How to adjust simulation speed in Isaac Sim?

[rwalia]

Isaac Sim Version

5.1.0

Operating System

Ubuntu 24.04

GPU Information

• Model: RTX 5080
• Driver Version: 580.95.05

Topic Description

I want to control the simulation speed in Isaac Sim, similar to how Gazebo allows adjusting the real_time_factor (Simulation Speed in Gazebo). What is the best way to do this?

What I’ve Tried

1. Launched Isaac Sim with my script in this style: APP_SCRIPT.(sh|bat) --enable isaacsim.core.api (as suggested here: [isaacsim.core.api] Isaac Sim Core — Isaac Sim)

2. Tried setting world.set_physics_step_size(step_size) as mentioned here: Isaac Sim Performance Optimization Handbook — Isaac Sim Documentation

from isaacsim.core.api import World # from https://docs.isaacsim.omniverse.nvidia.com/5.1.0/py/source/extensions/isaacsim.core.api/docs/index.html#world

# Get or create the current World instance
world = World()

# --- Get current physics step size ---
current_step = world.get_physics_step_size() # Not sure if this API exists
print(f"Current physics step size: {current_step} seconds")

# --- Set a new physics step size (e.g., 1/120 = 120 Hz) ---
new_step = 1.0 / 120.0
world.set_physics_step_size(new_step)
print(f"New physics step size set to: {new_step} seconds")

I got the following errors:

Related Issues

One thing to note, is that my simulation doesn’t have a “PhysicsScene” associated with it. For example, this screenshot was included in the “speedup cheat sheet” (Isaac Sim Speedup Cheat Sheet — Isaac Sim Documentation):

This is what mine looks like:

Nonetheless my simulation is running fine (my robot responds to cmd_vel).

Additional Context

Note that my primary goal is to control sim speed. If there is a better and more direct way, please share!

[VickNV]

Please check if the information in the topic World time and simulation time is helpful for adjusting simulation speed in Isaac Sim.

Also, an internal ticket has been created to track and resolve the out-of-date documentation issue.

[rwalia]

Hi @VickNV , thanks for sharing that link. It does answer my question: I can adjust the sim speed via a script-run simulation. However, it would be nice to have a setting that I can adjust via GUI, since my experiment does not run from a script. Is there a way I can create a feature request ticket for that?

I’ll mark accept your answer to mark this issue resolved. Thanks!