Is it possible to broadcast to all objects in scene?

Question

Is there a way to send a broadcast to all gameobjects in a scene (without requesting all gameobjects with findObjectsOfType and send it to them individually)?

It would be good enough if there's a way to iterate through the root GameObjects in the scene, then I could just use Broadcast on these gameobjects.

Answer 1

Answer by Jaap Kreijkamp · Feb 26, 2010 at 09:53 AM

It seems there isn't, so as performance isn't a real issue for me as I only use to call it when starting and ending a level, this is my solution:

public static void BroadcastAll(string fun, System.Object msg) {
    GameObject[] gos = (GameObject[])GameObject.FindObjectsOfType(typeof(GameObject));
    foreach (GameObject go in gos) {
        if (go && go.transform.parent == null) {
            go.gameObject.BroadcastMessage(fun, msg, SendMessageOptions.DontRequireReceiver);
        }
    }
}

Don't know if I win anything with broadcasting to root objects instead of just use SendMessage on all gameobjects returned, but it works.

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Answer 2

Answer by Motionreactor · Feb 26, 2010 at 03:36 PM

Really simple solution is to make everything in your scene a child of a single GameObject (call it world if you like). Then from this 'world' GameObject you can broadcast to all children:

gameObject.BroadcastMessage("ReceiverFunction", msg)

and place a simple script in every child you wish to receive the message:

function ReceiverFunction(msg)
{
    //do something with msg
}

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Jaap Kreijkamp · Feb 27, 2010 at 03:26 AM 0

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Yeah a good one, but really, I don't want the performance hit of an extra matrix multiply of an extra level in hierarchy depth for a broadcast I do only twice in a level. I don't know how much impact the extra level would have but the transformation and scale would probably not be free, if it's zero and identity.

Motionreactor · Feb 27, 2010 at 05:06 AM 0

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I wouldn't imagine it'd be a large overhead. I would assume that the efficiency gained through simpler message broadcast would offset the loss in matrix addition (which would surely be $$anonymous$$iscule anyway?) Or am I wrong? (little experience to go on there)

Fattie · Mar 08, 2015 at 05:41 AM 0

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the overhead is nothing. but it's definitely true it's not an elegant, always-usable solution... (note -- apart from anything else, in 100% of projects you have persistent objects that come in an out of the scene for various reasons .. they would "miss out" in this scheme you know?)

Answer 3

Answer by andeeee · Feb 25, 2010 at 05:05 PM

There isn't a way to do this directly. The best thing I can think of is to add a tag to all root objects. You could then get them all with FindGameObjectsWithTag and broadcast to each of them.

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Jaap Kreijkamp · Feb 26, 2010 at 09:49 AM 2

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Except I use tags already for other purpose, but thanks.

Answer 4

Answer by $$anonymous$$ · Nov 27, 2015 at 09:30 AM

you should use events instead https://unity3d.com/learn/tutorials/modules/intermediate/scripting/events

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WarpZone · Mar 03, 2018 at 09:17 PM -1

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If you're making a complex system to sell on the appstore with lots of separate scripts talking to each other, DON'T USE EVENTS! Ins$$anonymous$$d of spaghetti, it turns your code into teleporting spaghetti!

Answer 5

Answer by insominx · Mar 22, 2012 at 08:42 AM

You could always climb the tree to get the root and broadcast from there. This has worked for me:

 Transform root = this.transform;
 while (root.parent != null) {
     root = root.parent;
 }

 root.BroadcastMessage("MyMessage");

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Chirokidz · Aug 23, 2013 at 02:52 AM 3

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there is a transform.root property for this purpose. Also, that's not the question, the question is sending the message to ALL root objects, not just the root of the current object.

JiMMaR Chirokidz · Feb 21, 2016 at 04:30 PM 0

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I didn't know about the root property ! thanks a bunch !

insominx · Aug 29, 2013 at 11:36 PM 0

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I didn't know about root. Has that always been there? As for the root of this object, all paths lead to the root level. It doesn't matter which one you start from.

Lohoris2 · Dec 19, 2014 at 09:26 AM 0

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You totally misunderstand how root works: http://docs.unity3d.com/ScriptReference/Transform-root.html

Is it possible to broadcast to all objects in scene?

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