Rollback netcode research

[ndeke]

I've been doing research on fighting games netcode. I just wanted to ask wat is all of your opinion of fighting games netcode(sf6, T8 and mk1) vs other genres like fps. Why is there such a big gap in performance and quality.

[Bnuuy]

https://www.youtube.com/shorts/bdvAlB1Ngpc Here's a youtube short that explains how rollback works exactly. From what I understand, Rollback is more stable because it works with predictions that can be easily corrected, while delay-based spits it out 1:1 which is abysmal with high ping.

[Kiyaya]

Well correct me if I am wrong but most all FPS games run on dedicated servers where all players are connecting to one server that hosts the game state and the players receive updates about the game state from the server.
Fighting games on the other hand are entirely peer to peer- no intermediary server involved.
Netcode functions differently at a fundamental level because of this key difference.

[Red]

Originally posted by Kiyaya:

Well correct me if I am wrong but most all FPS games run on dedicated servers where all players are connecting to one server that hosts the game state and the players receive updates about the game state from the server.
Fighting games on the other hand are entirely peer to peer- no intermediary server involved.
Netcode functions differently at a fundamental level because of this key difference.

Pretty much this. And FPS are 3D, so there tends to be interpolation and stuff to try and predict where players will be, some leniency is allowed but it's ultimately the server that decides whether something actually happened or not.

In fighting games, the closest concept to that is game states for rollback. By default, whenever there's a desync/missing input, rollback netcodes assume the opponent is doing the same action as on the previous frame. Then, if it turns out the late inputs are different, the game will fix what's on-screen accordingly.

[ndeke]

Thanks guys. I'm trying to learn as much as possible. This is really helpful.

[omni]

Originally posted by Kiyaya:

Well correct me if I am wrong but most all FPS games run on dedicated servers where all players are connecting to one server that hosts the game state and the players receive updates about the game state from the server.
Fighting games on the other hand are entirely peer to peer- no intermediary server involved.
Netcode functions differently at a fundamental level because of this key difference.

pretty sure cod and tarkov are peertopeer (1 player hosts everyone else connects to them)

[Kiyaya]

Originally posted by omni:

Originally posted by Kiyaya:

Well correct me if I am wrong but most all FPS games run on dedicated servers where all players are connecting to one server that hosts the game state and the players receive updates about the game state from the server.
Fighting games on the other hand are entirely peer to peer- no intermediary server involved.
Netcode functions differently at a fundamental level because of this key difference.

pretty sure cod and tarkov are peertopeer (1 player hosts everyone else connects to them)

Yes, looking it up I can say that is correct.
SPECULATUON WARNING
However, if I had to hazard a guess as to how it works, the "host" is the primary game state that sends updates to the players connected to the host. In fighting games, it's a mutual connection where both peers have their own game state and are updating each other (thus being susceptible to stuff like desyncs).
In this way, the way the netcode functions is still fundamentally different even if the type of connection is the same.
However, as stated, this is all speculation and me talking out of my ass because my 15 minute break isn't long enough to actually go research this ♥♥♥♥ so maybe I'm just a dummy spouting misinfo on the internet.