Is Attachment by Transform.Position Good Practice?

Question

Hi. As with most of the askers here, I'm fairly new to all this.

Basically, I wanted to make a simple NPC trigger for initiating dialogue when the player is close enough. I originally made a trigger mesh (cylinder) as a child of the NPC, and put some onTriggerEnter/onTriggerExit code on it.

The code worked fine for entering, but hardly ever for exiting. After an evening of Googling, it seems there is some kind of bug with onTriggerExit (or, at least, a lot of people aren't doing it right, myself included), and I also found that when I disabled the Animator on my NPC, onTriggerExit worked fine.

So, my solution was to unchild the trigger cylinder and stick—

 transform.position = NPC.transform.position;

—in the trigger's update function, which fixed the problem; it now works perfectly.

So, my question is this: is this method likely to cause any problems I might be missing due to my noobiness? Is more resource intensive, for example, or is there potential for the trigger cylinder to lag behind a moving NPC?

Thank you for any help.

Answer 1

Best Answer

Answer by dannyskim · Sep 18, 2013 at 04:18 PM

Having an update like this is not terribly expensive. In this case, I think you're worrying about optimization a little too much.

Just make sure to cache both of the transforms and used the cached references instead of a direct lookup and it should be perfectly fine to do that.

0 Show 3 · Share

b3agz · Sep 18, 2013 at 05:50 PM 0

Share

Thanks. I just wanted to be sure. Just for clarification, when you say cache instead of direct lookup, do you mean putting the object into the script, ie:

 public transform NPC;

as opposed to something like;

 NPC = GameObject.Find("NPC");

or did you mean something else?

dannyskim · Sep 18, 2013 at 09:57 PM 0

Share

Something along those lines. NPC specifically would probably already be a cached object, what I was more pointing too was accessing transform every frame.

Instead, you should op to cache the transform if you're going to be doing a lot of lookups on it:

 private Transform _transform;
 
 void Start()
 {
     _transform = transform;
 }
 
 void Update()
 {
     _transform.position = NPC.transform.position;
 }

even a transform.position lookup does GetComponent behind the scenes, so caching it will be best for performance reasons.

b3agz · Sep 18, 2013 at 09:59 PM 0

Share

Ahh, thanks. I didn't know that.

Is Attachment by Transform.Position Good Practice?

1 Reply

Your answer

Welcome to Unity Answers

Follow this Question

Related Questions