for(vector<MObject>::iterator i=objects.begin(); i!=objects.end(); ++i)
i->object->set_position(Vector(center.x+i->pos.x, center.y+i->pos.y, center.z+i->pos.z+dz));
for(vector<MObject>::iterator i=objects.begin(); i!=objects.end(); ++i)
i->object->set_position(Vector(center.x+i->pos.x, center.y+i->pos.y, center.z+i->pos.z+dz));