Coroutines

/* How to use this script:

1. Drag the script to the trigger/s object/s (a button, a lever, etc) An elevator will have at least two triggers (one in the bottom floor and one in the top floor)

2. In the trigger object/s inspector:

a) Drag the elevator object to the Transform field

b. Type in the max top position and bottom position that the elevator will move */

using UnityEngine;

using System.Collections;

public class Elevator : MonoBehaviour {

    public Transform elevator;

    public float topPosition, bottomPosition;

    private bool isUp;

    void OnTriggerStay(Collider other)

    {

        if (other.gameObject.CompareTag("Player") && (!isUp) && Input.GetKey(KeyCode.E))

        {

            StartCoroutine("LiftingUp");

        }

        else if (other.gameObject.CompareTag("Player") && (isUp) && Input.GetKey(KeyCode.E))

        {

            StartCoroutine("LiftingDown");

        }

    }

    IEnumerator LiftingUp()

    {

        while (elevator.position.y < topPosition)

        {

            elevator.Translate(Vector3.up * .3f * Time.deltaTime);

            yield return null;

        }

        isUp = true;

    }

    IEnumerator LiftingDown()

    {

        while (elevator.position.y > bottomPosition)

        {

            elevator.Translate(Vector3.down * .3f * Time.deltaTime);

            yield return null;

        }

        isUp = false;

    }

}