Inconsistencies in Instantiation Code

Questions & Answers
1

I’m using the code from Unity’s Instantiate tutorial (very slightly modified) to create projectiles in my project. However, I’m noticing that it works inconsistently. Most of the time when I click “Fire1” it creates one projectile properly. But other times it will either not create any projectile or create two of them that will launch at once. Here’s my code:

using UnityEngine;
using System.Collections;

public class UsingInstantiate : MonoBehaviour
{
	public Rigidbody rocketPrefab;
	public Transform barrelEnd;
	public int shotSpeed;
	
	
	void FixedUpdate()
	{
		if(Input.GetButtonDown("Fire1"))
		{
			Rigidbody rocketInstance;
			rocketInstance = Instantiate(rocketPrefab, barrelEnd.position, barrelEnd.rotation) as Rigidbody;
			rocketInstance.AddForce(barrelEnd.forward * shotSpeed);
		}
	}
}

Here’s the original tutorial for reference:
http://unity3d.com/learn/tutorials/modules/beginner/scripting/instantiate?playlist=17117

Any ideas what the problem is in my version, or if something else might be the cause?

2

Change FixedUpdate to Update, and it should fix when they don’t fire. I would imagine them double firing is something that’s not in this code.

Edit: Fixed is called on certain intervals, update is not. In most scenarios Update runs more often. Anything that is physics related should generally go in fixed update, things that aren’t sensitive to being called whenever possible (example being input), then use Update.