我如何上下移动物体？

Question

Should i use StartCoroutine ?

using UnityEngine;
using System.Collections;
using System.Reflection;

public class DetectPlayer : MonoBehaviour {

    GameObject target;
    int counter = 0;
    public static bool touched = false;

    public float moveSpeed = 3.0f;
    public float smooth = 1f;
    private float distanceTravelled;
    private Vector3 startPositon;
    public float distanceToTravel = 50;

    private void Start()
    {
        startPositon = new Vector3(target.transform.position.x, target.transform.position.y, target.transform.position.z);
    }

    private void Update()
    {
        if (RaiseWalls.raised == true && touched == true)
        {
            MoveElevator();
            //touched = false;
        }
    }

    void OnCollisionEnter(Collision collision)
    {
        if (collision.gameObject.name == "ThirdPersonController") // "Platform"
        {
            Debug.Log("Touching Platform");
        }        
    }

    void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.name == "ThirdPersonController") // "OnTop Detector"
        {
            counter = 0;
            Debug.Log("On Top of Platform");
            target = GameObject.Find("Elevator");
            GameObject findGo = GameObject.Find("ThirdPersonController");
            GameObject findGo1 = GameObject.Find("Elevator");
            findGo.transform.parent = findGo1.transform;

            GameObject go = GameObject.Find("CubeToRaise");
            go.GetComponent<RaiseWalls>();
            Debug.Log("The button clicked, raising the wall");
            touched = true;
        }
    }

    void OnTriggerExit(Collider other)
    {
        GameObject findGo = GameObject.Find("ThirdPersonController");
        findGo.transform.parent = null;
    }

    void MoveElevator()
    {
        if (distanceTravelled == distanceToTravel)
        {

        }
        else
        {
            target.transform.localPosition += target.transform.up * Time.deltaTime * moveSpeed;
            distanceTravelled += Vector3.Distance(target.transform.position, startPositon);
        }
    }
}

In this case the elevator in the MoveElvator function is moving up. Now i want to make that when it's getting to the height 50 to start moving back down and to stop when detecting/getting to the ground.

So i added

if (distanceTravelled == distanceToTravel)
            {

            }

But not sure how to make it move down and stop when getting to the ground.

Answer 1

You need to keep some kind of state whether the elevator is moving up, down or staying still. You could use enums for that:

enum State{
   Idle,
   MovingUp,
   MovingDown
}

Now you just implement moving down and flip the direction when you are at the top or at the bottom.

Answer 2

Here is my script that I use:

float distance = 50;
float oneWayDuration;

void Start () {
    StartCoroutine(Mover(oneWayDuration, distance));
}

IEnumerator Mover(float oneWayDuration, float yDifference)
{
    Vector3 startPos = transform.position;
    Vector3 desirePos = new Vector3(startPos.x, startPos.y + 50 , startPos.z);
    float timeElapsed = 0f;

    while (timeElapsed < oneWayDuration)
    {
        timeElapsed += Time.deltaTime;
        transform.position = Vector3.Lerp(startPos, desirePos, timeElapsed / oneWayDuration);
        yield return new WaitForEndOfFrame();
    }
    while (timeElapsed < oneWayDuration)
    {
        timeElapsed += Time.deltaTime;
        transform.position = Vector3.Lerp(desirePos, startPos, timeElapsed / oneWayDuration);
        yield return new WaitForEndOfFrame();
    }
    //Just in case
    transform.position = startPos;
}