Play Audio in sequence from children objects

It is hard to understand what you mean by playing once. Because you can collect 4 triggers at once, play all of them by sequence, after it save them for next playing. And play when you will collect some new triggers also. For example:

• 1) you collected 3 triggers (audiosources), you begin play 1,2,3. - and stop.

• 2) after 10 seconds you collected 2 more triggers, so it will play : 1,2,3,4,5 - and stop.

  ---

If you want to clear your audisources after playing once, and wait for new triggers, then just uncomment playableAudioSources.Clear(); . And it will like:

• 1) you collected 3 triggers (audiosources), you begin play 1,2,3. - and stop, and delete them from list.

• 2) after 10 seconds you collected 2 more triggers, so it will play : 4,5 - and stop, and delete them from list.

  ---

This will help you :

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class delete : MonoBehaviour
 {
 
     public List<AudioSource> playableAudioSources; // Use List because it is dynamic
     public bool audioPlaying;
 
     void Awake()
     {
         playableAudioSources = new List<AudioSource>();
     }
 
     void OnTriggerEnter(Collider other)
     {
         // checking if trigger has a audiosource, and if we already added it to our list. If added already then it will skip it. Because OnTriggerEnter can be called many times
         if (other.GetComponent<AudioSource>() && !playableAudioSources.Contains(other.GetComponent<AudioSource>()))
         {
             //add to list:
             playableAudioSources.Add(other.GetComponent<AudioSource>());
 
             if (!audioPlaying)
             {
                 audioPlaying = true;
                 StartCoroutine(PlaySounds());
             } 
         }
     }
 
     private IEnumerator PlaySounds()
     {
         // play all audisources one by one, if you will add some new audiosource while playing, it will be added to the end of list and played also
         for (int i = 0; i < playableAudioSources.Count; i++)
         {
             // check if current is not playing
             if (!playableAudioSources[i].isPlaying)
             {
                 playableAudioSources[i].Play();
                 // wait for the end of current audiosource
                 yield return new WaitForSeconds(playableAudioSources[i].clip.length);
             }
         }
 
         //// if you want to clear your audiosources after playing, just use it.
         //playableAudioSources.Clear(); // uncomment me !
 
         // lets say to the game that we finished playing one cicle of audisources, so if we will hit one more trigger, we can play it again
         audioPlaying = false;
 
     }
 }

thanks bakir-omarov! this solution of yours is very nice! I implemented on my current script,it is for SteamVR / HTC Vive. It is attached to the controller. If I press the grip button while ontrigger, I can grab objects. Each grabbed object has the sound played in order (this part all works). When I press the trigger, I release the children (set parent to null again), audio stops but somehow I need to wait (I think) the coroutine to finish the loop before I can properly use it again. Any idea why?

(for some reason it won't load the code as comment but only as answer..)

 using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     
     public class VRControllerInput : MonoBehaviour
     {
     
         protected List<Collectable> heldObjects;
     
         private Valve.VR.EVRButtonId gripButton = Valve.VR.EVRButtonId.k_EButton_Grip;
         private Valve.VR.EVRButtonId triggerButton = Valve.VR.EVRButtonId.k_EButton_SteamVR_Trigger;
         protected SteamVR_TrackedObject trackedObj;
         public SteamVR_Controller.Device device { get { return SteamVR_Controller.Input((int)trackedObj.index); } }
     
     
         public List<AudioSource> playableAudioSources; // Use List because it is dynamic
         public bool audioPlaying;
         public static bool needsToStop;
     
     
         private void Awake()
         {
             trackedObj = GetComponent<SteamVR_TrackedObject>();
             heldObjects = new List<Collectable>();
             playableAudioSources = new List<AudioSource>();
      
         }
     
         private void OnTriggerStay(Collider other)
         {
             Collectable collectable = other.GetComponent<Collectable>();
     
             if (collectable != null)
             {
                 if (device.GetPressDown(gripButton))
                 {
                     collectable.PickUP(this);
                     heldObjects.Add(collectable);
                     needsToStop = false;
     
                     // checking if trigger has a audiosource, and if we already added it to our list. If added already then it will skip it.
                     if (collectable.GetComponent<AudioSource>() && !playableAudioSources.Contains(collectable.GetComponent<AudioSource>()))
                     {
                         //add to list:
                         playableAudioSources.Add(other.GetComponent<AudioSource>());
     
                         if (!audioPlaying)
                         {
                             audioPlaying = true;
     
                             StartCoroutine(PlaySounds());
                             
                         }
                     }
                 }
             }
         }
     
     
         private void Update()
         {
     
             if (heldObjects.Count > 0)
             {
                 if (device.GetPressDown(triggerButton))
                 {
      
                     for (int i = 0; i < heldObjects.Count; i++)
                     {
                         heldObjects[i].Release(this);
                     }
     
                     for (int i = 0; i < playableAudioSources.Count; i++)
                     {
                         playableAudioSources[i].Stop();
                     }
     
                     heldObjects = new List<Collectable>();
                     playableAudioSources = new List<AudioSource>();
                 }
             }
         }
     
         private IEnumerator PlaySounds()
         {
             for (int i = 0; i < playableAudioSources.Count; i++)
             {
                 if (!playableAudioSources[i].isPlaying)
                 {
                     playableAudioSources[i].Play();
                     // wait for the end of current audiosource
                     yield return new WaitForSeconds(playableAudioSources[i].clip.length);
                 }
     
                 //// if you want to clear your audiosources after playing, just use it.
                 //playableAudioSources.Clear(); // uncomment me !
     
                 // lets say to the game that we finished playing one cicle of audisources, so if we will hit one more trigger, we can play it again
                 audioPlaying = false;
             }
         }
     }