Multiple arrows with vectors

Hi all,
I'm trying to simulate Volley, a skill of Ashe, LoL Champ, but I have some problems with vectors..

Code:java

@EventHandler
public void Volley(PlayerItemHeldEvent e)
{
Player p = e.getPlayer();
int itemId = e.getNewSlot();
ItemStack is = e.getPlayer().getInventory().getItem(itemId);
if (is.getType().equals(Material.ARROW)){
Location p_loc = p.getLocation();
Vector o = p.getLocation().getDirection();
double x = o.getX();
double y = o.getY();
double z = o.getZ();
double rad = (8*Math.PI)/180;
Vector[] volley = {new Vector(x+rad,y,z), new Vector(x,y,z), new Vector(x,y,z+rad), new Vector(x+rad*2,y,z), new Vector(x,y,z+rad*2)};
for(Vector v : volley) {
p.launchProjectile(Arrow.class).setVelocity(v);
}
}
}

The distance between an arrow and another has to be 8°, so I calculated the radian of it and added to the player X,Y,Z vectorial coordinates.
This works, but works only if I am on -132 jaw approximately: at that angle, the arrows keep the 8° distance.
If I face another direction doesn't work anymore, giving me strange distances (except the x,y,z vector, obviously) and I can't understand why..
I started goniometry a few days ago, so I'm not so skilled on it, forgive me :/

 

I am doing something similiar in one of my plugins:

Code:java

 
// rotate vector "dir" "angleD" degree on the x-z-(2D)-plane
public static Vector rotateYAxis(Vector dir, double angleD) {
    double angleR = Math.toRadians(angleD);
    double x = dir.getX();
    double z = dir.getZ();
    double cos = Math.cos(angleR);
    double sin = Math.sin(angleR);
    return (new Vector(x*cos+z*(-sin), 0.0, x*sin+z*cos)).normalize();
}
 

I am using this in a to shoot snowballs in different angles:

Code:java

 
// some angles in degree:
private int[] angles = {angle2, angle1, 0, -angle1, -angle2}:
 
// the shooting player, his eyelocation, his view direction (player.getEyeLocation().getDirection()) and the speed of the spawned snowball:
public void shoot(Player player, Location location, Vector direction, double speed) {
    // making sure that the vector is length 1
    direction.normalize();
    // some trick, to get a vector pointing in the player's view direction, but on the x-z-plane only and without problems when looking straight up (x, z = 0 then)
    Vector dirY = (new Location(location.getWorld(), 0, 0, 0, location.getYaw(), 0)).getDirection().normalize();
    for (int angle : angles) {
        Vector vec;
        if (angle != 0) {
            vec = Utils.rotateYAxis(dirY, angle);
            vec.multiply(Math.sqrt(vec.getX() * vec.getX() + vec.getZ() * vec.getZ())).subtract(dirY);
            vec = direction.clone().add(vec).normalize();
        } else {
            vec = direction.clone();
        }
        Snowball snowball = location.getWorld().spawn(location, Snowball.class);
        snowball.setShooter(player);
        snowball.setVelocity(vec.clone().multiply(speed));
    }
}
 

So you just need to fill in the angles and replace the snowballs with arrows.

 

blablubbabc: You made my day, thanks so much, it works!