isaac_ros_nitros

Source code on GitHub.

Quickstart

Creating Graphs with NITROS-Accelerated Nodes

Besides the fully tested graphs, it is also possible to construct your own graphs with any of the Isaac ROS NITROS-accelerated nodes to enjoy the performance benefit of NITROS.

The key to successfully constructing a NITROS-accelerated graph is to ensure that all NITROS-accelerated nodes start in the same process (which permits zero-copy between nodes). To do so, follow the steps below to create your own launch file:

1. Create a Python ROS 2 launch file following the official guide.

2. Create NITROS-accelerated nodes using ComposableNode. Taking ArgusMonoNode and RectifyNode as an example, the nodes can be created as follows:

   argus_mono_node = ComposableNode(
       name='argus_mono_node',
       package='isaac_ros_argus_camera',
       plugin='nvidia::isaac_ros::argus::ArgusMonoNode',
   )
   
   rectify_node = ComposableNode(
       name='rectify_node',
       package='isaac_ros_image_proc',
       plugin='nvidia::isaac_ros::image_proc::RectifyNode',
       parameters=[{
           'output_width': 1920,
           'output_height': 1200,
       }],
       remapping=[
           ('image_raw', 'left/image_raw'),
           ('camera_info', 'left/camerainfo')
       ],
   )
   

3. Place the created nodes in ComposableNodeContainer:

   nitros_container = ComposableNodeContainer(
       name='nitros_container',
       package='rclcpp_components',
       executable='component_container_mt',
       composable_node_descriptions=[argus_mono_node, rectify_node],
   )
   

   Note: It is crucial that the executable field is set to be component_container_mt so that the created nodes can be started and communicated correctly within the same process.

4. Finally, place the created composable node container in LaunchDescription to finalize the launch script.

   return launch.LaunchDescription([nitros_container])
   

Using NITROS-Accelerated Nodes in Existing Non-NITROS Graphs

It is also possible to use any NITROS-accelerated nodes in an existing ROS 2 graph, as all Isaac ROS nodes are compatible with non-NITROS ROS 2 nodes.

Follow these steps to integrate one or more NITROS-accelerated nodes into your graph:

1. Follow the same steps introduced in the previous section to create a ComposableNodeContainer that contains all the NITROS-accelerated nodes with multi-thread enabled (i.e. executable='component_container_mt').

2. Place the created composable node container in LaunchDescription together with your own, regular ROS 2 node or composable node container declarations.

Now the NITROS-accelerated nodes will be able to choose the best compatible way to communicate with their adjacent nodes.

• When connected to non-NITROS nodes, NITROS-accelerated nodes will function like regular ROS 2 nodes.

• When connected to NITROS-accelerated nodes, zero-copy data transmission via type adaptation and type negotiation will be adopted.

Please visit the link below for an example graph that consists of NITROS-accelerated and non-NITROS nodes:

• NITROS-accelerated AprilTag node + non-NITROS USB camera node