Find GameObject in another loaded scene

Questions & Answers
1

How do I find or reference a GameObject loaded in another scene?

I’ve tried with GameObject.Find() and Scene.GetSceneByName("myScene").GetRootGameObjects(), but they both failed, one because it seemingly doesn’t recognize objects outside its current scene and the other because it only returns an empty array.

Edit: the scene was loaded additively

1 Like
2

When you switch scene all objects in that first scene will be deleted (unless they are set as DoNotDestroy).
Also you can load a scene in Additive mode, that will keep objects until you unload that scene.

3

Instead of using Scene.GetSceneByName, why not use one of the overloads for SceneManager.LoadScene, which returns a Scene. For example:

var parameters = new LoadSceneParameters(LoadSceneMode.Additive);
var scene = SceneManager.LoadScene("MyAdditiveScene", parameters);
        
foreach (var obj in scene.GetRootGameObjects())
{
     Debug.Log(obj.name);
}

I don’t know if this will change anything but it seems like it would work.

4

Maybe these will help. Though be cautious, these are heavy functions. Don’t use them in Update() etc. Cache their results.

Usage:

var yourComp = FindComponentUtils.FindComponentInAllLoadedScenes<YourComp>(includeInactive: true);

Source:

using System.Collections.Generic;
using System.Linq;

public static class FindComponentUtils
{
    /// <summary>
    /// Returns a Component of type T in all loaded scenes.
    /// Be aware that this may also return an object which is scheduled for destruction at the end of the current frame.
    /// Be double aware that this will NOT return any object marked as "DontDestroyOnLoad" since those are moved to a
    /// unique scene which is not accessible during runtime.
    /// See: https://gamedev.stackexchange.com/questions/140014/how-can-i-get-all-dontdestroyonload-gameobjects
    /// </summary>
    /// <param name="path"></param>
    /// <param name="scenePredicate">Use this to exclude scenes from being searched.</param>
    /// <returns></returns>
    public static T FindComponentInAllLoadedScenes<T>(bool includeInactive, System.Predicate<UnityEngine.SceneManagement.Scene> scenePredicate = null)
    {
        var components = FindComponentsInAllLoadedScenes<T>(includeInactive, scenePredicate);
        if (components.Count > 0)
        {
            return components[0];
        }

        return default(T);
    }

    /// <summary>
    /// Returns all Components of type T in all loaded scenes.
    /// Be aware that this may also return objects which are scheduled for destruction at the end of the current frame.
    /// Be double aware that this will NOT return any objects marked as "DontDestroyOnLoad" since those are moved to a
    /// unique scene which is not accessible during runtime.
    /// See: https://gamedev.stackexchange.com/questions/140014/how-can-i-get-all-dontdestroyonload-gameobjects
    /// </summary>
    /// <param name="path"></param>
    /// <param name="scenePredicate">Use this to exclude scenes from being searched.</param>
    /// <returns></returns>
    public static List<T> FindComponentsInAllLoadedScenes<T>(bool includeInactive, System.Predicate<UnityEngine.SceneManagement.Scene> scenePredicate = null)
    {
        // TODO: For Unity2020+ we could use Object.FindObjectsOfType with includeInactive = true instead.
        UnityEngine.SceneManagement.Scene[] scenes = new UnityEngine.SceneManagement.Scene[UnityEngine.SceneManagement.SceneManager.sceneCount];
        for (int i = 0; i < UnityEngine.SceneManagement.SceneManager.sceneCount; ++i)
        {
            var scene = UnityEngine.SceneManagement.SceneManager.GetSceneAt(i);
            if (scenePredicate == null || scenePredicate(scene))
            {
                scenes *= UnityEngine.SceneManagement.SceneManager.GetSceneAt(i);*

}
}

return FindComponentsInScenes(includeInactive, scenes);
}

public static List FindComponentsInScenes(bool includeInactive, params UnityEngine.SceneManagement.Scene[] scenes)
{
try
{
return scenes
.Where(s => s.IsValid())
.SelectMany(s => s.GetRootGameObjects())
.Where(g => includeInactive || g.activeInHierarchy)
.SelectMany(g => g.GetComponentsInChildren(includeInactive))
.ToList();
}
catch (System.Exception)
{
return new List();
}
}
}