Advanced Scene Manager

Enhance your scene loading experience

Overview

This is a Unity package to simplify scene operations: load, unload and transition. In a quick example:

// Unity Manager scene transition
yield return SceneManager.LoadSceneAsync("my-loading-scene", LoadSceneMode.Additive);
yield return SceneManager.LoadSceneAsync("my-target-scene", LoadSceneMode.Additive);
SceneManager.SetActiveScene(SceneManager.GetSceneByName("my-target-scene"));
SceneManager.UnloadSceneAsync("my-loading-scene");
SceneManager.UnloadSceneAsync("my-previous-scene");

// Advanced Scene Management scene transition
sceneLoader.TransitionToScene(new LoadSceneInfoName("my-target-scene"), new LoadSceneInfoName("my-loading-scene"));

You can also take advantage of these features:

• Unified API for addressable and non-addressable scenes.
• Awaitable scene operations.
• Modular implementation with interfaces.
• Load, unload or transition to multiple scenes.

Migrating to 3.x

Refer to the Migration Guide at the wiki for instructions.

Summary

• Installation
  • OpenUPM
  • Installing from Git
  • Installing from tarball
• Dependencies
• Description
• Usage
  • The Scene Manager
  • Load Scene Info
  • The Scene Loaders
  • Scene Transitions
  • Disposable and CancellationTokens
• Practical examples
  • Creating your scene loader
  • Loading scenes with load scene info
• Creating Loading Screens
  • The Loading Behavior
  • The Loading States
  • The Loading Feedback
  • Loading Screen Example
• Why so many interfaces?
• Tests
• Troubleshooting
  • Error when creating an AdvancedSceneManager
  • Cannot unload a scene with a different ILoadSceneInfo

Installation

Open UPM

This package is available on the OpenUPM registry. Add the package via the openupm-cli:

openupm add com.mygamedevtools.scene-loader

Installing from Git

Note

Requires Git installed and added to the PATH

1. Open Window/Package Manager.
2. Click +.
3. Select Install package from git URL....
4. Paste https://github.com/mygamedevtools/scene-loader.git#upm into url.
5. Click Add.

Installing from tarball

1. Choose the release you want to install and download the com.mygamedevtools.scene-loader-<release>.tgz asset.
2. Open Window/Package Manager.
3. Click +.
4. Select Install package from tarball....
5. Select the com.mygamedevtools.scene-loader-<release>.tgz file you downloaded.

Dependencies

The package has no dependencies but supports integration with some packages. If you wish to use it with Addressables, UniTask, or TextMeshPro, make sure you install the packages:

• com.unity.addressables >= 1.19.0
• com.unity.textmeshpro >= 2.2.0
• com.cysharp.unitask* >= 2.0.0

*Installed via UPM or OpenUPM. Check the package documentation for more details.

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Description

Loading scenes in Unity is very simple, mostly, but when you start to deal with other systems such as Unity Addressables, it can get messy. Also, there are some common scene load scenarios that you'd usually reimplement in every project, like scene transitions.

In this package, you'll have the possibility to standardize the scene loading process between the standard Unity Scene Manager and Addressables, while still being able to choose how to await (if you want) the operations, be it Coroutines, standard Async (through ValueTasks) or UniTask.

Aside from the ordinary Load and Unload actions, the Scene Loading tools introduce the Transition as a new standard to control transitions between scenes with an optional intermediate "loading scene" in between. Also, starting from version 2.2 you can Load, Unload, and Transition to multiple scenes in parallel!

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Usage

Loading scenes with this package implies that the scenes will always be loaded as Additive. That is simply because there is no advantage in loading scenes in the Single load scene mode when you expect to work with multiple scenes.

To standardize how the scenes are loaded, you'll be using ISceneLoader, ISceneManager, and ILoadSceneInfo objects.

flowchart BT
  sm([Scene Manager])
  sl([Scene Loader])
  lsi([Load Scene Info])

  lsi -->|Load| sl
  lsi -->|Unload| sl
  lsi -->|Transition| sl
  sl -->|Load| sm
  sl -->|Unload| sm

Loading

These structures are meant to be used together. If you do not plan to use scene transitions or to have custom awaitable types, you don't need to use the ISceneLoader.

The Scene Manager

The ISceneManager interface exposes a few methods and events to standardize the scene load operations:

public interface ISceneManager : IDisposable
{
  event Action<Scene, Scene> ActiveSceneChanged;
  event Action<Scene> SceneUnloaded;
  event Action<Scene> SceneLoaded;

  int LoadedSceneCount { get; }
  int TotalSceneCount { get; }

  void SetActiveScene(Scene scene);

  ValueTask<Scene[]> LoadScenesAsync(ILoadSceneInfo[] sceneInfos, int setIndexActive = -1, IProgress<float> progress = null, CancellationToken token = default);

  ValueTask<Scene> LoadSceneAsync(ILoadSceneInfo sceneInfo, bool setActive = false, IProgress<float> progress = null, CancellationToken token = default);

  ValueTask<Scene[]> UnloadSceneAsync(ILoadSceneInfo[] sceneInfos, CancellationToken token = default);

  ValueTask<Scene> UnloadSceneAsync(ILoadSceneInfo sceneInfo, CancellationToken token = default);

  Scene GetActiveScene();

  Scene GetLoadedSceneAt(int index);

  Scene GetLastLoadedScene();

  Scene GetLoadedSceneByName(string name);
}

You can find many similarities between Unity's SceneManager class, and that's both for maintaining an easy learning curve as well as because some of these operations will end up calling the Unity Scene Manager internally (like SetActiveScene for instance). The ILoadSceneInfo interface is also showing up there, but we will get to that in a moment.

The package includes the AdvancedSceneManager that is capable of handling both addressable and non-addressable scene operations. You can use its implementation as a reference to build your own Scene Manager if you need.

The AdvancedSceneManager is expected to be used as a wrapper for the Unity SceneManager. When creating an AdvancedSceneManager you can decide whether you want it to manage scenes that have been loaded already or not.

flowchart TB
    usm([Unity Scene Manager])

    usm --> asm([Advanced Scene Manager])
    asm --> s_a["Scene [0]"]
    asm --> s_b["Scene [1]"]
    asm --> s_n["Scene [n]"]

Loading

The ISceneManager interface defines that both LoadSceneAsync and UnloadSceneAsync methods return a ValueTask<Scene>. This means you can await those methods if they are implemented with the async keyword, or you can also subscribe to the SceneLoaded or SceneUnloaded events to receive the same Scene you would via the async methods.

Both these methods also receive an ILoadSceneInfo object. So, instead of having multiple methods for receiving the scene's build index or the scene's name, we simply have an object instead.

Alternatively, you can also use the LoadScenesAsync and UnloadScenesAsync methods, to perform the operations on multiple scenes in parallel. These will return a ValueTask<Scene[]>.

You can create an AdvancedSceneManager using three constructors:

// Creates an advanced scene manager including all currently loaded scenes. Useful for most cases.
// Should not be called on `Awake()`, since it runs before the scene is loaded.
new AdvancedSceneManager(addLoadedScenes: true);

// Creates an empty advanced scene manager. Useful if you are doing this before any scene loads or in a bootstrap scene.
new AdvancedSceneManager();

// Creates an advanced scene manager including an array of scenes. Useful when you want to include only a specific set of scenes to it.
new AdvancedSceneManager(initializationScenes: new Scene[]);

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Load Scene Info

As its name states, it holds a reference to a scene to be loaded (or unloaded) and validates whether they can reference a loaded scene.

The ILoadSceneInfo interface simply defines:

public interface ILoadSceneInfo
{
  LoadSceneInfoType Type { get; }

  object Reference { get; }

  bool CanBeReferenceToScene(Scene scene);
}

Since the Reference field can hold any type of reference, the scene manager will be responsible for deciding what to do with its value. The LoadSceneInfoType is a simple enum that helps converting the Reference value without casting the ILoadSceneInfo object. The load scene info simply holds these references, and that's why the implementations included with the package are all readonly structs.

You can choose to work with five load scene infos:

flowchart
  subgraph Addressable
    direction TB
    assetref(LoadSceneInfoAssetReference)
    address(LoadSceneInfoAddress)
  end

  subgraph Unload only
    scene(LoadSceneInfoScene)
  end
  
  subgraph Non-Addressable
    direction TB
    name(LoadSceneInfoName)
    index(LoadSceneInfoIndex)
  end

Loading

• The LoadSceneInfoName, referencing a scene's name.
• The LoadSceneInfoIndex, referencing a scene's build index.
• The LoadSceneInfoScene, referencing a loaded scene's struct (used for unloading scenes only).
• The LoadSceneInfoAssetReference, referencing a scene's Addressable Asset Reference.
• The LoadSceneInfoAddress, referencing a scene's Addressable Address.

You can also build your own ILoadSceneInfo implementation if have special needs, but that will probably require you to build a scene manager to interpret its Reference value as well.

When unloading a scene, the AdvancedSceneManager will look for any of its loaded scenes that (in order of priority):

1. Have the same loaded scene handle (in the case of LoadSceneInfoScene).
2. Have the same ILoadSceneInfo.

That means that the preferable way to unload scenes is through LoadSceneInfoScene, as it holds a direct reference to the target scene. Assuming you don't have multiple scenes loaded with the same reference, it's safe to assume that the scene you want to unload is the one with the same ILoadSceneInfo you provided. Except from ILoadSceneInfoScene, you cannot unload a scene with a different ILoadSceneInfo type.

Note

If you do have multiple scenes loaded by the same reference, unloading by its ILoadSceneInfo will unload the last loaded scene of that reference.

Important

When unloading addressable scenes, their resources will be released by calling Addressables.UnloadSceneAsync internally.

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The Scene Loaders

The scene loader is an interface that you will use to load scenes in your game, as it works like a wrapper layer to the scene manager, but adds the Scene Transition operations. There are two base interfaces for scene loaders: one with a reference to the ISceneManager that will be used, and an async interface to be able to await the load operations.

The ISceneLoader interface defines:

public interface ISceneLoader : IDisposable
{
  ISceneManager Manager { get; }

  void TransitionToScenes(ILoadSceneInfo[] targetScenes, int setIndexActive, ILoadSceneInfo intermediateSceneInfo = null);

  void TransitionToScene(ILoadSceneInfo targetSceneInfo, ILoadSceneInfo intermediateSceneInfo = null);

  void UnloadScenes(ILoadSceneInfo[] sceneInfos);

  void UnloadScene(ILoadSceneInfo sceneInfo);

  void LoadScenes(ILoadSceneInfo[] sceneInfos, int setIndexActive = -1);

  void LoadScene(ILoadSceneInfo sceneInfo, bool setActive = false);
}

And the ISceneLoaderAsync:

public interface ISceneLoaderAsync<TAsyncScene, TAsyncSceneArray> : ISceneLoader
{
  TAsyncSceneArray TransitionToScenesAsync(ILoadSceneInfo[] targetScenes, int setIndexActive, ILoadSceneInfo intermediateSceneReference = default, CancellationToken token = default);
  
  TAsyncScene TransitionToSceneAsync(ILoadSceneInfo targetSceneReference, ILoadSceneInfo intermediateSceneReference = default, CancellationToken token = default);

  TAsyncSceneArray LoadScenesAsync(ILoadSceneInfo[] sceneReferences, int setIndexActive = -1, IProgress<float> progress = null, CancellationToken token = default);

  TAsyncScene LoadSceneAsync(ILoadSceneInfo sceneReference, bool setActive = false, IProgress<float> progress = null, CancellationToken token = default);

  TAsyncSceneArray UnloadScenesAsync(ILoadSceneInfo[] sceneReferences, CancellationToken token = default);

  TAsyncScene UnloadSceneAsync(ILoadSceneInfo sceneReference, CancellationToken token = default);
}

Note that the ISceneLoaderAsync interface inherits from ISceneLoader. The TAsyncScene type should return a Scene instance, and can be anything you mean to await, for example, Task<Scene>, ValueTask<Scene> or UniTask<Scene>, while the TAsyncSceneArray should return a Scene[] instance, such as Task<Scene[]>, ValueTask<Scene[]> or UniTask<Scene[]>.

The package comes with one base implementations and two wrappers:

• The SceneLoaderAsync, that just like the ISceneManager implementations, will return ValueTask values.
• The SceneLoaderCoroutine, that uses the SceneLoaderAsync but returns a WaitTask that can be used in coroutines.
• The SceneLoaderUniTask, that uses the SceneLoaderAsync but returns UniTask values.

All of them have interfaces to simplify your code:

public interface ISceneLoaderCoroutine : ISceneLoaderAsync<WaitTask<Scene>, WaitTask<Scene[]>> { }

public interface ISceneLoaderAsync : ISceneLoaderAsync<ValueTask<Scene>, ValueTask<Scene[]>> { }

public interface ISceneLoaderUniTask : ISceneLoaderAsync<UniTask<Scene>, UniTask<Scene[]>> { }

The Manager property can be used to listen to the SceneLoaded, SceneUnloaded, and ActiveSceneChanged events. Both LoadSceneAsync and UnloadSceneAsync methods will simply call the ISceneManager equivalents, while the LoadScene and UnloadScene will do the same but without await. It's important to understand that LoadScene, UnloadScene, and TransitionToScene will still invoke asynchronous operations, instead of blocking the execution until they are done. You can use the ISceneManager events to react to the completion of those methods.

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Scene Transitions

The Transition is a combination of load and unload operations to effectively perform scene transitions, with or without an intermediate scene. For example, usually, if you'd want to go from scene A to scene B you would:

1. Load the scene B.
2. Unload the scene A.

That's only two operations, right? What if you wanted to have a loading screen as well? In this case, you would:

1. Load the loading scene.
2. Load the scene B.
3. Unload the scene A.
4. Unload the loading scene.

That's four operations now. The TransitionToScene and TransitionToSceneAsync methods let you only provide where you want to go from the current active scene and if you want an intermediary scene (loading scene for example).

Also, aside from transitioning from the current active scene, you can also use the TransitionToSceneFromScenes and TransitionToSceneFromAll alternatives:

• TransitionToSceneFromScenes - unloads a given group of scenes during transition.
• TransitionToSceneFromAll - unloads all loaded scenes during transition.

Just like the regular Transition methods, its variants also have single/multiple scene options as well as async options.

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Disposable and CancellationTokens

Both the ISceneManager and the ISceneLoader interfaces implement IDisposable, meaning that the Scene Managers and Loaders should implement the Dispose() method. This is used with the CancellationToken parameters in ISceneManager methods to ensure that it will clear its internal data and stop async code execution during disposal. Note that even when its methods get canceled by the CancellationToken, the Unity Scene Manager methods are not cancellable and therefore will continue to operate when called.

The disposal of the implemented Scene Managers will clear its data and stop any running logic. This is useful for shutting down the application, for example. If you are going to manually dispose of your scene loaders or managers, prefer the following scenarios:

• You can ensure that there are no load/unload/transition operations in progress.
• You are quitting/shutting down the application or an application module.

Warning

It's not recommended to manually cancel the ISceneManager operations via its CancellationToken parameters. It may result in unexpected issues such as unwanted scenes being loaded/unloaded after cancellation.

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Practical Examples

When creating your scene loader, you must first create your scene manager. Ideally, you will not need to store the scene manager anywhere as it will be accessible through the ISceneLoader interface. Also, you will need to build your scene info objects to hold references to scenes.

Creating your scene loader

For the first example, let's build a scene manager and a Coroutine scene loader:

// Make sure to add 'using MyGameDevTools.SceneLoading;' on the top of the script
ISceneManager sceneManager = new AdvancedSceneManager();
ISceneLoader sceneLoader = new SceneLoaderCoroutine(sceneManager);

You can also define the scene loader types as their ISceneLoaderAsync implementations:

ISceneManager sceneManager = new SceneManager();

ISceneLoaderCoroutine coroutineSceneLoader = new SceneLoaderCoroutine(sceneManager);
// Or
ISceneLoaderAsync asyncSceneLoader = new SceneLoaderAsync(sceneManager);
// Or
ISceneLoaderUniTask unitaskSceneLoader = new SceneLoaderUniTask(sceneManager);

Note

It is recommended that you store these object references as its interfaces to reduce coupling in your code.

Loading scenes with load scene info

You'll use the load scene info objects to reference scenes. You can use these objects to define both addressable and non-addressable scenes.

Let's assume you have included the following scenes in your Build Settings:

0. Main Menu
1. Loading

And you have the following scenes in addressable groups:

• Shop
• Level 1

You can load the scenes by using the appropriate ILoadSceneInfo:

ILoadSceneInfo mainMenuSceneInfo = new LoadSceneInfoName("Main Menu");
ILoadSceneInfo loadingSceneInfo = new LoadSceneInfoIndex(1);
ILoadSceneInfo shopSceneInfo = new LoadSceneInfoAddress("Shop");
// You should be able to get the scene's Asset Reference from the inspector by exposing an
// AssetReference on a MonoBehaviour or ScriptableObject.
ILoadSceneInfo levelSceneInfo = new LoadSceneInfoAssetReference(levelSceneAssetReference);

// Loading the scene calls the same method, regardless of the load scene info type
sceneLoader.LoadScene(mainMenuSceneInfo);
sceneLoader.LoadScene(loadingSceneInfo);
sceneLoader.LoadScene(shopSceneInfo);
sceneLoader.LoadScene(levelSceneInfo);

// Or the async alternatives
await sceneLoader.LoadSceneAsync(mainMenuSceneInfo);
await sceneLoader.LoadSceneAsync(loadingSceneInfo);
await sceneLoader.LoadSceneAsync(shopSceneInfo);
await sceneLoader.LoadSceneAsync(levelSceneInfo);

The same logic applies for unloading scenes. Additionally, you can use the LoadSceneInfoScene to unload non-addressable scenes using the scene returned from ISceneLoaderAsync.LoadSceneAsync.

ILoadSceneInfo mainMenuSceneInfo = new LoadSceneInfoName("Main Menu");
ILoadSceneInfo loadingSceneInfo = new LoadSceneInfoIndex(1);
ILoadSceneInfo shopSceneInfo = new LoadSceneInfoAddress("Shop");

Scene levelScene = await sceneLoader.LoadSceneAsync(LoadSceneInfoAssetReference(levelSceneAssetReference));
ILoadSceneInfo levelSceneInfo = new LoadSceneInfoScene(levelScene);

sceneLoader.UnloadScene(mainMenuSceneInfo);
sceneLoader.UnloadScene(loadingSceneInfo);
sceneLoader.UnloadScene(shopSceneInfo);
sceneLoader.LoadScene(levelSceneInfo);

// Or the async alternatives
await sceneLoader.UnloadSceneAsync(mainMenuSceneInfo);
await sceneLoader.UnloadSceneAsync(loadingSceneInfo);
await sceneLoader.UnloadSceneAsync(shopSceneInfo);
await sceneLoader.LoadSceneAsync(levelSceneInfo);

Instead of using the async method, you can also register to the ISceneManager.SceneLoaded event:

sceneLoader.Manager.SceneLoaded += loadedScene => 
{
  ILoadSceneInfo loadedSceneInfo = new LoadSceneInfoScene(loadedScene);
  sceneLoader.UnloadScene(loadedSceneInfo);
}

For transitions, you can combine different load scene info objects on the transition method:

ILoadSceneInfo stageSceneInfo = new LoadSceneInfoName("Stage 1");
ILoadSceneInfo loadingSceneInfo = new LoadSceneInfoIndex(1);

sceneLoader.TransitionToScene(stageSceneInfo, loadingSceneInfo);

// Or the async alternative
await sceneLoader.TransitionToSceneAsync(stageSceneInfo, loadingSceneInfo);

Whenever you need to perform scene operations on multiple scenes, you can also build ILoadSceneInfo arrays:

ILoadSceneInfo[] sceneInfoGroup = new ILoadSceneInfo[]
{
  new LoadSceneInfoName("Main Menu"),
  new LoadSceneInfoIndex(1),
  new LoadSceneInfoAddress("Shop"),
  new LoadSceneInfoAssetReference(levelSceneAssetReference)
}

// Load
sceneLoader.LoadScenes(sceneInfoGroup);
// Unload
sceneLoader.UnloadScenes(sceneInfoGroup);
// Transition
// For multiple scenes, you must provide which scene you want to be the active scene by
// providing its index in the array.
sceneLoader.TransitionToScenes(sceneInfoGroup, 0);

// Awaitable alternatives
await sceneLoader.LoadScenesAsync(sceneInfoGroup);
await sceneLoader.UnloadScenesAsync(sceneInfoGroup);
await sceneLoader.TransitionToScenesAsync(sceneInfoGroup, 0);

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Creating Loading Screens

During scene transitions, you have the option to provide an intermediate scene that can be used as loading screen. This could be an animated splash screen or a loading progress bar, for example. This package provides implementations to help you build your loading screens faster.

The Loading Behavior

The Loading Behavior is a MonoBehaviour component, which you can attach to Unity GameObjects, that receives the progress value from the scene manager. You need to add a LoadingBehavior component to a GameObject in your loading scene to be able to display scene loading feedback. It exposes its LoadingProgress instance, which you can use to listen to the loading events:

public class LoadingProgress : IProgress<float>
{
  public event LoadingStateChangeDelegate StateChanged;
  public event SceneLoadProgressDelegate Progressed;

  public LoadingState State { get; }
}

The StateChanged event expects a LoadingState parameter, to report the current state of the scene loading operation, and you can query the active state at any time by retrieving the value in the State property. The Progressed event expects a float parameter, ranging from 0 to 1 to report the progress of the scene loading operation.

Back to the LoadingBehavior, it has a few options you can set on the Unity Inspector:

• Wait For Scripted Start: enable if the loading screen will have a transition in effect, such as a fade in.
• Wait For Scripted End: enable if the loading screen will have a transition out effect, such as a fade out.

The Loading States

The loading scene transition can be customized to delay some parts of the operation to deliver a smooth visual experience for the user. That means we can fade in/out or use other transition effects and wait for them to complete to continue the scene loading operations. The LoadingState enum reflects those states:

public enum LoadingState
{
  WaitingToStart,
  Loading,
  TargetSceneLoaded,
  TransitionComplete
}

These states are ordered, which means that the first state will always be WaitingToStart and the last will be TransitionComplete. They mean:

• WaitingToStart: it's waiting for a trigger to allow the scene loading to start loading. This could be if the loading scene does not instantly appear, otherwise causing weird experiences with things simply disappearing. You can transition the loading screen with a fade in or a similar effect, for example.
• Loading: the loading screen transition has occurred and the scene loading operation is running. During this state, the LoadingProgress instance will receive the progress value from the scene manager.
• TargetSceneLoaded: the target scene has been loaded, but the loading screen is still displaying. You can use this state to transition the loading screen out, such as a fade out or a similar effect.
• TransitionComplete: the target scene has been loaded and the loading screen is already out of the way. Shortly after this state, the loading scene will be unloaded.

The Loading Feedback

At this point, you should already have your loading scene with a LoadingBehavior attached to one of your GameObjects. Now you can also add some other components to display the loading progress feedback. This package comes with three feedbacks:

• LoadingFeedbackSlider: attach on an UI Slider to display the loading progress feedback as a progress bar.
• LoadingFeedbackTextMeshPro: attach on an UI Text Mesh Pro to display the loading progress feedback as text normalized from 0 to 100.
• LoadingFeedbackText (also known as Legacy): attach on an UI Legacy Text to display the loading progress feedback as text normalized from 0 to 100.

You can use a combination of these feedback components in the loading scene. Remember to assign the LoadingBehavior field of these components to the LoadingBehavior component you created before.

Another feedback that you could make is a fade in/out effect. The LoadingFader component does just that. Add it to an [UI CanvasGroup] GameObject to control the group's alpha value during the visual transitions. You can also set the fade time and customize the fade in/out animation curves to suit your preference.

To use the LoadingFader effectively, you must enable both WaitForScriptedStart and WaitForScriptedEnd toggles in your LoadingBehavior component.

Loading Screen Example

Take the following loading screen scene hierarchy as an example:

• Canvas - (Canvas, CanvasScaler, LoadingBehavior)
  • Group - (CanvasGroup, LoadingFader)
    • Background - (Image)
    • Text_Message - (TextMeshProUGUI)
    • Slider_Progress - (Slider, LoadingFeedbackSlider)
      • Text_Progress - (TextMeshProUGUI, LoadingFeedbackTextMeshPro)

By having this hierarchy in your loading scene, it would be able to fade in/out and display both the loading progress bar and loading progress text feedback. As this scene has the LoadingFader component, remember to enable both WaitForScriptedStart and WaitForScriptedEnd toggles in the LoadingBehavior component. Also, if you're not using an addressable scene manager, enable the ReducedLoadRatio toggle.

You can test this scene by passing its ILoadSceneInfo reference as the intermediateSceneInfo in an ISceneLoader.TransitionToScene method.

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Why so many interfaces?

The idea behind the interfaces is first to decouple things and second to allow you to build your custom implementations if you require something very different from the included content. Sometimes projects require very specific implementations, and instead of making the system extremely complex and detailed, I'd rather have it broken into many different pieces that you can replace to fit with whatever works best for you.

Tests

This package includes tests to assert most use cases of the Scene Managers and Scene Loaders. The tests do not have any effect on a runtime build of the game, they only mean to work in a development environment.

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Troubleshooting

Error when creating an AdvancedSceneManager

When creating an AdvancedSceneManager passing a true value to its constructor, as new AdvancedSceneManager(true), it attempts to add all loaded scenes to its list of tracked scenes. However, if you called that during Awake(), you might see the error:

ArgumentException: Attempted to get an {nameof(ISceneData)} through an invalid or unloaded scene.

This error is thrown because during Awake() the scene is not fully loaded and cannot be added to the list of tracked scenes.

Move your call to Start() instead.

Cannot unload a scene with a different ILoadSceneInfo

In a case where you have loaded a scene via one type of ILoadSceneInfo, you can only unload it by using the same type or explicitly a LoadSceneInfoScene. For example:

ILoadSceneInfo nameInfo = new LoadSceneInfoName("MyScene");
ILoadSceneInfo indexInfo = new LoadSceneInfoIndex(3);

sceneManager.LoadSceneAsync(nameInfo);

// You **cannot** do this:
sceneManager.UnloadSceneAsync(indexInfo);

// But you can do this:
sceneManager.UnoadSceneAsync(nameInfo);

// Or, build a `LoadSceneInfoScene`.
// Alternatives: GetLoadedSceneByName(name), GetLoadedSceneAt(index), GetLastLoadedScene() or GetActiveScene()
ILoadSceneInfo sceneInfo = sceneManager.GetLoadedSceneByName("MyScene");
sceneManager.UnloadSceneAsync(sceneInfo);

Sometimes this issue can also be avoided by performing a scene transition. If you're trying to unload the active scene to transition between scenes, you can execute the transition through the scene manager and let it handle the internal complexity. For example:

// Instead of unloading the source scene directly:
sceneManager.LoadSceneAsync(targetSceneInfo)
sceneManager.UnloadSceneAsync(sourceSceneInfo);

// Perform a scene transition:
sceneManager.TransitionToScene(targetSceneInfo);

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---

Don't hesitate to create issues for suggestions and bugs. Have fun!