Sequential GameObject Activation

Question

This seems like the simplest thing but I can't figure it out for the life of me.

I have 400 unique GameObjects that I would like to Activate at different times during an animation. Each GameObject needs to be at very exact location and rotation so I believe .SetActive would be better than trying to Instantiate each one individually. It would also be nice to avoid writing a 400 item Hashtable or Dictionary.

I am simply trying to create a script that will:

Disable Current GameObject
Find next GameObject
Enable next GameObject

Here is my current attempt at naming each GameObject a number 1-400 and converting a variable back-and-forth between a String and an Int:

 private var currentObject : int = 1;
 
 function NextFrame () {
 
     currentObject.ToString();
     
     GameObject.Find("currentObject").SetActive (false);
     
     int.Parse(currentObject) += 1;
     
     GameObject.Find("currentObject").SetActive (true);
 }

Answer 1

Best Answer

Answer by DavidDebnar · Jul 10, 2013 at 01:57 PM

Here's a modified version of your method. First, the gameobjects tagged 'Animate' are stored in a list and then sorted by name. Then each tick, it does basically the same as your script, but uses the array to look the gameobjects up instead of the .Find method.

 import System.Linq;
 
 private var gameObjectList : GameObject[];
 private var currentObject : int = -1;
  
 function Start () {
     gameObjectList = GameObject.FindGameObjectsWithTag("Animate").OrderBy(function(g){g.SetActive(false);return g.name;}).ToArray();
 }
  
 function NextFrame () {
     gameObjectList[(currentObject++%gameObjectList.Length+gameObjectList.Length)%gameObjectList.Length].SetActive(false);
     gameObjectList[currentObject].SetActive(true);
 }

--David--

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yotingo · Jul 10, 2013 at 11:17 PM 0

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Thanks for the response! Your answer is very helpful.

I am unfamiliar with System.Linq apparently it is a part of the .net framework, according to my research. Everything else I understand except: OrderBy(function(g) g.name).

I set up all my GameObjects with the Animate tag and everything seems to be function except the script doesn't proceed to activate the second game object after disabling the first. So the first time function 'NextFrame' is called GameObject "0" is disabled but GameObject "1" is never set active.

I appreciate your help.

DavidDebnar · Jul 10, 2013 at 11:43 PM 0

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I've editted the code a bit, but also make sure, that all your gameobjects are active.

DavidDebnar · Jul 10, 2013 at 11:47 PM 0

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And as for Linq, it's used to do stuff like sorting with arrays/lists/dictionaries/etc.

yotingo · Jul 11, 2013 at 09:27 AM 0

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All your help has been great, it works perfectly! I can't thank you enough for taking the time to help me out with this. I am going to include a special thanks to you in the credits of my project and a link to your answer.

Thanks!

Answer 2

Answer by TonyLi · Jul 10, 2013 at 01:49 PM

Try this:

 var objectHolder : GameObject;
 private var objects : Transform[];
 private var current : int;
 
 function Start() {
     objects = objectHolder.GetComponentsInChildren(Transform) as Transform[];
     for (var t : Transform in objects) {
         t.gameObject.SetActive(false);
     }
     current = 0;
     objects[current].gameObject.SetActive(true);
 }
 
 function NextFrame() {
     objects[current].gameObject.SetActive(false);
     current = (current + 1) % objects.Length;
     objects[current].gameObject.SetActive(true);
 }

Notes:

Put your 400 objects under a single game object in the hierarchy, and assign this object to the objectHolder property of the script.
The Start() function makes an array of all of the objects under the objectHolder, and activates only the first one.
The NextFrame() function just cycles through the array.
You should check bounds and check for null, but I omitted that for clarity.
Untested code, but it should get the idea across. [Edit: Still untested, but should probably work now. :-)]

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yotingo · Jul 10, 2013 at 10:51 PM 0

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Thanks for the fast response, I really appreciate it. I was unaware that an array could be filled automatically.

The script you suggested seems pretty straightforward but for some reason the screen turns grey at start and remains that way. All objects inside my 'objectHolder' are disabled properly on start but the first object (0 in the array) is never set active (same with the following objects). I'm not sure what is causing the script to freeze. When I disable the script in the inspector, the grey screen no longer appears and the rest of the game functions as intended.

I'm sure the answer is obvious, I apologize for my oversight.

TonyLi · Jul 11, 2013 at 03:05 AM 0

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Hence my note #5 (untested code) :-). I edited my answer. I wasn't thinking before. FindObjectsOfType grabbed all the objects in the whole scene, which turned off everything.

The edited version above uses GetComponentsInChildren() to get every Transform component in the objectHolder hierarchy (and just the objectHolder hierarchy, not the whole scene). Be aware that it also grabs objectHolder's transform, but I don't if that's a big deal for you or not.

yotingo · Jul 11, 2013 at 09:36 AM 0

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Thank you again for taking the time to help me. Your approach to the problem really helped me understand what I was doing wrong in my attempts.

I wish I had enough rep to up-vote your answer! I will give thanks in the credits of my project and I hope it will raise awareness of your mad coding skillz :)

Sequential GameObject Activation

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