Tutorial: Make a Real-Time Multiplayer Game with Unity 3D and Azure Cloud- Part 1

Introduction

Today, I will walk you through setting up a real-time multiplayer game using Unity 3D, Azure Cloud, and OAuth authentication.

This tutorial will guide you through the essential steps to build a multiplayer game with secure authentication and cloud hosting using C# and the Unity engine.

We’ll be using:

• Unity 3D for game development
• Photon PUN for real-time multiplayer networking
• Azure Functions & App Services for cloud backend
• Azure PlayFab for game services
• OAuth (Microsoft Identity or Google OAuth) for authentication

Step 1: Setting Up Your Unity Project

1.1 Install Unity and Create a New Project

Ensure you have Unity Hub and Unity 2022+ installed. Create a 3D project and name it something cool like AzureMultiplayerGame.

1.2 Import Photon PUN for Multiplayer

Photon PUN (Photon Unity Networking) is a great way to get started with multiplayer games.

1. Open Unity and go to Window > Package Manager.
2. Click Add package from git URL and paste:

   1	https://github.com/ExitGames/Photon-Unity-Networking.git

3. Install the package and create a Photon account at Photon Engine.
4. In Unity, go to Photon > PUN Wizard and enter your App ID.

Boom! Multiplayer setup ✅.

Step 2: Implementing Authentication with OAuth (Azure AD)

2.1 Set Up an Azure AD Application

1. Go to Azure Portal.
2. Navigate to Azure Active Directory > App Registrations > New Registration.
3. Enter an app name (UnityOAuthGame) and set Redirect URI to https://localhost/oauth2.
4. Copy the Client ID and Tenant ID.

2.2 Implement OAuth in Unity (C#)

Install the Microsoft Authentication Library (MSAL) via NuGet or Unity Package Manager.

Create an AuthManager.cs script:

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using System;
using System.Threading.Tasks;
using Microsoft.Identity.Client;
using UnityEngine;

public class AuthManager : MonoBehaviour
{
    private IPublicClientApplication _clientApp;
    private string[] _scopes = { "User.Read" };
    private string _clientId = "YOUR_CLIENT_ID";
    private string _tenantId = "YOUR_TENANT_ID";

    void Start()
    {
        _clientApp = PublicClientApplicationBuilder.Create(_clientId)
                    .WithAuthority(AzureCloudInstance.AzurePublic, _tenantId)
                    .WithRedirectUri("https://localhost/oauth2")
                    .Build();
    }

    public async Task SignIn()
    {
        try
        {
            var result = await _clientApp.AcquireTokenInteractive(_scopes).ExecuteAsync();
            Debug.Log("Signed in: " + result.Account.Username);
        }
        catch (Exception ex)
        {
            Debug.LogError("OAuth Error: " + ex.Message);
        }
    }
}

Attach this script to a GameObject in Unity and call SignIn() to authenticate players. 🔑

Step 3: Setting Up Azure PlayFab for Game Services

Azure PlayFab is a backend-as-a-service for games.

3.1 Register for PlayFab

1. Go to PlayFab and create an account.
2. Create a new Title and copy your Title ID.

3.2 Integrate PlayFab in Unity

1. Install the PlayFab SDK via Unity Package Manager.
2. Create a PlayFabManager.cs script:

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using PlayFab;
using PlayFab.ClientModels;
using UnityEngine;

public class PlayFabManager : MonoBehaviour
{
    public void LoginWithOAuth(string authToken)
    {
        var request = new LoginWithCustomIDRequest
        {
            CustomId = authToken,
            CreateAccount = true
        };

        PlayFabClientAPI.LoginWithCustomID(request, OnLoginSuccess, OnLoginFailure);
    }

    private void OnLoginSuccess(LoginResult result)
    {
        Debug.Log("PlayFab login success! Player ID: " + result.PlayFabId);
    }

    private void OnLoginFailure(PlayFabError error)
    {
        Debug.LogError("PlayFab login failed: " + error.GenerateErrorReport());
    }
}

Call LoginWithOAuth(authToken) after signing in with OAuth.

Step 4: Implementing Real-Time Multiplayer Logic

4.1 Create a Multiplayer Room

Modify MultiplayerManager.cs to create a room:

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using Photon.Pun;
using UnityEngine;

public class MultiplayerManager : MonoBehaviourPunCallbacks
{
    public void CreateRoom()
    {
        PhotonNetwork.CreateRoom("Room1", new Photon.Realtime.RoomOptions { MaxPlayers = 4 });
    }

    public override void OnJoinedRoom()
    {
        Debug.Log("Joined room: " + PhotonNetwork.CurrentRoom.Name);
    }
}

Call CreateRoom() when the player clicks Start Game.

4.2 Spawning Players

Modify GameManager.cs to instantiate a player:

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using Photon.Pun;
using UnityEngine;

public class GameManager : MonoBehaviour
{
    public GameObject playerPrefab;

    void Start()
    {
        PhotonNetwork.Instantiate(playerPrefab.name, new Vector3(0, 0, 0), Quaternion.identity);
    }
}

NOTE
Unity3d is very versatile and can target many platforms. All the techniques here apply to iPhone-iOS, Android , as well as Windows and Mac.

Unity3d has the ability to target web pages- by compiling to web assembly. BUT the caveot is when you are running on a web page, your code can talk back to the server it came from , but cannot make calls out to other domains (cross origin issues).