5 Essential Tips for Optimizing Your Photon Unity Networking Game

It is quite a powerful tool for multiplayer games using Photon Unity Networking, but with power comes the responsibility to optimize your PUN-based game in order to give a seamless and responsive experience for your players. In this article, we are going to take five must-know tips that would help you optimize your PUN game to the next level of multiplayer experience.

1. Use RPCs Wisely

RPCs is a vital feature of PUN, enabling code execution on remote clients. However, overusing RPCs results in network overload. Here are some do’s and don’ts:

• Use RPCs only when there are occasional necessary events, but not for continuous updates;
• Merge several updates into one RPC whenever possible;
• For frequent updates, you can use the built-in PUN synchronization methods. Image showing RPC use efficiently vs inefficiently

2. Interest Management

Interest Management. The amount of game state each player receives is restricted to only what is of interest to him. This will consequently significantly reduce networking traffic and improve performance in general. Have a look at these strategies:

• Use PUN’s built-in Interest Groups to segment your game world
• Enforce distance-based relevancy on updates
• Utilize PUN’s auto management: cull update frequency based on distance to also provide an intuitive understanding of how interest management works for a game world

3. Serialization Optimization

Serialization can help significantly reduce the amount of data going over the network. Here’s a few tips:

• Use PUN’s built-in compression for Vector3 and Quaternion
• Implement custom serialization for complex objects
• Use fixed-point numbers instead of floating-point when precision allows.

public class OptimizedTransform : MonoBehaviourPun, IPunObservable
{
    private Vector3 networkPosition;
    private Quaternion networkRotation;

    public void OnPhotonSerializeView(PhotonStream stream, PhotonMessageInfo info)
    {
        if (stream.IsWriting)
        {
            // Compress and send position and rotation
            stream.SendNext(transform.position);
            stream.SendNext(transform.rotation);
        }
        else
        {
            // Receive and decompress position and rotation
            networkPosition = (Vector3)stream.ReceiveNext();
            networkRotation = (Quaternion)stream.ReceiveNext();
        }
    }

    void Update()
    {
        if (!photonView.IsMine)
        {
            // Smoothly interpolate to the network position and rotation
            transform.position = Vector3.Lerp(transform.position, networkPosition, Time.deltaTime * 10);
            transform.rotation = Quaternion.Slerp(transform.rotation, networkRotation, Time.deltaTime * 10);
        }
    }
}
      

4. Use Object Pooling

Object pooling can significantly improve performance, especially in games with many short-lived objects (like projectiles). Here’s how to implement it with PUN:

public class PhotonPoolManager : MonoBehaviourPunCallbacks
{
    public static PhotonPoolManager Instance;
    public GameObject[] prefabs;
    private Dictionary> pools = new Dictionary>();

    void Awake()
    {
        Instance = this;
        foreach (GameObject prefab in prefabs)
        {
            pools[prefab.name] = new Queue();
        }
    }

    public GameObject Spawn(string prefabName, Vector3 position, Quaternion rotation)
    {
        if (!pools.ContainsKey(prefabName))
        {
            Debug.LogError($"Pool for prefab {prefabName} doesn't exist.");
            return null;
        }

        GameObject obj;
        if (pools[prefabName].Count == 0)
        {
            obj = PhotonNetwork.Instantiate(prefabName, position, rotation);
        }
        else
        {
            obj = pools[prefabName].Dequeue();
            obj.transform.position = position;
            obj.transform.rotation = rotation;
            obj.SetActive(true);
        }

        return obj;
    }

    public void Despawn(GameObject obj)
    {
        obj.SetActive(false);
        pools[obj.name].Enqueue(obj);
    }
}
      

5. Implement Lag Compensation

Lag compensation is crucial for maintaining a fair and responsive game experience. Here are some techniques:

• Use client-side prediction for immediate responsiveness
• Implement server reconciliation to correct prediction errors
• Use interpolation for smooth movement of other players

Applying these optimizing techniques will significantly increase the performance and experience with a player’s PUN-based multiplayer game. Remember that optimizing is never something you do once forever but rather always keep going: monitor, suggest improvements, and refine as your game is developed.