Unity Netcode Lag Compensation using Extrapolation

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Күн бұрын

Develop procedural Extrapolation that goes beyond the basic implementation provided with Netcode for GameObjects. This video is Part 2/2 about handling prediction, reconciliation, and other techniques related to lag and cheating in multiplayer games!
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▬ Contents of this video ▬▬▬▬▬▬▬▬▬▬
0:00 Intro
1:19 Client-Server Reconciliation
4:22 Latency and Extrapolation
16:00 Testing
18:20 Free Tools
20:00 Outro
Source code: github.com/adammyhre/Unity-Mu...
KART Models used in this video
opengameart.org/content/modul...
Open Source Projects
github.com/VeriorPies/ParrelS...
github.com/mminer/consolation...
github.com/Huntrox/CommandCon...
Asset Store (Affiliate Links)
assetstore.unity.com/packages...
SYNTY Racing Kit: assetstore.unity.com/packages...
Cartoon Remaster VFX (FREE): assetstore.unity.com/packages...
Casual Game SFX (FREE): assetstore.unity.com/packages...
DOTween (FREE): assetstore.unity.com/packages...
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Пікірлер: 28

@git-amend 10 ай бұрын

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!

@jack-zc3gj 10 ай бұрын

these are great! thank you!

@git-amend 10 ай бұрын

Thank you!

@tarriochu95 9 ай бұрын

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

@git-amend 9 ай бұрын

Great to hear!

@barbra09 6 ай бұрын

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

@desine_ 8 ай бұрын

damn, you are good, nice content

@git-amend 8 ай бұрын

Thank you 😀

@josuealgarzia 5 ай бұрын

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?

@mrtnt1666 10 ай бұрын

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

@git-amend 10 ай бұрын

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 10 ай бұрын

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 10 ай бұрын

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

@git-amend 10 ай бұрын

@@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_ 8 ай бұрын

thank you

@seansmith5022 5 ай бұрын

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 5 ай бұрын

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.

@bryanavila4300 10 ай бұрын

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

@git-amend 10 ай бұрын

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.

@desine_ 8 ай бұрын

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_ 8 ай бұрын

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 8 ай бұрын

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.

@desine_ 8 ай бұрын

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

@git-amend 8 ай бұрын

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

@DavidVerified 8 ай бұрын

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_ 8 ай бұрын

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

@git-amend 8 ай бұрын

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.