Collision issues

Questions & Answers
1

I am relatively new to unity, and still learning the ropes. I am trying to make a script to update health on collision (with a dagger, sword, etc.)
I have 2 problems.
1)the dagger I give to my first person controller is not colliding with objects
2)when 2 things collide, the message to run the “hit” method is being lost.

here is my code:
Health script

using UnityEngine;
    using System.Collections;
    
    [System.Serializable]
    public class HealthManager : MonoBehaviour {
    	
    	public int maxHP;
    	public int curHP;
    	
    	void Start(){
    		curHP = maxHP;
    	}
    	
    	void Hit(int dmg){
    		curHP -= dmg;
    		if(curHP <= 0)
    			Death();
    	}
    	
    	void Death(){
    		if(curHP > 0)
    			curHP = 0;
    		Transform.Destroy(this);
    	}
    	
    	void Heal(int hp){
    		curHP += hp;
    		if(curHP > maxHP)
    			curHP = maxHP;
    	}
    }

damage script

using UnityEngine;
using System.Collections;

[System.Serializable]
public class WeaponHandler : MonoBehaviour {
	public int dmg;
	
	// Use this for initialization
	void Start () {
		
	}
	
	// Update is called once per frame
	void Update () {
		if(collider.transform.tag == "Enemy")
			collider.transform.SendMessage("Hit", dmg,SendMessageOptions.DontRequireReceiver);
		else if(collider.transform.tag == "Vital")
			collider.transform.SendMessage("Death", SendMessageOptions.DontRequireReceiver);
		else if(collider.transform.tag == "Armor")
			collider.transform.SendMessage("Damage", dmg/2,SendMessageOptions.DontRequireReceiver);
				
			
	}
}
2

You should move the calls in Update() to one of the collider functions, assuming your objects have colliders.
e.g.

function OnCollisionEnter(col : Collider)
{

}

These functions and Raycast generate hitinfo for your code to interpret.You don’t have anything to generate such info.
If your objects don’t have colliders, add them in to the weapon.

3

After messing with my code and stuff in the scene, I got the error
“SendMessage Hit has no receiver!”

I changed the OnCollisionEnter function to this, just to test it:

 void OnCollisionEnter(){
    		collider.SendMessage("Hit", dmg);
    }

i added a rigid body to my knife, and now it spins in place when it hits something. Not the most effective for a game, but it confirms the collider is working. I can find a better way to do colliders later