NetworkObject

Netcode for Gameobjects' high level components, the RPC system and the Object Spawning System, rely on two concepts: NetworkObjects and NetworkBehaviours.

note

GameObjects, NetworkObjects and NetworkBehaviour are not serializable types so they cannot be used in RPCs or NetworkVariables by default. For infromation on how to send a reference to a NetworkObject over RPCs or NetworkVariables see NetworkObject &NetworkBehaviour.

NetworkObject

For an object to be replicated across the network, it needs to have a NetworkObject component. Each object which uses components networking functionality, like NetworkTransform or NetworkBehaviours with NetworkVariables or RPCs, needs a NetworkObject component on the same GameObject or in a parent.

When a NetworkObject is considered "Spawned", it is replicated across the network so that everyone has their own version of the object. Each NetworkObject gets assigned a NetworkId at runtime, which is used to associate two NetworkObjects across the network. For example, one peer can say "Send this RPC to the object with the NetworkId 103", and everyone knows what object that is.

To add custom code logic to your NetworkObjects, use NetworkBehaviours.

Ownership

Each NetworkObject is owned by a specific client. This can be any client of the server.

Give ownership of an object using the following:

GetComponent<NetworkObject>().ChangeOwnership(clientId);

The default behavior is that an object is owned by the client. To give ownership back to the server, you can use the RemoveOwnership call:

GetComponent<NetworkObject>().RemoveOwnership();

When you are owner of an object, you can check for IsOwner in any NetworkBehaviour, similar to how player objects can do IsLocalPlayer.

Player Objects

Player objects are an optional feature in Netcode which can be used to assign a networked object to a specific client. A client can always only have at most one player object.

If you want a client to control multiple objects use the ownership model instead.

Creating a Player Object

Netcode can spawn a default player object for you. If Create Player Prefab is activated in the NetworkManager, then Netcode will spawn the prefab marked as Default Player Prefab in the NetworkPrefabs list for each client upon connection.

To manually spawn an object as player object, use SpawnAsPlayerObject instead of the regular Spawn method. This replaces the old player object with the new one.

note

The old object will still exist and will be an object owned by the client instead.

Finding Player Objects

To find a player object for a specific client id you can use the following:

NetworkManager.Singleton.ConnectedClients[clientId].PlayerObject;

To find your own player object just pass NetworkManager.Singleton.LocalClientId as the clientId in the sample above.