Client Players Jitter on Listen Server Host

Running UE4 12.5-3039270, build date Jul 6 2016

I’m having what appears to be the same issue as the two questions below:
https://answers.unrealengine.com/questions/358869/clients-jitter-on-listen-server.html
https://answers.unrealengine.com/questions/434642/listen-server-charactermovement-has-no-interpolati.html

In the first linked thread above, I was asked to make a new question for my problem.

Basically, client players appear to jitter around (as if there’s no interpolation being applied to their position) on the listen server host’s screen, but not the other way around. Clients see players with proper interpolation applied on their screens. This is causing a pretty big problem for me, hoping someone can point me in the right direction.

According to the first thread above, the issue had been reported as fixed. This could definitely be a different but similar issue. Is anyone else still having this problem with networked games? I recorded a short video trying to show the problem, and have included a link to it below.

The server is on the right, and the client on the left. If you watch closely, you notice that the player moving around is much smoother on the left player's (client's) screen.

I’m thankful for any help you can provide!

Hey gooberCP,

I am unable to reproduce the issue you are having and it doesn’t look like the original reports. As an example:

https://www.youtube.com/watch?v=Bq19tO2EXVQ

With that said, there is a report where if you have a SpringArmComponent that has bEnableCameraLag, it can cause the SkeletalMesh it is attached to to jitter around.

You can see that here:

https://issues.unrealengine.com/issue/UE-34580

Since your game is using the First Person arms, I do not think this is the same thing you are experiencing.

In order for us to help troubleshoot the issue we will require additional information from you.

  • What is being replicated in your project? If you are sending a lot of data through the network, that could definetly cause a hiccup now and a again.
  • Are you replicating any movement twice? By default, the Character class will handle movement replication. If you replicate movement again in your class, this can cause a issue.

Hey I’m having a similar problem, I’m testing my multiplayer game with my laptop and pc ( with pc hosting the server via steam) on the client side things seem to work fine, but on the serverside there is some jittering on the client movement. I also get these lag spikes where my client actor starts running in one direction and will eventually teleport further in that direction ( as the lagspike ends). I’m assuming there is something wrong with my implementation.

here is a link to a post i made, containing some of the details of my implementation.

Thank you in advance for any ideas how to resolve this issue =)

-Samuelb

[From the forum thread]

Update

I’ve managed to fix the problem where the other actor on clientside would “follow” under the level. I changed both actorblueprints to execute on server with a custom event (run on server and reliable) and on event tick calling the custom event. However, even though this solves the problem, i’m experiencing some lag now when testing. The game works fine when only one character is moving, but when i move both characters at the same time the client character will start warping around. I think i’m overloading my bandwidth with information, but i’m not exactly sure. Has anyone else had this issue?

Update2

I think I’ve managed to fix the problem, earlier I had checked “Always relevant” for the actorlookat actors. By unchecking this option, the lag spikes seem to be a lot less frequent or don’t happen at all.

-Samuelb