How to make enemy attack you on contact?

Question

I am making a fps and I have small robots that "bite" you. this is their code.

 using UnityEngine; using UnityEngine.AI;
 
 
 [RequireComponent(typeof(NavMeshAgent))] [RequireComponent(typeof(Rigidbody))]
 
 public class SC_NPCEnemy : MonoBehaviour, IEntity { public float attackDistance = 3f; public float movementSpeed = 4f; public float npcHP = 30; //How much damage will npc deal to the player public float npcDamage = 5; public float attackRate = 0.5f; public Transform firePoint; public GameObject npcDeadPrefab;
 
  [HideInInspector]
  public Transform playerTransform;
  [HideInInspector]
  public SC_EnemySpawner es;
  NavMeshAgent agent;
  float nextAttackTime = 0;
  Rigidbody r;
  // Start is called before the first frame update
  void Start()
  {
      agent = GetComponent<NavMeshAgent>();
      agent.stoppingDistance = attackDistance;
      agent.speed = movementSpeed;
      r = GetComponent<Rigidbody>();
      r.useGravity = false;
      r.isKinematic = true;
  }
  // Update is called once per frame
  void Update()
  {
      if (agent.remainingDistance - attackDistance < 0.01f)
      {
          if (Time.time > nextAttackTime)
          {
              nextAttackTime = Time.time + attackRate;
              //Attack
              RaycastHit hit;
              if (Physics.Raycast(firePoint.position, firePoint.forward, out hit, attackDistance))
              {
                  if (hit.transform.CompareTag("Player"))
                  {
                      Debug.DrawLine(firePoint.position, firePoint.position + firePoint.forward * attackDistance, Color.cyan);
                      IEntity player = hit.transform.GetComponent<IEntity>();
                      player.ApplyDamage(npcDamage);
                  }
              }
          }
      }
      //Move towardst he player
      agent.destination = playerTransform.position;
      //Always look at player
      transform.LookAt(new Vector3(playerTransform.transform.position.x, transform.position.y, playerTransform.position.z));
      //Gradually reduce rigidbody velocity if the force was applied by the bullet
      r.velocity *= 0.99f;
  }
  public void ApplyDamage(float points)
  {
      npcHP -= points;
      if (npcHP <= 0)
      {
          //Destroy the NPC
          GameObject npcDead = Instantiate(npcDeadPrefab, transform.position, transform.rotation);
          //Slightly bounce the npc dead prefab up
          npcDead.GetComponent<Rigidbody>().velocity = (-(playerTransform.position - transform.position).normalized * 8) + new Vector3(0, 5, 0);
          Destroy(npcDead, 10);
          es.EnemyEliminated(this);
          Destroy(gameObject);
      }
  }
 }
 
 this is the player health
 
 using UnityEngine;
 
 public class SC_DamageReceiver : MonoBehaviour, IEntity { //This script will keep track of player HP public float playerHP = 100; public SC_CharacterController playerController; public SC_WeaponManager weaponManager;
 
  public void ApplyDamage(float points)
  {
      playerHP -= points;
      if (playerHP <= 0)
      {
          //Player is dead
          playerController.canMove = false;
          playerHP = 0;
      }
  }
 }

Thanks in advance! :)

Answer 1

Best Answer

Answer by Llama_w_2Ls · Nov 27, 2020 at 05:43 PM

Please place code in the code block, like this:

 void Start()
 {
     //...
 }

Also, to answer your question, you first need to detect a collision, then reduce the health when a collision event is called.

Collision events are called in the void OnCollisionEnter(Collision collider) method, where the parameter, collider is your collision information. E.g. What you hit, and its properties.

To detect a collision and reduce health, your script should look something like...

 public class Player : MonoBehaviour
 {
     public int health = 100;
 
     void OnCollisionEnter(Collision collisionInfo)
     {
         if (collisionInfo.gameObject.CompareTag("enemy"))
         {
             health -= 10;
         }
     }
 
 }

Remember that a collision only occurs if the object has a rigidbody and a collider, and it hits another object with a collider too. You can use triggers instead of colliders as well by using the void OnTriggerEnter() method. @Sansgamer120

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Sansgamer120 · Nov 28, 2020 at 10:15 PM 0

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thanks, didn't think it was that simple.

Sansgamer120 · Nov 28, 2020 at 11:58 PM 0

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@Llama_w_2Ls What do I attach the script to, the player right, I tried a few variations of your script, but they aren't working, thanks.

Llama_w_2Ls Sansgamer120 · Nov 30, 2020 at 07:11 AM 0

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It's attatched to the player, but the player needs a rigidbody and collider, as well as other objects needing colliders as well. @Sansgamer120

Sansgamer120 Llama_w_2Ls · Nov 30, 2020 at 04:24 PM 0

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@Llama_w_2Ls it is not working for some reason, they both have colliders and rigid bodies, but the enemy just bumps the player and pushes him back. It moves back and forward fast, maybe it is my old script?

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How to make enemy attack you on contact?

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