Laggy Gazebo simulation and low real time factor

This is a continuation of my previous post. I am still experiencing very laggy gazebo sim as shown in this gif. I don’t have any VPN or firewall running.

Computer specs: Ryzen 5 7600, RTX 2060 super, 32 GB ram (CPU and memory utilization < 20%)
Internet speeds: 500mbps up/down

When I try to move the robot in Gazebo, it always lags like you see here. It does the same on my laptop (which also has no firewall or VPN running, and low CPU and GPU utilization).

Any ideas?

Hi Spencer,

I’m sorry you are still having this issue, especially that there’s no reason for it as far as I can see. All the specs are A-star!

To troubleshoot further:

  • Are you having a similar experience when you launch courses? It seems that something is “rate-limiting” the speed at which you connect the simulation - perhaps an antivirus or Internet Security suite.
  • Could you try another PC and network altogether to see if the same thing happens?

Hi @bayodesegun, thanks for the reply.
I have good news. When I launch a simulation in a course, it seems to run totally fine, smoothly, responsive, etc. So the problem appears to only be with rosjects (specifically, I launch the wall following Gazebo environment with roslaunch realrobotlab main.launch).

Nothing has changed on my computer or internet connection between trying the rosject and the course. Any idea what could be causing the lag in the rosjects?

Also, I did try a different and quite well spec’d computer on my same network, and it has the same lag in the rosject.


Hi Spencer,

Thanks for sharing the good news. It’s a definite step forward, and we can troubleshoot further.

There are key differences between simulations in the course and ROSDS environments:

  • ROSDS uses gzclient while the courses use gzweb, mostly. gzweb is generally faster.
  • We connect to the gzclient running on the vm via a remote desktop connection, vs a direct browser connection used by gzweb.

So, I would focus on the connection aspect of your network. Not necessarily the speed but any blockages or rate-limiting, considering remote desktop connection specifically.

Are you able to try a different network?

Hi again @bayodesegun
I opened ROSDS on my laptop, using my phone’s 4G connection instead. Speedtest shows the connection speed at 40mbps down/40 up.
In the same ROSDS project, the simulation is laggy as before.
Is it possible this is related specifically to this one rosject I am trying to run? I haven’t made any other rosjects yet, but should I possibly try to run a new rosject, or do you think I would encounter the same issues.


Thank you for the update. For sure, we’ll get to the bottom if it!

Trying another rosject is a very good idea. Please go ahead. I will also do further tests here.

I think the key here is the real time factor you are getting. I just tried and got 6.9+, and the simulation did not lag. Not sure what might be responsible here, perhaps you are too far away from your VM :frowning:

Please try another rosject as you said and let’s compare.