/// <summary>
/// Add a new bullet at the specified position, rotation and direction
/// </summary>
/// <param name="position">initial position of the new bullet</param>
/// <param name="rotation">rotation of the new bullet</param>
/// <param name="direction">Direction in which the bullet will move</param>
public void AddBullet(Vector3 position,Vector3 rotation, Vector3 direction)
{
Bullet bullet = new Bullet(myGame, Game.Content.Load<Model>("projectile"),
new BulletUnit(myGame, position, rotation, Constants.BULLET_SCALE, direction));
bullets.Add(bullet);
}