How can I make multiple objects to move between waypoints with 3 seconds delay ?

Unity Engine
,
1

What I’m trying to do is that each 3 second another object from a List will start moving between the waypoints.

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

public class Waypoints : MonoBehaviour
{
    public List<Transform> objsToMove = new List<Transform>();
    public LineRenderer lineRenderer;
    public float speed;
    public bool go = false;
    public bool moveToFirstPositionOnStart = false;
    public float rotSpeed;
    public bool random = false;
    public int currentCurvedLinePointIndex;

    private Vector3[] pos;
    private int index = 0;
    private bool goForward = true;
    private List<GameObject> curvedLinePoints = new List<GameObject>();
    private int numofposbetweenpoints;
    private bool getPositions = false;

    // Start is called before the first frame update
    void Start()
    {
        for(int i = 0; i < objsToMove.Count; i++)
        {
            var parent = GameObject.Find("Moving Object Parent");
            objsToMove[i] = Instantiate(objsToMove[i], parent.transform);
            objsToMove[i].name = "Platfrom";
        }

        curvedLinePoints = GameObject.FindGameObjectsWithTag("Curved Line Point").ToList();

        if (curvedLinePoints != null && curvedLinePoints.Count > 0)
        {
            //objToMove.transform.rotation = curvedLinePoints[1].transform.rotation;
        }
    }

    Vector3[] GetLinePointsInWorldSpace()
    {
        var positions = new Vector3[lineRenderer.positionCount];
        //Get the positions which are shown in the inspector 
        lineRenderer.GetPositions(positions);


        //the points returned are in world space
        return positions;
    }

    // Update is called once per frame
    void Update()
    {
        if (lineRenderer.positionCount > 0 && getPositions == false && CurvedLineRenderer.linesSet)
        {
            pos = GetLinePointsInWorldSpace();

            numofposbetweenpoints = curvedLinePoints.Count;

            if (moveToFirstPositionOnStart == true)
            {
                //objToMove.transform.position = pos[index];
            }

            getPositions = true;
        }

        if (go == true && lineRenderer.positionCount > 0 && CurvedLineRenderer.linesSet)
        {
            pos = GetLinePointsInWorldSpace();

            StartCoroutine(SendObjToMove());
           
            Move(objToMove);
        }
    }

    int cc = 0;
    private IEnumerator SendObjToMove()
    {
        yield return new WaitForSeconds(3f);


    }

    int counter = 0;
    int c = 1;
    void Move(Transform objToMove)
    {
        Vector3 newPos = objToMove.position;
        float distanceToTravel = speed * Time.deltaTime;

        bool stillTraveling = true;
        while (stillTraveling)
        {
            Vector3 oldPos = newPos;

            newPos = Vector3.MoveTowards(oldPos, pos[index], distanceToTravel);

            distanceToTravel -= Vector3.Distance(newPos, oldPos);
            if (newPos == pos[index]) // Vector3 comparison is approximate so this is ok
            {
                // when you hit a waypoint:
                if (goForward)
                {
                    bool atLastOne = index >= pos.Length - 1;
                    if (!atLastOne)
                    {
                        index++;
                        counter++;
                        if (counter == numofposbetweenpoints)
                        {
                            c++;

                            counter = 0;
                        }
                        if (c == curvedLinePoints.Count - 1)
                        {
                            c = 0;
                        }
                    }
                    else { index--; goForward = false; }
                }
                else
                { // going backwards:
                    bool atFirstOne = index <= 0;
                    if (!atFirstOne)
                    {
                        index--;

                        counter++;
                        if (counter == numofposbetweenpoints)
                        {
                            c++;

                            counter = 0;
                        }
                        if (c == curvedLinePoints.Count - 1)
                        {
                            c = 0;
                        }
                    }
                    else { index++; goForward = true; }
                }
            }
            else
            {
                stillTraveling = false;
            }
        }

        objToMove.transform.position = newPos;
    }
}

The part is :

if (go == true && lineRenderer.positionCount > 0 && CurvedLineRenderer.linesSet)
        {
            pos = GetLinePointsInWorldSpace();

            StartCoroutine(SendObjToMove());
           
            Move(objToMove);
        }

Then :

int cc = 0;
    private IEnumerator SendObjToMove()
    {
        yield return new WaitForSeconds(3f);


    }

The function Move should be called in the Update to make the objects to move.

Then I thought to use a coroutine for the 3 seconds delay. and using the variable cc for index of the objects to send each 3 seconds.

Before all that with the coroutine I just did :

foreach (Transform objToMove in objsToMove)
            {
                Move(objToMove);
            }

but that just send all the objects at the same time between the waypoints and I want to make a delay of X seconds between each object in the List objsToMove.

2

Delays are typically done with coroutines. A general purpose “do this function later” mechanism can be found here:

To debug the above, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run?
  • what are the values of the variables involved? Are they initialized?

Knowing this information will help you reason about the behavior you are seeing.

If you are running a mobile device you can also see the console output. Google for how.