2D Instantiated object stops moving when used with timer

Question

Hello I'am trying to make a system that instantiate and object, and the moves it to a set of waypoints. When i use intantiate in the Start() function it travels like intended through the waypoints, but when i add the instantiate line to my update() function it only travels a little while and then stops, the same goes for the rest of the instantiated objects. It has something to do with timer i guess, but i have tried a few approaches, but they all lead to the same thing. Hope someone can help.

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

public class waypointTest : MonoBehaviour
{
[SerializeField] private Transform[] waypoints;

public GameObject waypointInvader;
GameObject go;        
private int nextUpdate = 1;
public float speed = 5f;
private int waypointIndex;




void Start()
{               
    
}
void Update()
{
    if (Time.time >= nextUpdate)
    {
        nextUpdate = Mathf.FloorToInt(Time.time) + 1;
        go = Instantiate(waypointInvader, transform.position, transform.rotation) as GameObject;            
    }        

    
    if (go.transform.position != waypoints[waypointIndex].transform.position)
    {
        Vector3 newPos = Vector3.MoveTowards(go.transform.position, waypoints[waypointIndex].transform.position, speed * Time.deltaTime);
        go.transform.position = newPos;
        if (newPos == waypoints[waypointIndex].transform.position)
        {
            waypointIndex += 1;
        }
        if (waypointIndex == waypoints.Length)
        {
            waypointIndex = 0;
        }
    }
    
}
}

score 1 · Answer 1 · answered Oct 15 '21 at 12:54

The problem is that you are loosing the reference to the object you want to move.

If instantiate is inside Start():

go is set to be the instantiated object
go is moved to every waypoint
go is moved to the very first waypoint
go is moving through the waypoints again

If instantiate is inside Update():

go is set to be the first instantiated object
go is moved to a few waypoints until Time.time >= nextUpdate returns true
go is set to be the second instantiated object and will loose its reference to the first go
The first go stops moving
The second go starts moving
Repeat

One way to solve this problem is to give the moving object go its own movement script. That way you just have to instantiate go and it will handle its movement by itself. If go does not know where the waypoints are you can give it to it after instantiating (For example waypointInvader is a prefab). E.g.:

if (Time.time >= nextUpdate)
{
    nextUpdate = Mathf.FloorToInt(Time.time) + 1;
    go = Instantiate(waypointInvader, transform.position, transform.rotation) as GameObject;
    go.GetComponent<GoMovement>().ListOfWaypoints = waypoints;
}

2D Instantiated object stops moving when used with timer

1 Answers1