Help me fix this basic HP script

[mradamw]

I’m working on a basic HP script (copying the one found in this video - Unity 3d: Simple First-Person Shooter Tutorial - Part 7 - YouTube - just with some modified names). However, when I’m in game the object I shoot isn’t being destroyed once it’s taken ‘lethal’ damage.

Here is the HasHealth.cs snippet:

using UnityEngine;
using System.Collections;

public class HasHealth : MonoBehaviour {

	public float objectHitPoints = 100f;

	public void receiveDamage (float damageAmount) {
		// Decrement the HP each time damage is taken
		objectHitPoints -= damageAmount;
		// When the object has no more HP...
		if (objectHitPoints <= 0) {
			Die();
		}

	}

	void Die (){
		Destroy (gameObject);
	}

}

and here is the excerpt from my Player_Shoots.cs file.

using UnityEngine;
using System.Collections;

public class Player_Shoots : MonoBehaviour {
	
	public float damage = 50f;
	public GameObject bulletPrefab;

	// Use this for initialization
	void Start () {

	}

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

		if (Input.GetMouseButtonDown (0) && clipSize > 0) {
			Ray ray = new Ray(Camera.main.transform.position, Camera.main.transform.forward);
			RaycastHit hitInfo;

			// Raycast to detect hits
			if(Physics.Raycast(ray, out hitInfo)){
				Vector3 hitPoint = hitInfo.point;

				// Deal damage to target, IF it has health
				HasHealth h = gameObject.GetComponent<HasHealth>();

				if (h != null) {
					h.receiveDamage(damage);
				}

				// Instantiate our bullet at the hitPoint
				if(bulletPrefab != null){
					GameObject bullet = (GameObject)Instantiate(bulletPrefab, hitPoint, Camera.main.transform.rotation);
					bullet.rigidbody.AddForce(0, 400 , 0);
				}
			}
		}
	}
}

I’ve also attached a screenshot of the Inspector panel of my target cube - the object that should be destroyed once shot twice.

[33664-screen+shot+2014-10-14+at+11.23.18.png|33664]

[Landern]

If Player_Shoots.cs is attached to your player and HasHealth.cs is attached to the cube(what the player object is firing at), then your code is trying to get your HasHealth.cs from the player and not the gameobject the raycast it.

Current update with possible issue:

 void Update () {
 
        if (Input.GetMouseButtonDown (0) && clipSize > 0) {
            Ray ray = new Ray(Camera.main.transform.position, Camera.main.transform.forward);
            RaycastHit hitInfo;
 
            // Raycast to detect hits
            if(Physics.Raycast(ray, out hitInfo)){
                Vector3 hitPoint = hitInfo.point;
 
                // Deal damage to target, IF it has health
                HasHealth h = gameObject.GetComponent<HasHealth>(); //<-- Your problem, gameObject refers to the gameObject that this is attached to.
 
                if (h != null) {
                    h.receiveDamage(damage);
                }
 
                // Instantiate our bullet at the hitPoint
                if(bulletPrefab != null){
                    GameObject bullet = (GameObject)Instantiate(bulletPrefab, hitPoint, Camera.main.transform.rotation);
                    bullet.rigidbody.AddForce(0, 400 , 0);
                }
            }
        }
    }

Make sure you’re referencing the gameobject that was hit that has the HasHealth script attached. I’m basing this off the screen shot you included and making assumptions:

 void Update () {
 
        if (Input.GetMouseButtonDown (0) && clipSize > 0) {
            Ray ray = new Ray(Camera.main.transform.position, Camera.main.transform.forward);
            RaycastHit hitInfo;
 
            // Raycast to detect hits
            if(Physics.Raycast(ray, out hitInfo)){
                Vector3 hitPoint = hitInfo.point;
 
                // Deal damage to target, IF it has health
                HasHealth h = hitInfo.collider.gameObject.GetComponent<HasHealth>();
 
                if (h != null) {
                    h.receiveDamage(damage);
                } else {
                    Debug.Log("Couldn't Get HasHealth Script after raycast hit");
                }

 
                // Instantiate our bullet at the hitPoint
                if(bulletPrefab != null){
                    GameObject bullet = (GameObject)Instantiate(bulletPrefab, hitPoint, Camera.main.transform.rotation);
                    bullet.rigidbody.AddForce(0, 400 , 0);
                }
            }
        }
    }

Also adding some Debug.Log statements can help you narrow thing down a bit. I added one just in case HasHealth couldn’t be found.