Client replication vehicle movement lag

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

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Hey Gelani,

Most likely 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 network lag by using the Network Profiler. Once you’ve identified actor or actors that are causing 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 multiplayer with vehicle? 4.9 some error.

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

  1. Are you using a vanilla version of 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 editor (PIE), or only in a packaged game? If in 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 extra details, but I still don’t see any lag on Client. You’re not referring to shifting gears, are you? Can you post a video somewhere?

Have you used Network Profiler in 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 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 same as you. It’s a standard project “Vehicle”.
You really do not notice how car jerks?
OK. I later send screenshots.

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

Have you adjusted 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.

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 Client, I do not see any lag on vehicle’s movement at any point in 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 combat game, but because of this error, we will forced to either postpone release. 4.8 everything worked well when we switched to 4.9 - there was this error.

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

4.10 Release (Not source)

Thanks! I had to create some networking functionality in project to properly test in a packaged project, but once I did I also noticed a bit of lagging on 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 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 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 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