How to make a missile locking system?

Questions & Answers
1

How does one create a locking system where if you look at a certain object, the lock-on timer increases, but as soon as you look away or look at a different object, the lock-on timer resets to zero. When the lock-on timer reaches a certain point, the target becomes locked, and any missile fired will curve towards that object. The lock will be maintained for a set amount of time, even if you look away or look at a different object. And if the lock-on is broken, a missile fired during the time when a lock on was established will still maintain what was previously locked. Pretty much a “fire-and-forget” kind of system.

Basically what I’m having trouble is how do you check that what you’re looking at in the current frame is the same as what you were looking at in the previous frame? It’s that “check to see if you’re still looking at something, or you’ve looked away” that I can’t seem to do.

I’m using Raycasts to do the “looking” part, but I don’t know how to perform that check if one uses Raycasts. Perhaps Raycasts aren’t the answer?

Answer in javascript please.

2

It’s actually very simple.

I’m not gonna get into how to make the missle move realisticly as that deals with Slerps, which aren’t hard, but tweaking them the way you want is lol.

Do something like this (in C#)
Add this to your PROJECTILE.

public GameObject target;
public float Speed = 40.0f; // Change to your liking.

void Update(){

transform.LookAt(target);
tranform.Translate(Vector3.forward * Speed * Time.deltaTime);
}
3

For

check to see if you’re still looking
at something, or you’ve looked away

You can maintain a variable that stores the instance ID of the object you are currently looking at. You can decide the object you’re looking at using Raycast.

Something like the script below. Note that this is not a working script, it is just to illustrate the logic:

var currentObjectInstanceID : int = null;

function Update()
{
	var fwd = transform.TransformDirection (Vector3.forward);
	if (Physics.Raycast (transform.position, transform.forward, hit)) {
		// You are looking at one of the target objects
		hit.collider.gameObject.tag == "LookAtTargets"{
			// You were previously not looking at any object and now you are looking at an object which is one of the target objects
			if(currentObjectInstanceID == null)
			{
				currentObjectInstanceID = hit.collider.gameObject.GetInstanceID();
			}
			// You were previously looking at the same object
			else if(currentObjectInstanceID == hit.collider.gameObject.GetInstanceID())
			{
				// You are currently looking at the same object. Keep adding to the lock timer of this object
			}
			// You were previously looking at different object but you are still looking at another target object
			else if(currentObjectInstanceID != hit.collider.gameObject.GetInstanceID())
			{
				// You are now looking at different target. Start lock timer for this object.
			}
		}	
		// Or you are not looking at any of the target object
		else
		{
			// You are not looking at any target objects
			currentObjectInstanceID = null;
			
			// Reset the timer to zero for your target object
		}
	}
}

And you can use the method suggested by @N1warhead for making it follow the target after it is fired.