How to create a new GameObject, without adding it to the scene?

Question

I'm creating what is essentially my own prefab system. Game objects are defined by a human readable data file. I'd like to create an empty GameObject, load it with the components defined in the data file and have it ready and waiting for an Instantiate() call. However, whenever I use GameObject go = new GameObject() a new game object is added to the scene.

Using Unity built in prefabs, I can load a prefab as a GameObject, and it's not added to the scene. (See example below)

The rationale behind this is I'd like to have one list that contains GameObjects, some generated by loading Unity prefabs and others created by my custom prefab system. This needs to happen at run time, and can't involve the Unity Editor (since ideally end users would be able to define their own data files).

How can I create a new GameObject, without Unity automatically instantiating it for me?

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For example, I can make a call like this:

Resources.LoadAll("PrefabsDirectory", typeof(GameObject))

And I'll get a list of GameObjects, none of which are added to the scene when the call is made. Essentially, I'm creating a LoadAll method for my own prefabs, and likewise, I don't want to instantiate the GameObjects when the call is made.

Answer 1

You could change the GameObject's hideFlags?

I just tried running this:

GameObject myGameObject = new GameObject ();
myGameObject.name = "Obvious Name";

myGameObject.hideFlags = HideFlags.HideInHierarchy;

...and it's there, but it's not in the hierarchy. Technically, it's in the scene, but you don't see it until you change it's flags back to HideFlags.None. It's not the answer you're looking for, but at least as far as releasing this to developers goes, it's cleaner than grouping your objects.

Answer 2

You can't do that exact thing, unfortunately. However, you can accomplish the same design pattern (ie. abstract away the building of your objects, and then simply call them with a single command later) through a Factory pattern.

When you want an object, call something like Factory.CreateGameEntity(), and that method will handle everything behind the scenes.

Answer 3

There is no way to do go = new GameObject(); without adding it to the scene.

I'm working on an RTS where the player base needs to be persistent, and essentially, we serialize everything they've done and load it back in at run time using modified assets from the store.

Most output to XML or JSON so it's pretty straight forward to load the file and manipulate it as you wish.

Answer 4

The right way is to make a prefab , you allocate that prefab as an Object , then whenever you want to instantiate just use the reference of this Object and cast it as a GameObject.

ex :

private Object prefab;


public static GameObject Create(void)
{
   return (Instantiate(prefab , position , rotation) as GameObject);
}

Answer 5

To load a prefab into a variable so you can instantiate it later you would use the following code:

 GameObject ball = (GameObject)(Resources.Load ("myPrefab"));

I've done this in a project with Unity 5.5. It will be available to instantiate but not in the scene or part of the hierarchy until instantiated as normal.