Unity ParticleSystem Play and Stop

Question

My particlesystem.Play() does not work. I have spent few hours on this issue and still could not figure out.

Whenever my character hits an object, it will call the function particleAuraPlay(), and the log message "HIT" is showing which means the function is being called properly.

When the playAura is set to true, the particle should play, and again the log message "Running" is showing up, too. Since the message is showing I assume my logic is correct but the particle just won't start playing. Can anyone please solve my problem?

using UnityEngine;
using System.Collections;

public class ParticleController : MonoBehaviour {

    private bool playAura = false;
    private ParticleSystem particleObject;

    void Start () {
        particleObject = GetComponent<ParticleSystem>();
        particleObject.Stop();
    }


    void Update () {
        if (playAura)
        {
            Debug.Log("Running");
            particleObject.Play();
        }

    }

    public void particleAuraPlay()
    {
        Debug.Log("HIT");
        playAura = true;
    }
}

Solution 1

In your particleAuraPlay() function you just need to check if your ParicleSystem is running or not you can achieve this by this code...

 public void particleAuraPlay(){
      if(!particleObject.isPlaying){
          particleObject.Play();
       }     
    }

Solution 2

When the playAura is set to true, the particle should play, and again the log message "Running" is showing up, too. Since the message is showing I assume my logic is correct but the particle just won't start playing

The is a logic error.

When the particleAuraPlay() function is called, playAura is set to true.

In the Update functions,particleObject.Play(); will be called every frame since playAura is true.

You can't do this. Calling particleObject.Play(); every frame will not actually do anything as it will attempt to play and stop particles in each frame resulting to no particles at-all.

The solution is to check if playAura is true, if true, call the particleObject.Play(); function then set playAura to false so that the particleObject.Play(); function won't be called again until particleAuraPlay() is called again.

The new Update() function fixes the logic error:

void Update()
{
    if (playAura)
    {
        Debug.Log("Running");
        particleObject.Play();
        playAura = false;
    }
}

Comments

[user1169079]

Logic seems to be correct ... Check your particlesystem object is active or no ... and check the layer on which is drawn or position ?

[Absinthe]

@ bubibu - Are you sure the particle system is in the right place? I've had problems before where I forgot to parent it, or I used the wrong coordinate system. Also, I wouldn't call Play in Update, just call it once.

[bubibu]

Hi Thanks for response. I pretty sure it is in the right place because if I exclude the line particleObject.Stop(), the particle will start playing.

[Kardux]

Maybe you could try to disable PlayOnAwake property of your particle system. Also, if your particle effect is composed of many particle systems (more than one parented as children of particleObject), you can call particleObject.Play(true);

[Andrea]

Can you try with if (!particleObject.isPlaying) particleObject.Play(); ? My thought is that, being the execution in Update(), the animation starts from the beginning at each frame, limiting the particles from spreading and causing the overall effect to be static. It's just a try, though.

[Programmer]

@bubibu Did you try the solution?

[bubibu]

Hi I have tried out all of the solution given but none of them works.

[bubibu]

Hi guys I have solved the problem! Instead of GetComponent<ParticleSystem>, just changed it to GetComponentInChildren and everything works fine! Thanks everyone for helping!