Hey everyone, In this post, we’re diving into a topic that’s crucial for any game developer: scene management. Specifically, we’ll be exploring how to level up your scene transitions by implementing a threaded loading approach, complete with a loading screen. In game development, efficient scene management is crucial for creating seamless transitions between different parts of the game. Additionally, providing visual feedback during scene loading can greatly enhance the player experience.
First things first, let’s introduce the SceneManager class. This class is going to be our go-to for managing scene transitions. But before we get into the nitty-gritty, let’s talk about the importance of scene management in game development.
Smooth scene transitions are like the glue that holds your game together. Whether your players are moving between levels, accessing menus, or triggering cutscenes, you want those transitions to be seamless. And that’s where the SceneManager comes in. Our SceneManager class is designed to be a singleton, ensuring that there’s only ever one instance floating around. This helps prevent any messy conflicts during transitions and keeps things running smoothly behind the scenes.
Now, let’s talk about the loading screen. We’ve all experienced those moments when a game seems to freeze up while loading a new scene. It’s not the most elegant experience, is it? That’s why we’ve implemented a loading screen feature right into our SceneManager class for simplicity sake, but of course it can be done in many different ways.
With our loading screen in place, players get a visual cue that something’s happening in the background. No more staring at a blank screen wondering if the game has crashed! Plus, with the option to use threads for asynchronous loading, we can keep the main thread free and the gameplay uninterrupted.
public partial class SceneManager : Node
{
public static SceneManager Instance { get; private set; }
private string _sceneToLoad = "";
private double _time = 0;
private double _minimumWaitTime = 2f;
private bool _useThread = false;
private string _loadingScreenScenePath = "res://loading_screen.tscn";
private LoadingScreen _loadingScreen;
private Array _progressArray;
public override void _Ready()
{
if (Instance == null)
{
Instance = this;
_loadingScreen = ResourceLoader.Load<PackedScene>(_loadingScreenScenePath).Instantiate<LoadingScreen>();
}
else
{
QueueFree();
}
}
/// <summary>
/// Go to scene without loading screen and without using threads
/// </summary>
/// <param name="scenePath"></param>
public void GoToSceneNoLoadingScreen(string scenePath)
{
var packedScene = ResourceLoader.Load<PackedScene>(scenePath);
var scene = packedScene.Instantiate();
var root = GetTree().Root;
// get current scene and remove it
var currentScene = root.GetChild(root.GetChildCount() - 1);
currentScene.QueueFree();
root.AddChild(scene);
}
/// <summary>
/// Go to scene with loading screen and using threads
/// </summary>
/// <param name="scenePath"></param>
/// <param name="minimumWaitTime"></param>
/// <param name="useSubThreads"></param>
public void GoToSceneThreadedWithLoadingScreen(string scenePath, double minimumWaitTime = 2f, bool useSubThreads = false)
{
AddChild(_loadingScreen);
_progressArray = new Array();
_useThread = true;
_minimumWaitTime = minimumWaitTime;
_sceneToLoad = scenePath;
// currently retun value is discarded
// but if you need to log more information, you can use the return value
_ = ResourceLoader.LoadThreadedRequest(path: scenePath, useSubThreads: useSubThreads);
}
public override void _Process(double delta)
{
if (_useThread)
{
_time += delta;
if (ResourceLoader.LoadThreadedGetStatus(_sceneToLoad, _progressArray) == ResourceLoader.ThreadLoadStatus.InProgress)
{
_loadingScreen.SetProgress(_progressArray.First().AsSingle() * 100);
}
else if (ResourceLoader.LoadThreadedGetStatus(_sceneToLoad,_progressArray) == ResourceLoader.ThreadLoadStatus.Loaded && _time > _minimumWaitTime)
{
// You can also use CallDeferred method to run at idle time
//CallDeferred(MethodName.LoadScene);
LoadScene();
}
// or use dummy % for loading screen
if (_time < _minimumWaitTime)
{
_loadingScreen.SetProgress((float)(_time / _minimumWaitTime) * 100);
}
}
}
private void LoadScene()
{
if (ResourceLoader.LoadThreadedGet(_sceneToLoad) is PackedScene packedScene)
{
var scene = packedScene.Instantiate();
var root = GetTree().Root;
// remove current scene
var currentScene = root.GetChild(root.GetChildCount() - 1);
currentScene.QueueFree();
root.AddChild(scene);
}
RemoveChild(_loadingScreen);
ResetParam();
}
public override void _ExitTree()
{
// if you add node manually, make sure to free it
_loadingScreen?.QueueFree();
}
private void ResetParam()
{
_time = 0;
_useThread = false;
}
}But how does it all work? Let’s break it down:
- Scene Loading Methods: We’ve provided two handy methods for transitioning between scenes. Need to jump to a new scene without any fuss? Use
GoToSceneNoLoadingScreen. Want to add some pizzazz with a loading screen? Opt forGoToSceneThreadedWithLoadingScreen. - Threaded Loading: By leveraging threads, we can load resources in the background while the game continues to run smoothly. This is especially useful for loading large scenes or assets without causing any dreaded lag spikes.
- Loading Progress: Our SceneManager class continuously updates the loading progress on the loading screen. Players can see exactly how far along the loading process is, keeping them engaged and informed. It can be further optimized by checking status between certain interval.
- Cleanup: We’ve made sure to clean up after ourselves with the
_ExitTreemethod. No orphaned nodes hanging around causing memory leaks here!
In conclusion, scene management is a critical aspect of game development, and with the right tools, you can take your game to the next level. By implementing a threaded loading approach and incorporating a sleek loading screen, you can create seamless transitions that keep players immersed in your game world.
Also check out the full source code with demo on GitHub!”
Check out my other post :
- Godot Engine – Build Custom Grid System using C#
- How to implement Google Game Play Services in Godot using C#.