koobas.hobune.stream
Getting Bullets to fire in Direction of Gun Barrel
I am making a game which involves two turrets which rotate 360 degrees and fire when I press the space bar. I am stuck with making the bullets actually fire in the direction the turret is facing. I am trying to get the rotation from the parent object of the turret because that part that actually swivels. When I am running the game and I rotate the turrets using the keyboard it is the pivot (the parent object of the turret) y-axis which changes. I need to find a way to get the rotation of the y-axis and have the bullet fire in that direction. The way I am currently trying to get the rotation is leaving me with numbers which are barely above zero (might as well be zero) even though I can see in the inspector that the y value is changing so obviously I am grabbing the wrong value.
using UnityEngine;
using System.Collections;
public class TurretScript : MonoBehaviour {
public Rigidbody2D Bullet;
public float bulletSpeed = .01f;
private float turretRotationSpeed = 5f;
void Update () {
if(Input.GetKey(KeyCode.S) && gameObject.tag == "T1")
counterClockwise();
if(Input.GetKey(KeyCode.J) && gameObject.tag == "T2")
counterClockwise();
if (Input.GetKey (KeyCode.F) && gameObject.tag == "T1")
clockwise ();
if (Input.GetKey (KeyCode.L) && gameObject.tag == "T2")
clockwise ();
if (Input.GetKey (KeyCode.Space)) {
fire ();
}
}
fire(){
Rigidbody2D newBullet = (Rigidbody2D) Instantiate(Bullet, transform.GetChild(0).position, transform.rotation);
float xDir = transform.parent.rotation.x;
float yDir = transform.parent.rotation.y;
Debug.Log (xDir + " " + yDir);
Vector2 force = new Vector2 (xDir * bulletSpeed, yDir * bulletSpeed);
newBullet.AddForce(force);}
}
You could put an empty game object child of the rotating part of your turret. Place its local position at the tip of the cannon and add a reference to this gameObject's transform from your turret script.
Make sure the zAxis of the transform is pointing towards the direction you want the bullet to go when fired and then, spawn bullets at this location and add use the empty gameObject's transform.forward to know which way to shoot.
Here's a script example
using UnityEngine;
public class Bullet : MonoBehaviour {
public float speed;
public Vector3 direction;
private void Update () {
transform.position += direction * speed * Time.deltaTime;
}
}
public class Turret : MonoBehaviour {
public Transform bulletSpawnT;
public Bullet bulletPrefab;
private void Update () {
if(Input.GetKeyDown (KeyCode.Space)) {
FireBullet();
}
}
private void FireBullet () {
Bullet newBullet = (Bullet)(Instantiate (bulletPrefab,bulletSpawnT, Quaternion.identity) as GameObject);
newBullet.direction = bulletSpawnT.forward;
}
}
I've just realized you're using RigidBody2D, so my bullet's update isn't appropriate, but I guess you'll be able to figure out by yourself the AddForce part of the problem.
I do actually have an empty game object attached to the end of the turret. I had to do that so that the bullets would spawn at the end of the gun ins$$anonymous$$d of halfway down the barrel. It is the GetChild of Rigidbody2D newBullet = (Rigidbody2D) Instantiate(Bullet, transform.GetChild(0).position, transform.rotation);
However, its rotation does not change when I move the gun and am watching it in the inspector. The only rotation that changes is that of the pivot.
The rotation you see in the inspector is in local space i.e. its rotation according to its parent. If the transform is a child of the turret, it is normal that its rotation stays the same even when the turret's rotation change.
If the transform is setup as I mentioned in my answer, you just have to send a force towards the transform's forward direction by using transform.forward
