client of the RPC (rpcParams.Receive.SenderClientId`.

 

Thanks for the explanation luke. Also if you dont mind, can you also give an example on a time where we would need to get access to the sender client of the RPC?

 

And also, for this section for the code,

Code (CSharp):

1. public override void NetworkStart()
2.         {
3.             Move();
4.         }

is it really neccessary to override? And what are we overriding?

 

NetworkStart gets called whenever a NetworkObject gets spawned. The base function is just empty so you are not overriding any existing behavior. You can think of it as something like `Awake` or `Start` it just uses a different syntax.

 

For instance if you have an object in the scene with which any player can interact with. Let's say a button which they can press and if they do so a text changes to their name. probably not the best example but whatever . In that case you could use a ServerRPC to send that button press up and you would use the owner id to figure out which player pressed.