can't spawn a model with the same name as a previously-deleted one #510

osrf-migration · 2013-02-19T05:32:20Z

Original report (archived issue) by Jonathan Bohren (Bitbucket: jbohren).

I looked for a ticket corresponding to this kforge ticket, but couldn't find one: https://kforge.ros.org/gazebo/trac/ticket/49

osrf-migration · 2013-02-19T17:22:38Z

Original comment by Steve Peters (Bitbucket: Steven Peters, GitHub: scpeters).

Are you spawning the model using the "Insert" tab on the left side of the screen? In the latest development branch of gazebo, I can verify that the model is successfully deleted from the server (I spawned and deleted some models and then did a "Save world as" and the models were not listed in the saved sdf file). I think the model is not being deleted from the client, which increments the model name in ModelMaker::CreateTheEntity:348-355.

osrf-migration · 2013-02-19T20:25:50Z

Original comment by Jonathan Bohren (Bitbucket: jbohren).

This was in version 1.3, using the ROS service to spawn the model, and the gazebo gui to delete it. Since the server reports no errors, I wouldn't be surprised if it was just a problem with the gui client.

osrf-migration · 2013-02-22T16:02:52Z

Original comment by Nate Koenig (Bitbucket: Nathan Koenig).

changed state from "new" to "on hold"

Until 2.0

osrf-migration · 2013-07-08T22:02:19Z

Original comment by Ian Chen (Bitbucket: Ian Chen, GitHub: iche033).

changed state from "on hold" to "open"

osrf-migration · 2016-01-14T10:37:51Z

Original comment by Silvio Traversaro (Bitbucket: traversaro).

The issue is still present in the latest version of Gazebo.
If I try to spawn from the GUI a robot (let's say named icub), then the robot has name icub

If I then delete it and I respawn it from the GUI, then the robot name will be icub_0. If I delete it and respawn again, its name will be icub_2.

This happens only for model spawned with the GUI.

The cause is that the for the model created by the GUI, the MainWindow::entities data stucture is used to check name duplicates (https://github.com/osrf/gazebo/blob/318d72e43638591f25ba9af15e10b99194e8ec52/gazebo/gui/ModelMaker.cc#L398):

    // Automatically create a new name if the model exists
    rendering::ScenePtr scene = gui::get_active_camera()->GetScene();
    gui::MainWindow *mainWindow = gui::get_main_window();
    if (scene && mainWindow)
    {
      int i = 0;
      while ((isModel && mainWindow->HasEntityName(modelName)) ||
          (isLight && scene->GetLight(modelName)))
      {
        modelName = modelElem->Get<std::string>("name") + "_" +
            std::to_string(i++);
      }
    }

The problem is that the entities data structure is populated on entity creation (see https://github.com/osrf/gazebo/blob/318d72e43638591f25ba9af15e10b99194e8ec52/gazebo/gui/MainWindow.cc#L2022):

void MainWindow::OnModel(ConstModelPtr &_msg)
{
  this->dataPtr->entities[_msg->name()] = _msg->id();
  for (int i = 0; i < _msg->link_size(); i++)
  {
    this->dataPtr->entities[_msg->link(i).name()] = _msg->link(i).id();

    for (int j = 0; j < _msg->link(i).collision_size(); j++)
    {
      this->dataPtr->entities[_msg->link(i).collision(j).name()] =
        _msg->link(i).collision(j).id();
    }
  }

Unfortunately the entities attribute is not cleaned on model removal. As far as I could check, apparently the MainWindow class is not notified by anything on model removal.

osrf-migration · 2016-04-26T20:26:13Z