/**
* construct a vector from this point instance.
*/
public function getVector()
{
$vector = new Vector();
$vector->x($this->x());
$vector->y($this->y());
$vector->z($this->z());
return $vector;
}
public static function det(Vector $u, Vector $v, Vector $w)
{
return $u->x() * $v->y() * $w->z() + $u->y() * $v->z() * $w->x() + $u->z() * $v->x() * $w->y() - $u->z() * $v->y() * $w->x() - $u->y() * $v->x() * $w->z() - $u->x() * $v->z() * $w->y();
}
