Problems with iTween and Instantiating objects

Questions & Answers
1

Hi there!

I’m pretty new to Unity (few months) and I’ve been mostly just hacking my project together to try to get it to an MVP status.

When I started my project, i just started spawning everything in the editor and referencing them in script through builtin arrays. Now, I went to clean up some stuff and I started running into all sorts of issues. This started because I changed how I was instantiating/referencing objects from script to now I instantiate the objects on startup vs. in the editor.

Basically, if my objects have iTween.Init(this.gameObject) inside of the Start() functions, I get a ton of the following problems when calling Instantiate on them:

  • My console starts telling me that a lot of objects have NullReferenceExceptions in the RetrieveArgs().
  • After that, it just spews a series of LateUpdate() and TwenUpdate() errors since the id of the object was null in the RetrieveArgs() iTween call… not sure why since the object is valid…

So, I remedied that a little by shoving the iTween.Init call inside of an Initialize function in every object that I want to use. However, during run time, when I go to Destroy/Instantiate another object, I get problems…

My questions are as follows:

  • Should I just go back and keep things using builtin arrays and not do any instantiating/creation during run time? Although before was more efficient, I’m just trying to know what it’s considered as “clean” by Unity standards…
  • Should objects that use iTween be mutually exclusive to objects that are created by using the Instantiate() method?
  • Could someone perhaps provide me an answer about what’s going on behind the scenes with iTween and the Instantiate() method?

Cheers!

3

I know this comes a few years late but I had the same issues and the NullReferenceExceptions only went away when I called

iTween.Init(this.gameObject);

from within Awake() inside a script that is bound to a PreFab.

For anyone stumbling upon this issue, it might come in handy…

2

I had the same issues as you.

I was following the docs/tutorials that mention that you should link a Prefab to a script by giving it a type of “Transform” in the script. When I changed it to a GameObject, I was able to use iTween with Instantiated prefabs.

I had the same TetrieveArgs() exception, but that was due to my accidentally Instantiating an object twice. I Instantiated, then executed the iTween command,and later in my script I was Instantiating and assigning to the same object. I fixed this by removing the 2nd one.