Installation & Project Setup

This networking library is designed to be used inside Unity, and it expects you to set up two separate Unity projects: one for the Client and one for the Server. The server project runs the authoritative simulation, while the client project runs the player-facing game.

Prerequisites

Unity (2021 or newer recommended)
.NET 4.x scripting runtime
The Lidgren.Network library (already bundled in this project)
Basic familiarity with Unity scenes, prefabs, and components

Project Layout

You should create two Unity projects side by side:

MyGame/
  ├── Client/      (Unity project for the client build)
  └── Server/      (Unity project for the server build)

This separation makes it easier to build, deploy, and test each role independently. Both projects can share code via Unity packages or a shared folder linked into each project.

Adding the Library

Copy the following scripts into both projects: - UCNetwork.cs - ClientNetwork.cs - ServerNetwork.cs - NetworkSync.cs
Make sure the Lidgren.Network.dll dependency is available in your project. You can place it inside Assets/Plugins/ in both Client and Server.
(Optional) If you want voice chat later, also include VoIPManager and related stubs, though these are not required.

Unity Scene Setup

Client Scene

Create a new empty GameObject called NetworkManager.
Add the ClientNetwork component to it.

(Optional) Add your own bootstrap script to handle connecting:

public class ClientBoot : MonoBehaviour
{
    public ClientNetwork client;

    void Start()
    {
        client.Connect("127.0.0.1", UCNetwork.port, "Player01", "", "Player", 0);
    }
}

Server Scene

Create a new empty GameObject called ServerManager.
Add the ServerNetwork component to it.

(Optional) Add your own script to handle approvals and logging:

public class ServerBoot : MonoBehaviour
{
    public ServerNetwork server;

    void ConnectionRequest(ServerNetwork.ConnectionRequestInfo info)
    {
        // Example: approve everyone for now
        server.ConnectionApproved(info.id);
    }
}

Networking Prefabs

All prefabs that you want to instantiate across the network must:

Be placed in a Resources/ folder.
Contain a NetworkSync component.
Have a unique name (the prefab name is sent across the network).

Example:

Assets/
  └── Resources/
      ├── PlayerAvatar.prefab
      ├── Monster.prefab
      └── Door.prefab

Ports and Firewall

Default port: 603 (set in UCNetwork.port).
Make sure this port is open on your server host machine.
Clients must know the server’s IP address (LAN or WAN).

Testing in Editor

You can run the server project in one Unity editor instance and the client project in another.
For local testing, connect to 127.0.0.1.
For multiple clients, run multiple builds of the client project while the server runs in Editor.

Headless Server Builds

For deployment, build the server project as a headless Unity build:

In the build settings, select Server Build or add the -batchmode -nographics command line arguments.
This runs without rendering and uses fewer resources.

Checklist

[ ] Create two Unity projects: Client and Server.
[ ] Add core scripts (UCNetwork, ClientNetwork, ServerNetwork, NetworkSync) to both.
[ ] Place networked prefabs with NetworkSync in a Resources/ folder.
[ ] Add a ClientNetwork component to your Client scene.
[ ] Add a ServerNetwork component to your Server scene.
[ ] Test locally by running both projects and connecting to 127.0.0.1.

Summary

Use two Unity projects: one for the server, one for the client.
Add ClientNetwork or ServerNetwork to a manager GameObject.
Networked prefabs must live in Resources/ and include NetworkSync.
Default port is 603; open it on your host.
Test locally first, then deploy the server as a headless build.