SendMessage

I was trying to figure out how to call a function attached to another GameObject and recalled from other discussions the SendMessage call. Is that the only / proper way to do this? If there are others, where could I get more information about them?

Thanks!

-- Clint

 

If you have a reference of the GameObject, you can try to get the relevant script:

var yourScript : YourScript = someGO.GetComponent( YourScript );

If "yourScript" (variable) is null, then the GameObject "someGO" doesn't have this particular component.

If it is not null, you can proceed like this:

yourScript.CallRelavantFunction();

However, I have no idea if this is better than to call SendMessage on it.

 

Okay, I tried that and get this weird error that makes no sense to me.

Code (csharp):

1.  
2. gun.Fire();
3.  

I am making that call and Fire is a function on the gun GameObject. Up above I define the var gun this way:

Code (csharp):

1.  
2. var gun : GameObject;
3.  

And I assigned that GameObject to a game object.

The error is:

'Fire' is not a member of 'UnityEngine.GameObject'

Any ideas?

Thanks,

-- Clint

 

If your script is type "Gun" (i.e. the script name), then you can probably use:

Code (csharp):

1.  
2. var gun : Gun;
3.  

Since you are currently declaring you gun variable as a GameObject type, the compiler is complaining because when it looks at the GameObjectt class, it does not find a fire function.

 

I see what you are saying. I tried that and it doesn't seem to be working for me. The object gun is actually under the object robot. Robot is where I want to make the call to Fire which lives in a script on gun.

Does that make sense?

Thanks,

-- Clint

 

Not sure if this will help.

Access a varible from another script.

http://forum.unity3d.com/viewtopic.php?p=16344&highlight=#16344

 

If you declare the gun variable public, you can drag the robot object onto it in the inspector, and the variable will automatically get assigned the Gun component.

The code could look something like this:

Code (csharp):

1.  
2. // GunShooter.js
3. //   -- a script attached to some other game object
4.  
5. var theGun : Gun; // <-- drag the robot object onto
6.                   //     this variable
7.  
8. // This one requires the object also to have a collider
9. // or a GUIText or GUITexture
10. function OnMouseUp() {
11.     if(theGun) { // test that the gun is there
12.         theGun.Fire(); // fire the gun
13.     }
14.     else { // if theGun is not assigned
15.         Debug.Log("You need to assign a value to the Gun");
16.     }
17. }
18.  
19.  

You should also take a look at the pages about Accessing Other Components and Accessing Other Game Objects in the scripting overview.

 

I have read the reference material and some of that I have read multiple times. Overall it makes sense and I am slowly piecing together how the messaging works but are still struggling a bit. I used the last example provided (mine looked like this, stripped down a bit):

Code (csharp):

1.  
2. var theGun : gun;
3.  
4. function Update () {
5.      theGun.Fire();
6. }
7.  

gun is actually a GameObject which is a child to robot. robot has the script the above code is in.

I am getting this error now:

The name 'gun' does not denote a valid type

Thanks for all the help!

-- Clint

 

gun is the name of the GameObject and is lowercase.

Thanks,

-- Clint

 

Ah okay. Thanks!

So when I declare the script then in the inspector I need to drag the gameobject the script lives on. Or at least that is what I seemed to need to do. Is that correct?

A question about performance regarding SendMessage versus calling the function directly. Is there a difference for speed, overhead, etc.? Or are they interchangeable?

Thanks,

-- Clint

 

Excellent! Thanks for the help everyone!

Regards,

-- Clint