7.1.14. April Tags

7.1.14.1. Learning Objectives

In this example, we show how to detect April Tags in a scene.

7.1.14.2. Getting Started

Prerequisites

7.1.14.3. Detect April Tags

  • Open the April Tag example by going to Isaac Examples -> ROS -> April Tag. Three April Tags will show up in the viewport.

  • Open up the Stage Tree, and then open the ActionGraph by right-clicking on the prim and selecting Open Graph. The ROS Clock publisher, TF publisher and Camera Helper nodes (for initiating the camera_info and rgb image publishers) should already be setup.

  • Press Play to start publishing data to ROS

../_images/isaac_ros_apriltag.png

  • In a new terminal with your ROS environment sourced, run roslaunch isaac_tutorials apriltag_continuous_detection.launch to run the april_tag detection node.

  • In a new terminal with your ROS environment sourced, run rviz -d <noetic_ws>/src/isaac_tutorials/rviz/apriltag_config.rviz to start rviz and show the detections from the camera image

  • To see the raw data for the detected tags run rostopic echo tag_detections

../_images/isaac_ros_apriltag_rviz.png

7.1.14.4. Summary

This tutorial shows the basics of detecting April Tags in Omniverse Isaac Sim.

7.1.14.4.1. Further Learning