How to Set Up Multiplayer in Unity

Edited 1 day ago by ExtremeHow Editorial Team

UnityMultiplayerNetworkingGame DevelopmentOnlineLANScriptingC#ServerClientPhotonMirrorWindowsMacLinux

Unity is one of the most popular platforms for developing video games, and setting up multiplayer functionality can enhance the gaming experience by allowing players to interact with each other. In this detailed guide, we'll go over how to set up multiplayer in Unity, covering everything you need to know from start to finish. This guide is intended for beginner and intermediate Unity developers who are new to multiplayer game setup.

Introducing multiplayer in Unity

Multiplayer games allow multiple players to interact and play in the same game environment, whether they are on the same device or connected to the Internet. When setting up multiplayer in Unity, we need to understand the necessary basic components such as networking, synchronization, and player communication.

Choosing the right networking solution

Before you begin, it's important to choose a networking solution that best suits your project. Unity offers several options for networking, each with its own merits:

• Unity's Netcode for GameObjects: A seamless networking solution built directly into Unity, ideal for small to medium sized games.
• Photon Unity Networking (PUN): A powerful third-party solution widely used for real-time multiplayer games.
• Mirror: An open-source high-level networking library built for Unity.

For this guide, we'll be using Unity's netcode for GameObjects as it provides a straightforward approach and integrates well with Unity's existing systems.

Step 1: Project setup

Start by creating a new Unity project. Open the Unity Hub, click the New Project button, choose a template that suits your game (2D or 3D) and give your project a name.

Installing Netcode for GameObjects

After creating your project, you'll need to install Unity's Netcode for GameObjects package:

1. Open your Unity project.
2. Go to Windows > Package Manager.
3. In the Package Manager, click the + Add icon and select Add package by name...
4. Enter com.unity.netcode.gameobjects in the dialog box and click Add.

Step 2: Basic networking setup

After installing the netcode packages, you will begin setting up the basic networking infrastructure. Start by creating a script to handle the networking logic.

Create a network manager

NetworkManager is needed to manage the state and logic of your multiplayer game. Create a new script named NetworkManager:

// NetworkManager.cs
using Unity.Netcode;
using UnityEngine;
public class NetworkManagerScript : MonoBehaviour {
    private void Start() {
        Debug.Log("Network Manager Initiated.");
    }
    public void StartHost() {
        NetworkManager.Singleton.StartHost();
    }
    public void StartClient() {
        NetworkManager.Singleton.StartClient();
    }
    public void StartServer() {
        NetworkManager.Singleton.StartServer();
    }
}

This script provides methods to start the game in host, server or client mode. Attach this script to a GameObject in your scene, for example, a GameController.

Configuring network prefabs

In a multiplayer game, players and objects must be synchronized across all clients and hosts. Set up a player prefab that will be instantiated for each player that joins the game:

1. Create your player object in the scene, for example, a simple cube or a character model.
2. Create Prefab by dragging your player object into Assets folder.
3. Add NetworkObject component to the player prefab.
4. In the Unity editor, click on the gameobject you attached NetworkManagerScript to.
5. In the Networking section of the Inspector, assign your player prefab to Network Prefabs list.

Step 3: Implementing the player's movement

For interaction between players in a multiplayer environment, we need to implement movement and sync that movement across the network. Create a script to handle player movement and attach it to your player prefab:

// PlayerMovement.cs
using UnityEngine;
using Unity.Netcode;
public class PlayerMovement : NetworkBehaviour {
    public float moveSpeed = 5f;
    private void Update() {
        if (IsOwner) {
            float moveX = Input.GetAxis("Horizontal");
            float moveZ = Input.GetAxis("Vertical");
            Vector3 move = transform.right * moveX + transform.forward * moveZ;
            transform.position += move * moveSpeed * Time.deltaTime;
        }
    }
}

In this script, if the player owns the object then it is allowed to move it, ensuring that only the correct player can control their character.

Step 4: Sync and networking

Once players can move, it is important that movement and actions are synchronized between all peers in the network. Unity's netcode provides capabilities through NetworkTransforms and RPC (Remote Procedure Call).

Network conversion

NetworkTransform component allows to automatically synchronize positional changes. Add this component to your player prefab:

RPC for player interaction

Remote Procedure Calls (RPC) are methods that are called on a remote client or server. These are used for events that need to be executed immediately, such as player actions or interactions.

// Example of an RPC call
[ServerRpc]
void PerformActionServerRpc() {
    // Example action possibly updating an item state
    Debug.Log("Server performing action.");
}

Server RPCs are initiated by the client and executed on the server, making them ideal for validating actions or propagating changes to all players.

Step 5: Testing the functionality

After the basic networking setup is complete, test the multiplayer functionality. Unity provides a Network Manager UI to help you easily test your multiplayer game.

Construction and testing

Create and run multiple instances of your game to simulate host and client players:

1. Go to File > Build Settings...
2. Make sure your current scene is added to the build.
3. Click on Build to create the game executable.
4. Run one instance as a host and the other as a client to test multiplayer connectivity and interaction.

Advanced topics

Once the basic multiplayer setup is working correctly, consider advanced topics like matchmaking, dedicated servers, and network optimization.

Matchmaking

Matchmaking involves pairing players in multiplayer games. Consider using Unity's matchmaking service or third-party services like Photon Cloud for this aspect.

Dedicated servers

Using a dedicated server offers many benefits, such as better stability and lower latency. You can deploy your server logic separately from the clients for scalability.

Conclusion

Setting up multiplayer in Unity requires understanding the basics of networking, synchronization, and efficient management of player interactions. By following this guide, you have learned how to set up a basic multiplayer project with player movement and testing components. Fine-tune your setup based on your specific game needs and continue to explore Unity's extensive networking capabilities for a rich multiplayer experience.

  Share This Article

If you find anything wrong with the article content, you can request an update