Client replication vehicle movement lag

We create a multiplayer car сombat game. When the vehicle move on the client and in vehicle SpringArm set EnableCameraLag = true - it is lagging. It does not depend on ping.

Hey Gelani,

Most likely the Client character or vehicle is causing a large enough network load between Server and Client. This is probably from an overdependence on Reliable RPCs or simply too many network calls. You can get a good look at what is specifically causing the network lag by using the Network Profiler. Once you’ve identified the actor or actors that are causing the lag, you can start eliminating extraneous network calls.

But 4.8 all be fine. And is lag then is server and client in some machine. Are you tested the multiplayer with vehicle? 4.9 some error.

I have tested with the Vehicle Advanced template project in 4.9 and 4.10, both in editor and packaged project. Again, I would recommend using the Network Profiler to identify the source(s) of the lag you’re experiencing.

Test Vehicle template in 4.9, and in spring arm set checked “Enable camera lag”. And you will see lagging.

Okay, I tried that and still don’t see any lag on the Client.

  1. Are you using a vanilla version of the engine, or have you edited source code at all?
  2. Is this a BP only project, or have you added code?
  3. Is this occurring while playing in the editor (PIE), or only in a packaged game? If in the editor, which play mode are you using?
  4. Have you used Network Profiler yet?
  1. 4.9.2 Realese
  2. Create BP project Vehicle
  3. in Sedan blueprint SpringArm set EnableCameraLag = true
  4. Package game (Widows 64)
  5. Lanch listen server
  6. Lanch client (in some machine)
  7. On client vehicle is lagging when speed is high ( 100 km/h )

Thanks for the extra details, but I still don’t see any lag on the Client. You’re not referring to the shifting gears, are you? Can you post a video somewhere?

Have you used Network Profiler in the editor yet?

Yes I use Network Profiler.

That video appears sped up. Can you send one at normal speed? Or are you speeding it up in the editor?

What results did you get from Network Profiler? Can you post a screenshot, please?

Video is normal speed. I capture this through NVidia Shadow Play. It is package game. Network Profiler will show the same as you. It’s a standard project “Vehicle”.
You really do not notice how the car jerks?
OK. I later send screenshots.

The only jerking motion I see is when the car is mid-gear, while shifting. But the video is super fast, so I don’t know if I’m missing something.

Have you adjusted the framerate in your project?

I am trying to help you. If you don’t give me something to work with and I ask for clarification, or other information, please don’t throw useless memes at me.

The video you posted is playing super fast and I cannot clearly see any lagging in 5th gear. If you can post a video that’s not sped up like that, I might be able to see it.

As it stands, simply creating a Vehicle template project, packaging, and playing on the Client, I do not see any lag on the vehicle’s movement at any point in the vehicle’s gear cycle. If you want to post your test project somewhere and send me a link, I can check there as well. Otherwise, I have to assume this is a problem on your end.

It is not video frame rate, it is vehicle jerking in 5 gear in end video.

OK. I made 2 projects (4.8 & 4.9) and share link to those. For us it is a critical error, we make car the combat game, but because of this error, we will forced to either postpone the release. 4.8 everything worked well when we switched to 4.9 - there was this error.

If you can get me a link to the 4.8 project and/or the 4.9 project, I can take a look.

4.10 Release (Not source)

Thanks! I had to create some networking functionality in the project to properly test in a packaged project, but once I did I also noticed a bit of lagging on the Client. When I attempted to record it, it got much worse. I’m not certain what’s causing it, nor why I didn’t see the same in a new project I created earlier in 4.9.

I also tested your project in our internal build (which will eventually be 4.11), and the lagging did not occur. It’s possible you’re seeing this more on your end than I am on mine, however, so if you’d like to test to see if this is resolved in an upcoming release, your best bet is to grab the latest Promoted build on GitHub and create a copy of your test project in that. Let me know if you still see lag in there and we can investigate further.

I will try 4.11 and report results