API Multiplayer Chatroom • University Project — Programming APIs

Overview

For my Programming APIs university module, our team of three created a small multiplayer chatroom using Unity’s Netcode for GameObjects. I implemented the entire player-to-player communication system, from the text chat box and input handling to team-based visibility and player identification.

Footage

Image Gallery

My contributions

• Implemented team-restricted chat using ServerRpc and ClientRpc messaging in TeamChat.
• Created the singleton ChatUIManager that manages input fields and dynamically shows the correct team chat window.
• Built name-entry and team assignment systems (NameTag, PlayerID) with NetworkVariable<FixedString32Bytes> for synced data.
• Maintained the player list UI (PlayerListText) to reflect join/leave events across clients.
• Added FaceCamera utility to keep nameplates oriented to the active camera.

Representative code

// TeamChat.cs — send chat messages only to players on the same team
[ServerRpc(RequireOwnership = false)]
private void SendMessageServerRpc(string message, string team, ServerRpcParams rpcParams = default)
{
    BroadcastMessageToTeamClientRpc($"{playerID.PlayerName}: {message}", team);
}

[ClientRpc]
private void BroadcastMessageToTeamClientRpc(string message, string team)
{
    if (playerID.PlayerTeam.ToString() == team)
    {
        if (team == "Red")
            ChatUIManager.Instance.teamAChatDisplay.text += message + "\n";
        else if (team == "Blue")
            ChatUIManager.Instance.teamBChatDisplay.text += message + "\n";
    }
}

// PlayerID.cs — assign random team and propagate player name to all clients
private void AssignRandomTeam()
{
    string team = Random.Range(0, 2) == 0 ? "Red" : "Blue";
    playerTeam.Value = new FixedString32Bytes(team);
}

[ServerRpc]
private void AssignRandomTeamServerRpc()
{
    AssignRandomTeam();
}

Reflection

This project solidified my understanding of RPC flow, client-server authority, and NetworkVariable data replication within Unity. I also learned the importance of decoupling UI logic from networking so multiple clients can see consistent state updates.

Note: Built for my Programming APIs module to demonstrate teamwork, Netcode integration, and networked UI systems.