Transform instantiated bullet towards camera center

Question

I have made a very simple gun script, currently the bullet transform in the same direction as the GameObject i have set as the bullet spawn position. but i want the bullet to transform towards the center of the camera, i have a couple of different ideas. The 1st one is shooting a raycast when the raycast hit something transform the bullet form bulletpos to raycasthit position. But i dont quite know how to do this, can anyone help me?

Here is my script:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Gun : MonoBehaviour {

    public Transform bulletCapTransform;
    public GameObject bulletCap;

    public float ammo;
    public float magAmmo;

    public GameObject shootEffect;
    public Transform bulletTransform;
    public GameObject bullet;
    public float bulletForce;

    public GameObject crossHair;

    public float fireRate = 0.3333f;
    private float timeStamp;

    Animator anim;

    // Use this for initialization
    void Start ()
    {
        anim = gameObject.GetComponent<Animator>();
    }

    // Update is called once per frame
    void Update ()
    {
        Shoot();
        Aim();
    }

    public void OnGUI()
    {
        GUI.Box(new Rect(10, 10, 50, 25), magAmmo + " / " + ammo);
    }

    public void Shoot()
    {
        if(Time.time >= timeStamp && Input.GetButton("Fire1") && magAmmo > 0)
        {
            GameObject bulletCapInstance;
            bulletCapInstance = Instantiate(bulletCap, bulletCapTransform.transform.position, bulletCapTransform.rotation) as GameObject;
            bulletCapInstance.GetComponent<Rigidbody>().AddForce(bulletCapTransform.right *10000);

            GameObject bulletInstance;
            bulletInstance = Instantiate(bullet, bulletTransform) as GameObject;
            bulletInstance.GetComponent<Rigidbody>().AddForce(bulletTransform.forward * bulletForce);

            Instantiate(shootEffect, bulletTransform);

            timeStamp = Time.time + fireRate;

            magAmmo = magAmmo -1;
        }

        if(Input.GetKeyDown(KeyCode.R))
        {
            //This is just for testing
            magAmmo = magAmmo + 10;
        }
    }

    void Aim()
    {
        if(Input.GetButton("Fire2"))
        {
            anim.SetBool("Aiming", true);
            crossHair.SetActive(false);
        }
        else
        {
            anim.SetBool("Aiming", false);
            crossHair.SetActive(true);
        }
    }
}

Answer 1

So i think you want to fire a projectile from a "gun" object towards whatever is at the centre of your screen (regardless of central objects distance)

This script is working for me and shoots dead into the centre of the view.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Gun : MonoBehaviour
{

public Transform bulletCapTransform;
public GameObject bulletCap;

public float ammo;
public float magAmmo;

public GameObject shootEffect;
public Transform bulletTransform;
public GameObject bullet;
public float bulletForce;

public GameObject crossHair;

public float fireRate = 0.3333f;
private float timeStamp;

Animator anim;

// Use this for initialization
void Start()
{
    anim = gameObject.GetComponent<Animator>();
}

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

   Shoot();
   Aim();

}

public void OnGUI()
{
    GUI.Box(new Rect(10, 10, 50, 25), magAmmo + " / " + ammo);
}

public void Shoot()
{
    if (Time.time >= timeStamp && Input.GetButton("Fire1") && magAmmo > 0)
    {
        Debug.Log("shoot");
        GameObject bulletCapInstance;
        bulletCapInstance = Instantiate(bulletCap, bulletCapTransform.transform.position, bulletCapTransform.rotation) as GameObject;
        bulletCapInstance.GetComponent<Rigidbody>().AddForce(bulletCapTransform.right * 10000);


        //This will send a raycast straight forward from your camera centre.
        Ray ray = Camera.main.ViewportPointToRay(new Vector3(0.5f, 0.5f, 0));
        RaycastHit hit;
        //check for a hit
        if (Physics.Raycast(ray, out hit))
        {
            // take the point of collision (make sure all objects have a collider)
            Vector3 colisionPoint = hit.point;

            //Create a vector for the path of the bullet from the 'gun' to the target
            Vector3 bulletVector = colisionPoint - bullet.transform.position;

            GameObject bulletInstance = Instantiate(bullet, bulletTransform) as GameObject;

            //See it on it's way
            bulletInstance.GetComponent<Rigidbody>().AddForce(bulletVector * bulletForce);

        }


        Instantiate(shootEffect, bulletTransform);

        timeStamp = Time.time + fireRate;

        magAmmo = magAmmo - 1;
    }

    if (Input.GetKeyDown(KeyCode.R))
    {
        //This is just for testing
        magAmmo = magAmmo + 10;
    }
}

void Aim()
{
    if (Input.GetButton("Fire2"))
    {
        anim.SetBool("Aiming", true);
        crossHair.SetActive(false);
    }
    else
    {
        anim.SetBool("Aiming", false);
        crossHair.SetActive(true);
    }
}
}

The crucial point to remember is this:

Camera.main.ViewportPointToRay(0.5, 0.5, 0);

Will shoot a raycast dead ahead from the centre of your screen.

It's worth really getting to know raycasting and it's ins and outs. it seems daunting at first but its so useful once you've got it down and it's pretty intuitive. There are a lot of good youtube tutorials.

Hope your game turns out good!