or_rviz

or_rviz is an OpenRAVE plugin that provides two ROS-friendly OpenRAVE viewers that publish an OpenRAVE environment as interactive markers to be visualized in RViz. See below for more information.

Installation

⚠️ Note: The version of interactive_markers shipped with versions of ROS before indigo (e.g. groovy and hydro) have a known issue that will cause OpenRAVE to SEGFAULT when the viewer is created. This issue is fixed in a pull request, but has not propagated to the official ROS Debian packages. If you are using ROS Groovy or Hydro, you must checkout and build the indigo-devel branch of interactive_markers.

or_rviz is a ROS package that can be installed into any ROS Catkin workspace. It requires the helper package openrave_catkin to be automatically added to the OPENRAVE_PLUGIN path.

You can try running rosrun or_rviz test.py to test your installation. This script loads the wamtest1.env.xml environment, which is one of the default environments shipped with OpenRAVE, into the RViz in-process viewer.

Usage: Out-of-Process Viewer

The InteractiveMarker viewer publishes the environment to a specified topic to be visualized by an external RViz process. As a result, this viewer is extremely lightweight and adds negligibly to the OpenRVE startup time. Since rendering occurs in a separate process, some of methods exposed by the OpenRAVE ViewerBase interface are not supported.

Once an OpenRAVE environment env is created, you can attach the InteractiveMarker publisher to it using the following command:

env.SetViewer('InteractiveMarker')

This will publish the OpenRAVE environment env as interactive markers on the openrave ROS namespace. You can view these markers in RViz by opening an external RViz instance (e.g. rosrun rviz rviz) and creating an InteractiveMarkers display component that subscribes to the /openrave/update topic. Note that you must manually create and enable this display component to view the OpenRAVE environment.

Note that a ROS core must be running for the viewer to function. Additionally, the following ViewerBase methods are not implemented when running with an out-of-process RViz instance:

• SetBkgndColor, SetSize, and Move
• GetName and SetName
• SetCamera, GetCameraTransform, and GetCameraIntrinsics
• GetCameraImage and RegisterViewerImageCallback

Usage: In-Process Viewer

The RViz viewer uses librviz and Qt to instantiate RViz in the same process as OpenRAVE. This RViz instance is automatically configured to display the OpenRAVE environment and supports the full range of methods exposed by the ViewerBase interface. Additionally, the RViz viewer allows you to interact with the OpenRAVE environment through a custom RViz display plugin; e.g. to change which OpenRAVE environment is being displayed, and to load additional OpenRAVE environments and objects.

Once an OpenRAVE environment env is created, you can attach an in-process viewer to it using the following command:

env.SetViewer('RViz')

This will open an RViz window and automatically create two display components:

1. An "OpenRAVE Markers" InteractiveMarker display that is subscribing to an automatically generated topic name.
2. An "OpenRAVE Environment" custom display with a few configuration options:
   • Mapping between the OpenRAVE "world frame" and a TF frame (default: the fixed frame in RViz)
   • Current environment being displayed (default: environment with the lowest ID when the viewer is created)
   • List of KinBodys and Robots in the environment

Note that a ROS core must be running for the viewer to function. This is unfortunate, because both OpenRAVE and the RViz window are running in the same process. Unfortunately, this is a fundamental limitation inherited from the design of librviz.

The following methods are implemented, but have not yet been fully tested:

• GetCameraTransform, and GetCameraIntrinsics
• GetCameraImage and RegisterViewerImageCallback

The following functions are unimplemented:

• SetCamera (due to an internal limitation of librviz)

Brief Overview of Features

or_rviz publishes a separate InteractiveMarker for each of a robot's links. You can right click on any link of a robot to access the following functionality:

• Link
  • Enable/disable collision checking
  • Enable/disable visibility
  • View collision, render, or both types of geometry
  • Change the active geometry group
• KinBody or Robot
  • Enable/disable handles to move the body's 6-DOF pose
  • Enable/disable handles to rotate the body's joints (Note: only revolute joints are supported)
  • Perform any actions on Link to the entire body at once
• Manipulator
  • Set as the active manipulator
  • Enable/disable a "ghost manipulator" that attempts to follow an inverse kinematics target
    • The ghost manipulator is green by default and turns red if no IK solution exists for the current handle location
    • Joint handles are attached to the ghost manipulator's free joints to allow you to adjust the configuration of the manipulator in the null space (Note: this feature has not been thoroughly tested
    • Right click on the ghost manipulator to:
      • Snap the robot's manipulator to the configuration of the ghost manipulator
      • Snap the ghost manipulator to the current configuration of the robot's manipulator
    • Note: All of this functionality is only implemented IK solvers with the Transform6D IK parameterization type

Frequently Asked Questions

You may get the following error message when running a standalone RViz instance after using the in-process viewer:

[ERROR] PluginlibFactory: The plugin for class 'or_rviz::rviz::EnvironmentDisplay' failed to load. Error: Could not find library corresponding to plugin or_rviz::rviz::EnvironmentDisplay. Make sure the plugin description XML file has the correct name of the library and that the library actually exists.

This occurs if save your RViz configuration (i.e. .vcg file) from the in-process RViz viewer, then load it in a standalone RViz process. This configuration contains a custom OpenRAVE EnvironmentDisplay component that can only be constructed when running in the same process as OpenRAVE. You can prevent this error from printing in the future by deleting the offending EnvironmentDisplay component from RViz and re-saving your configuration.

We are interested in finding a more elegant workaround for this problem. Please open an issue or send us a pull request if you have any suggestions.

License

or_rviz is licensed under a BSD license. See LICENSE for more information.

Contributors

or_rviz is developed by the Personal Robotics Lab in the Robotics Institute at Carnegie Mellon University. The out-of-process InteractiveMarker viewer was originally developed by Michael Koval and the in-process RViz viewer was originally developed by Matt Klingensmith.

This is a non-exhaustive list of contributors:

• Michael Koval
• Matt Klingensmith
• Pras Velagapudi
• Jen King