Script to spawn AR object at specific time and then disappear it on click

Unity Engine
1

//I have been trying this script, using this the box spawn and disappears on click but the time condition is not fulfilled, it does not spawn after 1 minutes.

using System.Diagnostics;
using System.Threading;
using UnityEngine.XR.ARSubsystems;

public class Anime : MonoBehaviour
{
    List<ARRaycastHit> hits;
    System.DateTime oldDate;                        //the time that the game started
    System.DateTime currentDate;                    //the time since the start of the game
    int minutes;                            //the time passed in minutes
    public GameObject arobject;               //character: box
    public ARRaycastManager raycastManager;
  
    void Start()
    {
      
       minutes = 0;                                        //the number of minutes we have been on is 0
       oldDate = System.DateTime.Now;                        //the oldDate is the time at the start of the game
        arobject.SetActive(true);                       //box show at start
      

    }
    void Update()
    {
        if (Input.touchCount > 0)  // we touched the screen
        {
            Touch touch0 = Input.GetTouch(0);  //first touch in frame
            List<ARRaycastHit> allHits = new List<ARRaycastHit>();

            if (touch0.phase == TouchPhase.Began)
            {
                if (raycastManager.Raycast(touch0.position, allHits, TrackableType.Planes))  // if raycast is detecting a plane
                {
                    arobject.transform.position = allHits[0].pose.position;
                    arobject.SetActive(false);   //box disappears
                }
            }
        }
        currentDate = System.DateTime.Now;                //the current time is now
        minutes = currentDate.Minute - oldDate.Minute;    //the number of minutes passed is equal to the time right now minus the time the game was started
     
        if(minutes > 1){
            arobject.SetActive(true);
        }
    }

  
}
2

I would suggest using a Coroutine like so:

private void Start()
{
    StartCoroutine(SpawnAfterSeconds(60));
}

private IEnumerator SpawnAfterSeconds(float seconds)
{
    yield return new WaitForSeconds(seconds);
    // spawn object
    arObject.SetActive(true);
}

If the 60 second delay is fixed, I would suggest creating the WaitForSeconds object once in Start and reusing it to avoid creating a new one every time.
There is also Invoke(string methodName, float delay); which calls a method by name after a given amount of seconds, but I don’t like using it since it relies on the method name, meaning it’s not rename-proof (unless you use nameof(MethodName) instead of a string literal) and uses Reflection.
By the way, I don’t know if that is why your current solution failed, but it would (also) not work if the current time you store in oldDate is one minute before a full hour, because then you would never get minutes to be > 1, since DateTime.Minute is always in the [0…59] range.

EDIT: sorry, rereading the script I’m not sure I correctly understood what you’re after. If you want the object to (re-)spawn one minute after deactivating it by clicking on it, you would move the StartCoroutine call into the if-clause in line 32.

3

Hey, thanks for replying, I tried this, but this method is not working for building AR application, can you please suggest some other method!! I have tried inbuilt stopwatch from System.diagnostics, I have tried implementing a stopwatch that’s not working as well, is there something else I can do!
I am sharing the code, please ignore the comments:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.XR.ARFoundation;
using UnityEngine.EventSystems;
using System.Diagnostics;
using System.Threading;
using UnityEngine.XR.ARSubsystems;
public class Anime : MonoBehaviour
{
    List<ARRaycastHit> hits;
    public GameObject arobject;               //character: box
    public ARRaycastManager raycastManager;
   // public bool stopSpawning = false;
    void Start()
    {
    
    //    minutes = 0;                                        //the number of minutes we have been on is 0
    //    oldDate = System.DateTime.Now;                        //the oldDate is the time at the start of the game
        arobject.SetActive(true);                       //box show at start
       // StartCoroutine(SpawnAfterSeconds(60));
       //Invoke("SpawnObject", 10.0f);
    
    }

    // public void SpawnObject() {
    //     Instantiate(arobject, transform.position, transform.rotation);
    //     if(stopSpawning) {
    //         CancelInvoke("SpawnObject");
    //     }
    // }
    void Update()
    {
        if (Input.touchCount > 0)  // we touched the screen
        {
            Touch touch0 = Input.GetTouch(0);  //first touch in frame
            List<ARRaycastHit> allHits = new List<ARRaycastHit>();
            if (touch0.phase == TouchPhase.Began)
            {
                if (raycastManager.Raycast(touch0.position, allHits, TrackableType.Planes))  // if raycast is detecting a plane
                {
                    arobject.transform.position = allHits[0].pose.position;
                    arobject.SetActive(false);   //box disappears
                    StartCoroutine(SpawnAfterSeconds(60.0f));
                   
                    //arobject.SetActive(true);

                    // private void Start()
                    // {
                    //     StartCoroutine(SpawnAfterSeconds(60));
                    // }
                   
                   
                }
            }
        }
        // currentDate = System.DateTime.Now;                //the current time is now
        // minutes = currentDate.Minute - oldDate.Minute;    //the number of minutes passed is equal to the time right now minus the time the game was started
    
        // if(minutes > 1){
        //     arobject.SetActive(true);
        // }
    }
    IEnumerator SpawnAfterSeconds(float seconds)
                    {
                        yield return new WaitForSeconds(seconds);
                        // spawn object
                        arobject.SetActive(true);
                    }
}
4

Don’t use stopwatch.

You can use coroutines but they’re a little bit inappropriate if they could get stopped.

Personally I find it better just to use a private float myTimer;

Each frame that the condition to count time is true:

myTimer += Time.deltaTime;

When it is false:

myTimer = 0;

Each frame check if it has reached enough time;

if (myTimer > 1.0f)
{
  // enable or do the thing that you want to happen after 1 second
}