Rocket launcher C# problem

Unity Engine
1

Trying to convert my old js script to C#

using UnityEngine;
using System.Collections;

public class Xlauncher : MonoBehaviour {

public Transform rocketPrefab; 
public Transform rocket2Prefab;
public float rocketSpeed = 20; 
public float rocket2Speed = 15;
public Transform spawnPoint; 
public Texture2D crosshairTexture; 
public Rect position; 

//------------------------------------------------------------------------------

private float Attack1nextShoot = 0; 
private float Attack2nextShoot = 0;
public float Attack1fireRate = 1;
public float Attack2fireRate = 1;

//-------------------------------------------------------------------------------
public Vector2 pos = new Vector2(20,40);
public Vector2 size = new Vector2(60,20);

public float time;


void Update () {


	position = new  Rect((Screen.width - crosshairTexture.width) / 2, (Screen.height - crosshairTexture.height) /2, crosshairTexture.width, crosshairTexture.height);

	Ray ray = Camera.main.ViewportPointToRay( new Vector3(0.5f,0.5f,0));
    RaycastHit hit = new RaycastHit();
    Vector3 dir;
  

  if (Input.GetButton("Fire1")  Time.time > Attack1nextShoot){
  	Attack1nextShoot = Time.time + Attack1fireRate;
    if (Physics.Raycast(ray, out hit)){

      dir = (hit.point - spawnPoint.position).normalized;
    }
    else {

      dir = ray.direction; 
    }

    Quaternion rot = Quaternion.FromToRotation(rocketPrefab.forward, dir);

    Rigidbody rocket = Instantiate(rocketPrefab, spawnPoint.position, rot) as Rigidbody;

    rocket.rigidbody.velocity = dir * rocketSpeed;
  }
  else if (Input.GetButtonUp("Fire2")  Time.time > Attack2nextShoot){
  	Attack2nextShoot = Time.time + Attack2fireRate; 		
  	if (Physics.Raycast(ray, out hit)){
     dir = (hit.point - spawnPoint.position).normalized;
    }
    else {
      dir = ray.direction;
    }
    Quaternion rot2 = Quaternion.FromToRotation(rocket2Prefab.forward, dir);
    Rigidbody rocket2 = Instantiate(rocket2Prefab, spawnPoint.position, rot2) as Rigidbody;
    rocket2.rigidbody.velocity = dir * rocket2Speed; 
  }
}

void OnGUI()
	{
		GUI.DrawTexture(position, crosshairTexture);
	}
}

And here is an error I get when trying to fire

NullReferenceException: Object reference not set to an instance of an object
Xlauncher.Update () (at Assets/Scripts/Weapon/Xlauncher.cs:53)

2

Try:

Rigidbody rocket = new Rigidbody();
rocket = Instantiate(rocketPrefab, spawnPoint.position, rot) as Rigidbody;
rocket.rigidbody.velocity = dir * rocketSpeed;
3

same error at line

4

Try this:

GameObject rocketGO = Instantiate(rocketPrefab.gameObject, spawnPoint.position, rot) as GameObject;
rocketGO.rigidbody.velocity = dir * rocketSpeed;
5

I dont think that the rigid body is your problem. dir is. You set up the variable, but never initalize it.

Change line:

Vector3 dir;

to

Vector3 dir = Vector3.forward;