Networking Library for Unity + Steamworks
Moonrise Connect is a minimalistic Unity package and library that simplifies the development of peer-to-peer multiplayer games. The library currently only supports the Steam peer-to-peer network, building upon the Steamworks.Net wrapper for Valve's Steamworks API, but can be extended for other networking stacks. It was designed with simplicity in mind, to enable even the smallest teams to create realtime multiplayer experiences without spending most of their resources on networking.
Moonrise Connect is built around the concept of remote procedure calls. Any function in the code can be declared a Network Function. When a Network Function is called it is invoked simultaneously on all connected game instances. With this, the code can be written almost as if it was a singleplayer game. Whenever the host game instance encounters a Network Function, the library transmits the call to all the client game instances. When a client game instance reaches a Network Function it resumes without invoking the function, delaying the call until the corresponding message coming from the host game instance has arrived.
With this approach the same Network Functions with the same arguments are invoked on all game instances in the same order at approximately the same time. Resulting in a synchronized experience on all connected game instances.
For a more complete introduction check out the quickstart guide.
Moonrise Connect was originally developed for the frantic coop multiplayer game Clouds Ahoy!.
To use Moonrise Connect, first install Steamworks.Net by following the official installation instructions for Unity.
Next install Moonrise Connect from its git URL via the package manager.
public class Game : MonoBehaviour {
private Session Session { get; set; }
public void Initialize(CSteamID remoteSteamId) {
// Assuming there exists one chicken in the scene, register it as a Network Object
// Network Objects have to be registered on all game instances in exactly the same order
FindObjectOfType<Chicken>().RegisterGameObject();
// Initialize Moonrise Connect by creating a new session instance from the builder
Session = new Session.Builder().ForSteam().Build();
// Register a callback to be notified about changes in the network connection
Session.OnNetworkConnectionChanged += OnNetworkConnectionChanged;
// Define the connection by creating a configuration instance from the builder
// The configuration determines whether the instance acts as the host or a client game instance
var connectionConfig = new SteamNetworkConnectionConfig.Builder().AsHost(remoteSteamId).Build();
// Establish a connection with the other game instances
Session.EstablishConnection(connectionConfig);
}
public void OnNetworkConnectionChanged(object sender, NetworkConnectionEventArgs args) {
// Check the event type to learn what happened on the network connection
if (args.Type == NetworkConnectionEventArgs.Types.ConnectionEstablished) {
var chicken = FindObjectOfType<Chicken>();
// Wrap the function arguments and send them on the network to the target Network Function
// This will invoke the Network Function on all connected game instances
Invocation.Call(chicken.LayEgg, new Vector2(5, 8), 12f);
}
}
public void LateUpdate() {
// Poll the connection, collecting all incoming messages
Session.PollConnection();
// Invoke all Network Function calls that were received on the network or queued locally
Session.ProcessQueuedNetworkFunctionCalls();
}
}// Objects that participate in networking must be marked as Network Objects
[NetworkObject]
public class Chicken : MonoBehaviour {
// Functions that should be invoked on remote game instances must be marked as Network Functions
// The arguments specify which instances can call the the function and on which instances it is invoked
[NetworkFunction(Groups.Host, Recipients.All)]
public void LayEgg(Vector2 location, float size) {
Debug.Log("Hooray, I've laid an egg on all game instances");
}
}The Moonrise Connect package contains samples which can be imported through the Unity package manager after installing the Moonrise Connect package via Git.
The Block Buster sample provides a minimal setup demonstrating how Moonrise Connect can be used with Steamworks.Net.
To try it out make sure to have a valid steam_appid.txt file at the root of your Unity project as described by the Steamworks.Net installation guide. Also, all Steam accounts used for testing must have the game with the corresponding app id in their library.
If you use Moonrise Connect in your game please mention it in the credits and reach out to have the game added to this readme.
The package can be installed locally for development purposes.
To enable unity tests add the package to the testables array in the local package manifest of the local project.