How can I active trigger looking this one?

Questions & Answers
1

I need to understand how can I do to active some trigger when I look this trigger.
I have created this script:

    using UnityEngine;
    using System.Collections;

    public class Rotating_Normal_Door : MonoBehaviour {

public bool open = false;
public bool interaction = false;
public bool locked = false;

private Animator anim;
private int openDoor = Animator.StringToHash("Open");

void Start () {
	anim = GetComponent<Animator> ();
}

void Update () {
	if (Input.GetKeyDown ("e") && interaction == true && locked == false) {
		changeDoorState ();
	}
}

void OnTriggerEnter (Collider col) {
	if (col.gameObject.tag == "Player")
	{
		interaction = !interaction;
	}
}

void OnTriggerExit (Collider col) {
	if (col.gameObject.tag == "Player")
	{
		interaction = !interaction;	
	}
}

void changeDoorState ()  {
	if (open == false) {
		anim.SetBool (openDoor, true);
		open = true;
	}
	else {
		anim.SetBool (openDoor, false);
		open = false;
	}
}	
    }

When I enter into the trigger I will be able to press E to open the door, but I want add the condition that I will be able to press E only when I look the trigger.
How can i do that? Please help!

2

I guess you can send a Raycast. Send it directly from the middle of the screen to door and if it hits the door, you know the character/player is looking directly at it.