How to detect when a new object is spawned or deleted from unity for scoring/points?

Question

I have been trying to make a score/points system for my game where every time an object has been destroyed the score increases, I'm using a set of assets named GDG_Assets which allow you to create destructible environmental objects. when an object is hit the main object is made invisible and a model of the object broken up is spawned in. I want to know how I can detect when these new models have been spawned in and how I can implement them into my code? The "Amount" ints are where the number of objects destroyed/spawned will be stored to give a score. I could detect collision with my projectile but the issue with this is that the way the game is designed an explosion causes a chain reaction causing other objects to be destroyed. any ideas or code improvements would be much appreciated.

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

public class scoreCount : MonoBehaviour {

    public Text countText;



    public int eggCount;
    public int barrelCount;
    public int cubeCount;

    //game objects
    public GameObject Egg_000;
    public GameObject Barrel_000;
    public GameObject Cube01_000;

    //amount of objects destroyed
    public int barrelAmount;
    public int eggAmount;
    public int cubeAmount;

    private int count;
    private int egg;
    private int barrel;
    private int cube;

    // Initializing points of each object
    void Start () {
        count = 0;
        egg = 100;
        barrel = 75;
        cube = 200;
        countText.text = "Score: " + count.ToString ();
    }

    // Update is called once per frame
    void Update () {

        //multiplies amount of objects destroyed by points
        eggCount = egg * eggAmount;
        barrelCount = barrel * barrelAmount;
        cubeCount = cube * cubeAmount;

        //determines final score
        count = eggCount + barrelCount + cubeCount;
        countText.text = "Score: " + count.ToString();
    }
}

Answer 1

You should make that more event driven instead of having it in Update

therefore I would implement an enum.

public enum DestructableType
{
    Egg,
    Barrel,
    Cube,
}

Than I would change your class like

public class scoreCount : MonoBehaviour 
{
    [Header("Components")]
    public Text countText;

    [Header("Prefabs")]
    public DestructableObject Egg_000;
    public DestructableObject Barrel_000;
    public DestructableObject Cube01_000;

    // I didn't see what those are used for
    /*
    public int eggCount;
    public int barrelCount;
    public int cubeCount;
    */

    [Header("amount of objects destroyed")]
    public int barrelAmount;
    public int eggAmount;
    public int cubeAmount;

    // Simply adjust those in the inspector as well and give them default values
    [Header("points values")]
    [SerializeField] private int egg = 100;
    [SerializeField] private int barrel = 75;
    [SerializeField] private int cube = 200;

    // Will be 0 by default anyway
    private int count;

    // Initializing points of each object
    private void Start () 
    {
        // Only thing needed to be set in Start
        // though even this you could simply do in that Text component already
        countText.text = "Score: " + count.ToString ();
    }

    // Called by the DestructableObjects when destroyed
    public void ObjectsDestroyed(DestructableType type)
    {
        // I didn't know which values you really need in the end
        // actually the lines with count += xyz; would be enough I guess
        switch(type)
        {
            case Egg:
                eggCount += egg;
                eggAmount++;
                count += egg;
                break;

            case Barrel:
                barrelCount += barrel;
                barrelAmount++;
                count += barrel;
                break;

            case Cube:
                cubeCount += cube;
                cubeAmount++;
                count += cube;
                break;
        }

        countText.text = "Score: " + count.ToString();
    }
}

And on your Prefabs add an additional component

public class DestructableObject : MonoBehaviour
{
    // Adjust this through the inspector
    public DestructableType Type;

    private void OnDestroy ()
    {
        FindObjectOfType<scoreCount>().ObjectsDestroyed(Type);
    }
}