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how to apply damage to enemy when it collides with particle
i am making an explosion that does damage. I don't know how how to do it. I was thinking that if the explosion touches a tag for the enemy called "enemy" it would apply the script. here is the enemy script. 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 = 100;
//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);
}
}
}
here's the bullet script that does damage.
using System.Collections;
using UnityEngine;
public class SC_Bullet : MonoBehaviour
{
public float bulletSpeed = 345;
public float hitForce = 50f;
public float destroyAfter = 3.5f;
float currentTime = 0;
Vector3 newPos;
Vector3 oldPos;
bool hasHit = false;
float damagePoints;
// Start is called before the first frame update
IEnumerator Start()
{
newPos = transform.position;
oldPos = newPos;
while (currentTime < destroyAfter && !hasHit)
{
Vector3 velocity = transform.forward * bulletSpeed;
newPos += velocity * Time.deltaTime;
Vector3 direction = newPos - oldPos;
float distance = direction.magnitude;
RaycastHit hit;
// Check if we hit anything on the way
if (Physics.Raycast(oldPos, direction, out hit, distance))
{
if (hit.rigidbody != null)
{
hit.rigidbody.AddForce(direction * hitForce);
IEntity npc = hit.transform.GetComponent<IEntity>();
if (npc != null)
{
//Apply damage to NPC
npc.ApplyDamage(damagePoints);
}
}
newPos = hit.point; //Adjust new position
StartCoroutine(DestroyBullet());
}
currentTime += Time.deltaTime;
yield return new WaitForFixedUpdate();
transform.position = newPos;
oldPos = newPos;
}
if (!hasHit)
{
StartCoroutine(DestroyBullet());
}
}
IEnumerator DestroyBullet()
{
hasHit = true;
yield return new WaitForSeconds(0.5f);
Destroy(gameObject);
}
//Set how much damage this bullet will deal
public void SetDamage(float points)
{
damagePoints = points;
}
}
thanks in advance :)
Answer by ddooms · Jan 06, 2021 at 03:18 AM
Don't think of it as collision. Calculating physics on particles leads to poor performance, in my experience. Instead, use multiplication to calculate a distance from each particle to the thing you're wanting to collide with. Have a dedicated transform on the object to use as the location of the enemy. Then, use a distance from the particle to the object with an offset to decided if it had collided. So the vectors might look like this: Float distfromparticletoenemy = (enemypos - particle.position).sqrMagnitude Note that the distance to this would be squared, so you'll need to square the value that is the range you're checking for. Just multiply it by itself. If you want a distance of 3 to be a hit, then that distance would end up being translated 9 instead.
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