Check to see if GameObject exists

I need to check to see if a referenced GameObject exists in the scene, but cannot do it by searching by name as it cannot have a unique name, so I am unsure of how to do this as all examples I have found are checking the object name which I cannot do.

I am referencing a GameObject like so:

Code (CSharp):

1. public GameObject activeObject;

and need a way to check if that SPECIFIC object, seeing as it was dragged in from the Heirarchy, is still in the scene or not.

 

Doesn't this just check to see if there is an object in the reference slot?
This is for an editor, and I need to tell the script that there is nothing there anymore if I use Destroy to delete the object.

 

What I am looking for more is a way to check if the referenced object is in the scene or not.

 

I don't know if this is exactly what you are looking for, but it is along the same lines:

http://docs.unity3d.com/ScriptReference/GameObject-activeInHierarchy.html

It should let you know if the object is active, but if you have things that are in the hierarchy and "turned off", then it probably wouldn't work for that.

There is also ID # generated by Unity that may or may not help you:

http://docs.unity3d.com/ScriptReference/Object.GetInstanceID.html

The ID is unique to each created object, so that would help you be specific, as you said.

 

Is it something like this you need?
If not then I am sorry.

Code (CSharp):

1. public GameObject activeObject;
2.  
3. void Start()
4. {
5.     activeObject = GameObject.Find("ObjectYouAreCheckingFor");
6. }
7.  
8. void Update()
9. {
10.     if(activeObject == null)
11.     {
12.         //Do something?
13.     }
14. }

 

That would be "if (activeObject != to null)" right?

 

It's not working any way. Not mine, not yours. It's weird.

 

Hey,

Wow this post is old. I did not expect that

Yes, if you want to check if it is currently in the scene, it would be != as opposed to ==.

Could you paste your code here? I assume it is the same as my previous post but just to make sure.

 

what if it's not refrenced?

 

Can't do anything without a reference. Get one. Presumably your method of getting one will fail if it's not there.

 

Thank you guys for this thread. I didn't declare a variable in mine. I just had it look for the object and used != null and it worked.

if (GameObject.FindGameObjectWithTag("CupOne")==null && maxValue >= .7f && maxValue < 1.7f && yAtSet - yOfThrow > -2 && yAtSet - yOfThrow < 2)
{

BallSpeed = 2.84f;


}

 

Had lot of troubles with this too, at first it worked only with tags, but then I figured out where was the problem

// Checks if object Dog(Clone) exists on the scene. We can't use just "Dog", because when prefab creates a copy it's always named as PrefabName + (Clone).

if (GameObject.Find("Dog(Clone)") == null)

 

This won't solve the problem. The variable activeObject could reference a gameobject that is not in the scene. So even if it wasn't null it could e.g. reference a prefab that doesn't exist in the scene.

I haven't tested this but activeObject.activeInHierarchy should work, I think.

 

This is probably bad to keep this thread alive, but I use a delayed function and it will fire off after my object is deleted sometimes. The way I check for deletion is this at the top of my function...

Code (CSharp):

1.  
2.         if (this == null) {
3.             return;
4.  
5.         }

I do this so that my function will just die if the object is gone. If you are also doing a delayed function, I recommend this.
Its simple, easy to read, and will solve the problem.
This ONLY checks if the instance of that script is still existent.

No extra reference needed if ran from the script on the gameobject that disappears. Hope it helps.