ROS2 Policy Mismatch

[pekachoo]

Hey there!

I trained a policy on IsaacLab and made a ROS2 node that runs the policy in my Isaacsim ROS2 environment. The issue is, it seems like the behaviour is off.

I made sure nodes are published on physics step, and are also matching frequencies in both IsaacLab and Isaacsim (60Hz). I also use the exact same USDs in both. I use joint_velocity as the action in rad/s, and I bring this up because I noticed if I set joint velocities to be the same in both sims, their speeds look different (the second video). I thought it's just because of a frame_rate difference but I thought I'd mention it in case its relevant.

Screencast.from.2025-12-29.11-52-20.webm

Screencast.from.2025-12-24.11-18-35.webm

[RandomOakForest]

The most likely root cause is a unit and controller mismatch between Isaac Lab (rad/s) and Isaac Sim (often deg/s at the drive level) plus potential differences in how the ROS2 controller applies those commands. This seems to be a post better fit for the Isaac Sim repository.

[pekachoo]

I think in the end it was just a perceived frequency issue since the sim2sim deployment still worked properly. For example, Isaacsim might update a little slower than Isaaclab, so it appears to be rotating "slower" but it's actually just updating slower. It also could've been a robotcfg mismatch since IsaacLab overrides whatever the USD is set to.

Everything seems to be fine from my end now since this problem was encountered a couple months ago but thank you for the insight!