Smooth Sync: Sync your Transforms Smoothly across the network

[fuestrine]

Megurine
Hi. I'm not seeing this issue with a blank ThirdPersonExample template. I have two SmoothSyncs with one hooked up to the CameraComponent and then I disable the SmoothSync hooked up to the CameraComponent on BeginPlay. I can't get it to crash on quit or windows key. Your crash log doesn't seem to help me either unfortunately.

Does this happen in a blank ThirdPersonExample template for you?
If not, can you give me any other details that may help me to recreate the issue?

[Megurine]

Hi, I'm sorry I can not redo it, I think it was a mistake for exiting/switch window, but I think it was the bug below.
The second smoothSync is not important (the bug works with only one).

The bug spawn when I set SyncAngularVelocity to None.

The crash from a new blank project :
https://streamable.com/w3lb3

As you see my pawn dont use an UE generic component for movement, its maybe the cause ? (because the bug dont appear on the ThirdPersonExample)

[Megurine]

Another crash (can be reproduce in ThirdPersonExample), easy to fix in game and directly on the plugin :
UE crash if you use SmoothSync.teleport if your smoothSync is enabled false.

[e3pojedi]

fuestrine I'm thinking about buying this plugin, but I have a few questions:

1:How many players can it support at once?
2: Does it support replay?
3: If latency of 200ms and 20% packet loss is introduced, what would happen? (Video/gif would be great!)

[fuestrine]

Megurine
Sorry about the issues and thanks a ton for bringing them to my attention. Thanks also for that great video, it allowed me to recreate the issue perfectly.

It'll probably show up on the Marketplace in a day or two but I also sent you the fix in a PM in case you want it sooner. It'll fix both your issues.

[fuestrine]

e3pojedi
1. No clue really, I don't see why there would be a limit on players unless you are completely overloading the networking that Unreal's networking allows. SmoothSync provides you with the ability to lower the send rate to really low and still be smooth so I'd imagine a decent amount of players could be had.
Here's Smooth Sync multiple object syncing in comparison to Unreal's Replicate Movement at low send rate with same priority for both: https://www.youtube.com/watch?v=RYo2...=youtu.be&t=31

2. If you mean like playback of old States(position, rotation, etc.), it does not. There is a list of old States that are kept in the stateBuffer[] though that you have access to.

3. Depends on your settings and what your ping and SendRate was before. The most important part is that you set your InterpolationBackTime to be a set amount of time in the past. If you ever don't receive a State update for the amount of InterpolationBackTime, it will start extrapolating (extrapolation can also be turned off and the object will just not move if receiving no new States).
After it receives a new State again, it will move towards the new State's position and rotation.
I've got no video, but if you have an easy way to simulate packet loss percentage and changes in ping, I'll see if I can make one.

[fuestrine]

e3pojedi
Oh yeah, some more info:
3. Smooth Sync will adjust to new ping rates as well. So if you start out at 100ms then go to 200ms in the middle of the game and stay at 200ms, it'll adjust depending on the TimeCorrectionSpeed variable, which you can set. Then you'll only have to worry about the packet loss making it go beyond your InterpolationBackTime.

Let me know if you want further explanations on anything.

[e3pojedi]

@fuestrine Thanks for the info! You should be able to test lag using the console by typing "Net PktLag=200" (test latency in ms) and "Net PktLoss=20" (test % of lost packets) - https://www.unrealengine.com/en-US/b...based-exploits
Also, are there Anti-Cheat Systems for this plugin?

[fuestrine]

e3pojedi
Awesome, I didn't know Unreal was able to do that so easily. Thanks for teaching me about it.
Video of packet loss and packet lag: https://www.dropbox.com/s/p7441m51m0...17-51.mp4?dl=0
This is using the default SmoothSync settings.
You can see the output when I press the button to start simulation.

There are no anti-cheat systems built in but you can do your own checks on the RPC server_validate methods and see if they are moving too fast or anything.

[e3pojedi]

You, sir, are truly a life-saver!! Just purchased it and it works!! I am so happy right now, my car-based game was super laggy and unplayable and now it's as smooth as butter. I can't thank you enough!
@fuestrine

[fuestrine]

e3pojedi
Good to hear! If you like my product, every 5 star review helps it get noticed a bit more.

Let me know if you have any suggestions or anything. Cheers.

[e3pojedi]

Quick Question - If any more than 2 players join then they are not showing up - How do I fix this? @fuestrine

[fuestrine]

e3pojedi
What do you mean "they are not showing up"? The actors don't exist? They exist but movement isn't being synced?
I'm not seeing this issue in templates like ThirdPerson. Some of the templates aren't made to be controlled in multiplayer though so you may have ownership and control issues depending on the template. Let me know which template you are using, if you are using one, and I can know more of what's going on.

[e3pojedi]

@fuestrine I figured out what it was - The player would not be "synced" with the other clients unless he had stopped moving fully. The instant that happens then the player appears, but the position and rotation is not tracked - I'm using a modified version of the kart template here (Without PhysX) - https://ue4resources.com/3d-projects - https://drive.google.com/open?id=1Ew...OaiYLnvI--98KG

[fuestrine]

e3pojedi
Hmm, that's a weird one. Make sure Unreal's Replicate Movement is unchecked and that Unreal's Component Replicates is unchecked. Replicates should be checked on the Actor though.

If it's not that, I'll get some time to check out that kart template tomorrow. It should be easy to track down with an example like that. I'll message you then.