code: public void vertex(Vector3D v) {
          MODE = LINES_3D;
          this.cornerX.add(v.getX());
          this.cornerY.add(v.getY());
          this.cornerZ.add(v.getZ());
          setNumberOfCorner(this.cornerX.size());
          calcG();
      }
docs: Adds the corner of Polygon.
  
  @param v The coordinates of a new added corner.