How to use a Google account to authenticate users in Unity?

Introduction

This article will guide you through the process of using a Google Account to authenticate users in your Unity projects. This method offers a seamless and secure way for players to access your game using their existing Google credentials.

Setting up Google Cloud Project

1. Create a Project

Go to the Google Cloud Console and create a new project.

2. Enable Google Sign-In

Within your project, enable the Google Sign-In API from the “APIs & Services” section.

Creating Credentials

1. Create OAuth 2.0 Client IDs

Navigate to “APIs & Services” > “Credentials” and click “Create credentials” > “OAuth client ID”.

• Select “Web application” as the application type.
• Provide a name for your application.
• Enter your authorized redirect URIs. For Unity, use “http://localhost:8080/auth” or “http://localhost:8080”.

2. Download Credentials

Download the JSON file containing your client ID and secret. This file will be crucial for integrating with your Unity project.

Unity Implementation

1. Install Google Play Games Plugin

Download the Google Play Games Plugin for Unity from GitHub and import it into your project.

2. Configure the Plugin

• Locate the “Google Play Games” settings in your Unity project.
• Paste the contents of your downloaded JSON file into the “Google Web Client ID” field.
• Select the correct “Signing in” button style.

3. Implement Google Sign-In

using GooglePlayGames;
using GooglePlayGames.BasicApi;

public class GoogleSignIn : MonoBehaviour
{
    public void SignIn()
    {
        PlayGamesPlatform.Instance.Authenticate(SignInInteractivity.CanPromptOnce, OnAuthenticationFinished);
    }

    private void OnAuthenticationFinished(bool success)
    {
        if (success)
        {
            Debug.Log("Successfully signed in with Google Account.");
            // Access user information using PlayGamesPlatform.Instance.localUser
        }
        else
        {
            Debug.Log("Failed to sign in with Google Account.");
        }
    }
}

4. Handle User Information

Once signed in, you can access user information like username and profile picture using the `PlayGamesPlatform.Instance.localUser` object.

string username = PlayGamesPlatform.Instance.localUser.userName;
string profilePictureURL = PlayGamesPlatform.Instance.localUser.playerImageUrl;

Sign Out

To sign the user out:

PlayGamesPlatform.Instance.SignOut();

Comparison with Traditional Methods

Conclusion

Integrating Google Sign-In into your Unity projects offers a convenient and secure way for users to access your game. By leveraging Google’s robust authentication system, you can streamline the user experience and provide a secure environment for your game.