Drop Shadow helper script

EventEffectHighlightObject.cs

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

public class EventEffectHighlightObject : EventEffect
{
    public Material highlightMaterial;
    public Renderer objectRenderer;

    public Renderer originalObjectRenderer;

    public bool isOriginal = true;

    private void Start()
    {
        if (isOriginal)
        {
            isOriginal = false;
            objectRenderer = this.GetComponent<Renderer>();
            List<Material> mats = new List<Material>();
            for (int i = 0; i < objectRenderer.materials.Length; i++)
            {
                mats.Add(objectRenderer.materials[i]);
            }
        
            if (originalObjectRenderer == null)
            {
                originalObjectRenderer = objectRenderer;
            }
            for (int i = 0; i < originalObjectRenderer.materials.Length; i++)
            {
                originalObjectRenderer.materials[i].SetInt("_stencilRef", 2);
            }

            var go = Instantiate(gameObject, transform);
            go.transform.localScale = new Vector3(1, 1, 1);
            go.transform.localPosition = new Vector3(0, 0, 0);
            go.transform.localRotation = Quaternion.identity;
            objectRenderer = go.GetComponent<Renderer>();

            mats = new List<Material>();
            mats.Add(highlightMaterial);

            objectRenderer.materials = mats.ToArray();
            objectRenderer.materials[^1].SetFloat("_Range", 0);

            var comps = go.GetComponents(typeof(Component));
            foreach (var comp in comps)
            {
                if (!(comp is Transform || comp is MeshFilter || comp is Renderer))
                {
                    Destroy(comp);
                }
            }

            for (int i = 0; i < go.transform.childCount; i++)
            {
                Destroy(go.transform.GetChild(i).gameObject);
            }
        }
    }

    public override void ExecuteEffect()
    {
        objectRenderer.materials[^1].SetFloat("_Range", 1);
    }
    
    public override void LeaveEffect()
    {
        objectRenderer.materials[^1].SetFloat("_Range", 0);
    }
}