[Unity v5.3] Simple elevator

Elevator.cs

/**
 * A simple elevator script. Can be attached to any object to make it move in the given direction.
 * Requires a button that calls CallElevator().
 */

using UnityEngine;
using System.Collections;

public class Elevator : MonoBehaviour {
	/// <summary>
	/// The distance between two floors
	/// </summary>
	public Vector3 FloorDistance = Vector3.up;
	public float Speed = 1.0f;
	public int Floor = 0;
	public int MaxFloor = 1;
	public Transform moveTransform;

	private float tTotal;
	private bool isMoving;
	private float moveDirection;


	// Use this for initialization
	void Start () {
		moveTransform = moveTransform ?? transform;
	}

	// Update is called once per frame
	void Update () {
		if (isMoving) {
			// elevator is moving
			MoveElevator();
		}
	}

	void MoveElevator() {
		var v = moveDirection * FloorDistance.normalized * Speed;
		var t = Time.deltaTime;
		var tMax = FloorDistance.magnitude / Speed;
		t = Mathf.Min (t, tMax - tTotal);
		moveTransform.Translate(v * t);
		tTotal += t;
		print (tTotal);

		if (tTotal >= tMax) {
			// we arrived on floor
			isMoving = false;
			tTotal = 0;
			Floor += (int)moveDirection;
			print (string.Format("elevator arrived on floor {0}!", Floor));
		}
	}

	/// <summary>
	/// Start moving up one floor
	/// </summary>
	public void StartMoveUp() {
		if (isMoving)
			return;

		isMoving = true;
		moveDirection = 1;
	}

	/// <summary>
	/// Start moving down one floor
	/// </summary>
	public void StartMoveDown() {
		if (isMoving)
			return;

		isMoving = true;
		moveDirection = -1;
	}

	/// <summary>
	/// Tell the elevator to move up or down
	/// </summary>
	public void CallElevator() {
		if (isMoving)
			return;

		print ("elevator starts moving!");

		// start moving
		if (Floor < MaxFloor) {
			StartMoveUp ();
		}
		else {
			StartMoveDown ();
		}

	}
}

ElevatorButton.cs

/**
 * A simple ElevatorButton, can be used to cause an Elevator start moving up or down.
 */

using UnityEngine;
using System.Collections;

public class ElevatorButton : MonoBehaviour {
	public Elevator Elevator;

	void OnTriggerEnter(Collider collider) {
		var go = collider.gameObject;
		var player = go.GetComponent<Player> ();

		if (player != null && Elevator != null) {
			Elevator.CallElevator ();
		}
	}
}