Unity Netcode Lag Compensation using Extrapolation

[@git-amend]

Hey everyone, hope you find this topic interesting! I'm excited to share a few new things I learned, and I found a few new FREE tools to help with building Multiplayer games too! Check 'em out!

[@tarriochu95]

this is extremely helpfull and insane. I will recomend this to my peers

[@git-amend]

Great to hear!

[@seansmith5022]

Hey I know it's a shot in the dark but I have a problem when running on the client and pressing q to teleport, it teleports back and forth a random amount of times as the client's lastserverstate is getting set to 20 on the Z when it shouldn't be. This doesn't happen when the clientnetworktransform's authority is set to server but when it's set to server, there's no instant movement. So the point in the video at 4:00 never works for me unless I'm the host and I'm certain the code is the same, I've gone through it so many times. Any help would be greatly greatly appreciated!!

[@josuealgarzia]

hi! I solved this problem by getting rid of both Client Network Transform and Network Tranform atached to the player prefab and using a ServerRpc to coordinate updating the location of a given client to all other clients: [ClientRpc] void SendToClientRpc(StatePayload statePayload) { if (IsOwner) { lastServerState = statePayload; } else { moveThisPlayer(statePayload); } } I don't know if it's a correct solution but it worked for me.

[@jack-zc3gj]

these are great! thank you!

[@git-amend]

Thank you!

[@castlecodersltd]

Another great, helpful video. Thanks 🙂

[@git-amend]

My pleasure!

[@joshdev09]

i have this implemented in my state machine movement controller, and im having a issue, i have a boat with a rigidbody and when the boat moves i want the player to move with it, but the server thinks the movement is wrong and stops the player from moving, so if the object is parented i need it to include the parents velocity and position how would incorperate this

[@mrtnt1666]

is there a using parameter for "CountdownTimer" or something? sorry having some trouble

[@git-amend]

There is a Timer class in the Utils folder of the repository (and some other useful classes) github.com/adammyhre/Unity-Multiplayer-Kart/blob/master/Assets/_Project/Scripts/Utils/Timer.cs

[@git-amend]

There is a Timer class in the Utils folder of the repository (and some other useful classes) github.com/adammyhre/Unity-Multiplayer-Kart/blob/master/Assets/_Project/Scripts/Utils/Timer.cs

[@mrtnt1666]

@@git-amend Thanks! I'm having the same problem with "AuthorityMode and "ClientNetworkTransform" did I miss something else or no?

[@git-amend]

@@mrtnt1666 I believe that was created in the episode before this one. At any rate, all files are in the repository. Look in the /Scripts folder.

[@desine_]

thank you

[@josuealgarzia]

thank you so much for your videos, they are short but packed with information, which is why I have already watched them several times. what I can't understand is why the reconciliation happens so often, at least in my game, since I'm doing a fps conpetitive game I can't set the threshold above 0.1f. I know it is a low threshold but in theory the discrepancy between the server and the client must be almost zero without lag or cheating. However, I notice that the discrepancy between the client's position according to the server and that of the client widens very quickly causing a reconciliation almost every frame. I also investigated to make sure the motion and gravity calculations were 100 percent deterministic and that it wasn't a problem given the limitations of floating points but still the problem persists. do you have any advice?

[@desine_]

I have a problem. My client's authority flickers on the server. Because of this, when server goes through ProcessMovement for Reconciliation check it tries to add velocity - which is not possible for kinematic rigidbodies Do you have any idea why this is happening?

[@desine_]

private void Extrapolate() { if (IsServer && extrapolationTimer.IsRunning) { //transform.position += extrapolationState.position.With(y: 0); body.velocity = extrapolationState.velocity.With(y: 0); } } I know I'm wrong about signing velocity, but if I do this "transform.position += extrapolationState.position.With(y: 0);" the client flies away at insane speed

[@git-amend]

Sorry, but I don't really have enough information to debug that issue for you. Debugging Netcode issues is challenging. It could be any number of things, but I would suggest looking first at the method calling Extrapolate, and also the conditions for ending the extrapolationTimer.

[@donavilon]

Hello I'm having some wierd issue that the te extrapolation does not stop, and the server keeps going away

[@git-amend]

I'll need more information to be able to give any advice. Make sure to compare your code against the code in the repository. You should be able to spot any discrepancies there.

[@muriilouwu]

did u find a solution? my problem is the same, even after the method extrapolate is called, the game continues to extrapolate the position and never give back the player's power to change its direction

[@DavidVerified]

Oh maaan I'm just too stupid to understand this... I mean you showed at 6:54 that the server and laggy clients position are almost identical on server side. Only for the laggy client everything else is lagging behind. So why shoud you need Extrapolation to simulate movement on serverside? They are almost identical. So Extrapolation is supposed to benefit the lagger? EDIT: Oh wait!! Is it actually supposed to benefit everyone else by even removing the smallest discrepancy between server position and laggy-player position on serverside?

[@desine_]

you are not stupid, you just need some mode time and you will get there

[@git-amend]

You are correct - extrapolation is for the benefit of the other players, with the hope that the lagging player will recover and resume playing as normal.

[@desine_]

It's ok at this point that client interpolates constantly, right?

[@git-amend]

Yes, you can use both interpolation and extrapolation at the same time.

[@desine_]

damn, you are good, nice content

[@git-amend]

Thank you 😀