public void renderSelection(Rendering rendering, boolean hovered) {
    if (indoors() || ! inWorld()) return ;
    final boolean t = aboard() instanceof Tile ;
    Selection.renderPlane(
      rendering, viewPosition(null), (radius() + 0.5f) * (t ? 1 : 0.5f),
      Colour.transparency((hovered ? 0.5f : 1.0f) * (t ? 1 : 0.5f)),
      Selection.SELECT_CIRCLE
    ) ;
  }