rabidus-test/Assets/DissolveEffect.cs

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

public class DissolveEffect : MonoBehaviour
{
    List<Renderer> _renderer = new List<Renderer>();

    [SerializeField] private string _param = "_Dissolve";
    [SerializeField] private float _fromValue = 0;
    [SerializeField] private float _toValue = 1;
    [SerializeField] private float _time;

    private bool _action = false;
    private float _timeElapsed = 0;
    private float _currentValue = 0;

    private void Awake()
    {
        _renderer.AddRange(GetComponentsInChildren<Renderer>());
    }

    [ContextMenu("Dissolve")]
    public void Dissolve()
    {
        _action = true;
    }

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

        if (_timeElapsed < _time)
        {
            _currentValue = Mathf.Lerp(_fromValue, _toValue, _timeElapsed / _time);

            for (int i = 0; i < _renderer.Count; i++)
            {
                for (int h = 0; h < _renderer[i].materials.Length; h++)
                {
                    _renderer[i].materials[h].SetFloat(_param, _currentValue);
                }
            }

            _timeElapsed += Time.deltaTime;
        }
    }
}