Firing projectile in the Z direction.

Unity Engine
1

I am trying to make a top down game and I have a projectile firing from the player however I cant seem to get it to work correctly. It works only some of the time… If I move around and shoot it sometimes goes different directions. Here is my Scipt:

using UnityEngine;
using System.Collections;

public class BouncyBall : MonoBehaviour {

    public Rigidbody BouncyBallPrefab;
    private Transform ballTransform;
    public float Speed;

    void Start()
    {        
        ballTransform = transform;
    }
	
	// Update is called once per frame
	void Update () 
    {
        if (Input.GetKeyDown("left ctrl"))
        {
            Rigidbody instantiatedBouncyBallPrefab = (Rigidbody)Instantiate(BouncyBallPrefab, transform.position, transform.rotation);
            instantiatedBouncyBallPrefab.velocity = new Vector3(transform.position.x, transform.position.y, Speed) ;

        }
	}
}
2

I’m guessing that the player and the projectile collides when you shoot.

Either instantiate the projectile a bit away from the player, or use IgnoreCollisions to make the projectile go through the player.

3

When you’re setting the velocity of the ball, why are you using the transform coordinates for the x and y components? For a projectile’s velocity, if you only want it moving forward, you would only need to set the z component. x and y values are going to interfere with that.

4

both valid replies. I believe my problem is that i am colliding with the projectile… i will try that…

Should I be using quantian.identity then? Not sure how I would proved the vector 3 with anything else…

5 
instantiatedBouncyBallPrefab.velocity = new Vector3(transform.position.x, transform.position.y, Speed) ;

It should be just like this line;

instantiatedBouncyBallPrefab.velocity.z = Speed;
6

You were both right… Thanks for the help guys! Also moving my central ground location from center at 0 to top left corner at 0, 0 helped also.

7

Tried that before… gives me a conversion error… this works:

instantiatedBouncyBallPrefab.velocity = transform.TransformDirection(0, 0, transform.position.z * Speed);