void
Skin0::setVisible( ArRef<Scene3D> scene, bool visible)
{
if (_visible && !visible)
  {
  for (unsigned int i(0);i<_objects.size();++i)
    { scene->removeObject(_objects[i]); }
  _visible = false;
  }
else if (!_visible && visible)
  {
  for (unsigned int i(0);i<_objects.size();++i)
    { scene->addObject(_objects[i]); }
  _visible = true;
  }
}