Does anyone know how Fall Guy's net code was implemented? It's very smooth with 100 participants.
How fighting games use delay-based and rollback netcode (2019)
21–30 of 107 posts
Re: How fighting games use delay-based and rollback netcode (2019)
#22Earlier quoted context omitted.
> I wonder if any fighting games have thought to train a neural network per player to try and predict the player's actions N frames ahead. The entire point of playing a fighting game is to attempt to solve this problem. A good player, by necessity, can't be accurately predicted; if they could, they'd be a bad player.
A good player can't be accurately predicted by a human
First, a good player can't be accurately predicted at all; the conclusion from game theory is direct and clear. This is a case where a strategy involving picking moves at random is superior to any deterministic strategy.
Second, your rebuttal is not especially good support for the idea that we should be trying to solve the problem with a technology specifically designed to imitate humans.
Re: How fighting games use delay-based and rollback netcode (2019)
#23Super smash bros melee is having a bit of an online renaissance due to a combination of the COVID 19 pandemic and the recent implementation of rollback netcode by a community member that quit his job.
The rollback is truly something else. Although - and I may be crazy - I swear it isn't quite as good as playing local people with delay-based netplay (such that the network delay can "hide" behind the inherent lag of the Gamecube/game itself) But outside of that edge case, it's outstanding.
The fact that they were able to optimize two frames of input lag away to make the online gameplay have the same latency as offline is itself incredible.
As far as I know, even other rollback-equipped fighting games still add a little bit of latency in order to play online without requiring constant rollbacks.
That said, Melee is also a game that is very hard on the rollback, because movement and attack startup are far faster than in many fighting games.
Dashdancing with rollback leads to some annoying camera judder.
Re: How fighting games use delay-based and rollback netcode (2019)
#24Super smash bros melee is having a bit of an online renaissance due to a combination of the COVID 19 pandemic and the recent implementation of rollback netcode by a community member that quit his job.
The fact that Fizzi was able to get implement rollback netcode for a game by just directly editing the assembly code without any access to a the game's source code is insane. The delay based netcode for the newest smash game, Smash Ultimate(2018), is so bad that it went from being the biggest fighting game of all time in terms competitive playerbase to basically having no scene at all due to covid killing lan tournaments. No one wants to play ultimate online. I wonder if this comparison is what caused nintendo to cease and desisted an online melee tournament that intended to use rollback.
Re: How fighting games use delay-based and rollback netcode (2019)
#25Does anyone know how Fall Guy's net code was implemented? It's very smooth with 100 participants.
Based on Fall Guy's hiring page, which asked for experience with Photon, it's probably this: https://www.photonengine.com/en/pun
Re: How fighting games use delay-based and rollback netcode (2019)
#26Does anyone know how Fall Guy's net code was implemented? It's very smooth with 100 participants.
I don't know anything about their net code, but I suspect this is more about the fact that the game is less dependent on precise timing then something like a shooter or Smash.
Re: How fighting games use delay-based and rollback netcode (2019)
#27Earlier quoted context omitted.
The rollback is truly something else. Although - and I may be crazy - I swear it isn't quite as good as playing local people with delay-based netplay (such that the network delay can "hide" behind the inherent lag of the Gamecube/game itself) But outside of that edge case, it's outstanding.
The fact that they were able to optimize two frames of input lag away to make the online gameplay have the same latency as offline is itself incredible. As far as I know, even other rollback-equipped fighting games still add a little bit of latency in order to play online without requiring constant rollbacks. That said, Melee is also a game that is very hard on the rollback, because movement and attack startup are fa…
AFAIK they didn't do anything special to save two frames, just a CRT (which is what's used on LAN) has 2 frames of lag.
Re: How fighting games use delay-based and rollback netcode (2019)
#28Prediction code for rollback is somewhat akin to branch prediction code in that the dumbest solution works surprisingly well but there's incremental efficiency gains to be had. I wonder if any fighting games have thought to train a neural network per player to try and predict the player's actions N frames ahead. The neural nets could be used for smoother netcode but if the accuracy got high enough, they could, eg: al…
Well over ten years ago I read a research report that claimed many dozens of players in Quake III using a variety of techniques including replacing linear dead reckoning with a traditional AI for each player.
Re: How fighting games use delay-based and rollback netcode (2019)
#29This piece was really interesting. That you can hide network delays by building a “fake” model of the other player that replicates what a real player would do and rolling back when this prediction fails.
So you can train some neural nets on what players do in such situations and you get a certain accuracy.
And yet you can keep making this “fake” player better and better until it’s indistinguishable from fighting a human and we arrive a nice little paradox.
These kinds of games and algorithms are really good proving grounds for AI. And I begin to get why the author is so passionate about this stuff and it’s possibilities.
Re: How fighting games use delay-based and rollback netcode (2019)
#30Super smash bros melee is having a bit of an online renaissance due to a combination of the COVID 19 pandemic and the recent implementation of rollback netcode by a community member that quit his job.
The fact that Fizzi was able to get implement rollback netcode for a game by just directly editing the assembly code without any access to a the game's source code is insane. The delay based netcode for the newest smash game, Smash Ultimate(2018), is so bad that it went from being the biggest fighting game of all time in terms competitive playerbase to basically having no scene at all due to covid killing lan tournam…
> I wonder if this comparison is what caused nintendo to cease and desisted an online melee tournament that intended to use rollback.
No, Nintendo famously doesn't bother to understand or pay attention to details like this. Their higher-ups can't be embarrassed because they barely understand the very concept of networking, let alone how it affects their own online multiplayer, let alone the distinction between delay-based and rollback, let alone how such a distinction might manifest in a foreign tournament on the far sign of the world. Nintendo's lawyers, on the other hand, are predictable: advertise anything about a modded game of theirs and the C&Ds come out. It's the same reason they went after Project M.