Unity 3D Game Dev Day 3:how to use onCollisionEnter to change the material of the object,how to change using serilizedfiled to have multiple material drag-ed in, and change according to onCollisioEnter?

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

public class OnCollisionChangeMat : MonoBehaviour
{
    [SerializeField]
    private Material[] materials;

    private int currentMatIndex = 0;

    private Renderer renderer;

    void Start()
    {
        renderer = GetComponent<Renderer>();
    }

    void OnCollisionEnter(Collision collision)
    {
        if (materials.Length > 0)
        {
            renderer.material = materials[currentMatIndex];

            currentMatIndex = (currentMatIndex + 1) % materials.Length;
        }
    }
}

Then you can make multiple materials and leter drag into the list.