protected boolean updateForItSelf() {

    Renderer renderer = getView3D().getRenderer();

    PlotterSurface surface;

    surface = renderer.getGeometryManager().getSurface();
    surface.start(this);
    // number of vertices depends on point size
    int nb = 2 + ((GeoPointND) getGeoElement()).getPointSize();
    surface.setU((float) getMinParameter(0), (float) getMaxParameter(0));
    surface.setNbU(2 * nb);
    surface.setV((float) getMinParameter(1), (float) getMaxParameter(1));
    surface.setNbV(nb);
    surface.draw();
    setGeometryIndex(surface.end());

    return true;
  }
  public void drawGeometry(Renderer renderer) {

    renderer.getGeometryManager().draw(getGeometryIndex());
  }