I’m working on getting vehicles into my already working Multiplayer. However I struggle to get the working correctly. I’m assuming that Vehicle Movement Component replicates movement the same way as the Character Movement Component.
When I drive a vehicle in Multiplayer, on all Clients it’s very stuttery. It’s more like a teleporting to the next (server) location and no smooth movement. I can disable Replicate Physics to Autonomous Proxy and the stuttering is gone. This however has the result that vehicles desync very fast.
I also have a Truck and Trailer System, attach a trailer to a vehicle amplifies the stuttering issues even more.
How do I get a smooth vehicle movement in Multiplayer? I double checked, there is nothing interfering with the movement and it’s a straight passtrough from input to the movement component.
I did already enable Physic Substepping and tried to tweak values on this front but no luck.
I think you need some sort of client side movement prediction.
As far as I know, the Chaos Vehicle Movement Component does NOT predict client side movement. On the other hand, the Character Movement Compomemt does the prediction, leading to a smooth movement on clients.
I use the plugin “Smooth Sync” for client side prediction on my vehicles. I can not give you detailed results, because I did not yet fully investigate this plugin. But: My first tests showed less stutter while driving on the client.
Yes, the issue is well known in this community. We need Epic to take action or create a tutorial that explains how to work around the problem. I’m trying to link all the related posts since this question is a recurring issue that needs to be addressed every week.
We created a bug report for this with 144 upvotes, and it was fixed in version 5.2. However, the jittering issue on clients still persists. So, I’m considering giving up to some extent. Perhaps there’s someone willing to create a tutorial with source code to address this issue, as it seems the engine team won’t allocate resources to fix it.
Here are posts from other people on the same issue:
The worst part is, as of UE 5.3, the Smooth Sync Plugin is broken and it does not sync anything correctly. Meaning Vehicle Multiplayer is more or less impossible withe UE 5.3
You might could try increasing the net update frequency, along with setting Component Should Update Physics Volume to true on the vehicle movement component. Depending on your multiplayer setup you might need to also Enable Physics On Dedicated Server on the skeletal mesh component as well. You could also tool around with Physics Transform Update Mode and try setting it to Simulation Updates Transform Component. Net load on client also…
The multiplayer vehicles are almost entirely simulating physics over the network so it’s very difficult, but it can be done for sure and smoothly at least as far as 5.1. Beyond that you might be facing a replication issue. I could say that’s a very likely issue if you’re just passing input axis values directly to add input?
