ROS 2 Publish Real Time Factor (RTF) — Isaac Sim Documentation

Last updated: 12/12/2025

Title: ROS 2 Publish Real Time Factor (RTF)#

URL Source: https://docs.isaacsim.omniverse.nvidia.com/latest/ros2_tutorials/tutorial_ros2_rtf.html

Published Time: Tue, 21 Oct 2025 19:25:26 GMT

Markdown Content: Learning Objectives#

This tutorial will demonstrate publishing the Real Time Factor (RTF) of Isaac Sim as a ROS2 Float 32 message.

Getting Started#

  • Enable the isaacsim.ros2.bridge Extension in the Extension Manager window by navigating to Window>Extensions.

Publish RTF#

The RTF indicates how fast or slow simulation is running with respect to the real-time. It is calculated per frame as RTF = simulated_elapsed_time / real_elapsed_time. If RTF is greater than one,the simulation time is running faster than wall clock time. If RTF is less than one, the simulation is running slower than real-time.

  1. Go to Tools > Robotics > ROS 2 OmniGraphs > Generic Publisher. The parameter pop-up window will appear.

  2. Select Publish RTF as Float32 and click OK.

Image 1: ROS2 RTF Parameter

  1. A new Action Graph will be created with the Isaac Real Time Factor node connected to a generic ROS2 Publisher node, which is setup to publish std_msgs/msg/Float32 ROS messages.

  2. Select the Action Graph prim found at /Graph/ROS_GenericPub. Right click on it and choose Open Graph. The autogenerated graph should be match the following:

Image 2: ROS2 RTF Graph

  1. Click Play to start simulation.

  2. In a ROS2-sourced terminal run the following command to view the RTF value published from Isaac Sim.

ros2 topic echo /topic For an unloaded system, RTF should be close to 1.0.

Summary#

This tutorial covered using an OmniGraph shortcut to automatically generate a ROS2 RTF publisher graph.

Next Steps#

  • Continue on to the next tutorial in our ROS2 Tutorials series, ROS 2 Cameras, to learn how to add cameras and receive ground truth synthetic perception data through ROS 2 topics.

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