riversong-code-showcase/Source/Riversong/Game/Vfx/AutoDestroyVfx.cs

using UnityEngine;
using UnityEngine.VFX;

namespace DanieleMarotta.RiversongCodeShowcase
{
    [RequireComponent(typeof(VisualEffect))]
    public class AutoDestroyVfx : MonoBehaviour
    {
        private const float DestroyDelayWhenNoParticles = 1;

        private VisualEffect _vfx;

        private bool _emittedOnce;

        private float _timer;

        private void Awake()
        {
            _vfx = GetComponent<VisualEffect>();
        }

        private void Update()
        {
            if (!_vfx) return;

            _emittedOnce |= _vfx.aliveParticleCount > 0;
            if (!_emittedOnce) return;

            if (_vfx.aliveParticleCount > 0)
            {
                _timer = 0;
                return;
            }

            _timer += Time.unscaledDeltaTime;

            if (_timer >= DestroyDelayWhenNoParticles) Destroy(gameObject);
        }
    }
}