src/Misc/Coordinate3D.php
public static function fromPolar($length, $ap, $av)
  {
    return new static($length * cos($ap) * cos($av), $length * sin($ap) * cos($av), $length * sin($av));
  }
public static function fromPolar($length, $ap, $av)
  {
    return new static($length * cos($ap) * cos($av), $length * sin($ap) * cos($av), $length * sin($av));
  }
Construct coordinate by the vector length and direction.

@param $length the vector length
@param $ap angle in XY plane (in radians)
@param $av angle off XY plane (in radians)