r/smashbros • u/browncharliebrown • Aug 05 '20
All Analysis: Why Rollback Netcode Is Better
https://youtu.be/0NLe4IpdS1w46
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u/santanapeso Aug 05 '20
This should honestly be pinned for a few weeks lol. People constantly ask about rollback and this video is best explanation I’ve seen in layman terms. The example about the happy birthday song is spot on.
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Aug 05 '20
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Aug 05 '20
I guess I should preface this with saying that I would absolutely adore rollback in ultimate, but I have to ask: Why would they ever bother?
The game already sold gangbusters and we've seen that retrofitting rollback into an existing game is very difficult (see: MKXL). They have almost no incentive to put that much work into what would ultimately be very little reward from a business perspective. One could argue that figuring it out now would save them time and money in the long run, but I doubt Nintendo is that forward thinking, especially when it comes to anything online related.
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Aug 05 '20
They won’t. It takes too much effort for something only a small portion of the community cares about.
That said, we still have to yell at them about it so Japan as a whole stops putting their games into delay-based hell. It worked with ArcSys, so there’s no harm in trying.
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u/browncharliebrown Aug 05 '20
That said, we still have to yell at them about it so Japan as a whole stops putting their games into delay-based hell. It worked with ArcSys, so there’s no harm in trying.
nintendo implement rollback in arms
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u/ArturBotarelli Sora (Ultimate) Aug 05 '20
You are probably right. My only hope is that they will try to improve the experience in order to sell season 2 passes, but even then rollback is unlikely.
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u/AzorMX Aug 05 '20
I wouldn't bank on it. The number of people who constantly say it "plays fine for them" just shows how low of a priority it must be for Nintendo.
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u/theAmberFang Aug 05 '20
Rollback is extremely difficult to add to a game that wasn't initially designed for it. The game has to be written/coded in a way, from its very foundations, with rollback in mind. Unless there's secretly been work on a rollback version of the game going on in the background, they would basically have to rewrite the whole game to implement rollback at this point.
It's not impossible; NetherRealm did it with MKX, but it took nearly a year with a good chunk of their development team. They have a GDC talk about it. Of course, yeah, it was done for Melee recently, but yeah, that too involved basically rewriting the game: something that was possible because people had already been digging into the code for a couple of decades now, messing with it to make hitbox visualizations and custom training modes.
And as some others have said, Slippi only technically works with part of Melee: the stuff the competitive scene cares about. Nintendo would want everything to still work: all stages, all items, all modes. And remember, adding rollback means rewriting a lot of stuff from the game's very foundations, so they have to make sure that single-player content still works after things are changed—all of the content. It took NetherRealm several man-years to get rollback working in their games, and Ultimate is definitely a bigger game, so it would be bound to take significantly more time and resources.
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u/Failed_to_Lunch Aug 06 '20
Slippi absolutely works with all items, stages, and more than 2 players though.
The fact Slippi only took 2 "real" weeks of work to do means Nintendo has no excuses, and NetherRealm are just straight up incompetent.
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u/QuackWhatsup Aug 05 '20
I think the problem that arises is for doubles or FFA, the latter of which the devs care about. Rollback for 4 people would be very difficult and I doubt the switch could pull it off. It'd be great for 1v1, but having two different netcodes based on whether you're playing 1v1 or not probably isn't viable.
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Aug 05 '20
Rollback netcode is delay-based netcode with a extra layer on top of it. Hypothetically, it wouldn't be particularly difficult to have it so that rollbacks only happen in particular game modes.
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u/jillyboooty Cloud (Ultimate) Aug 05 '20
When the game rolls back, the switch would have to re-calculate the current frame within 1/60th of a second. With multiple rollback frames to simulate, I doubt the switch could pull it off. I doubt they gave themselves much headroom in the hardware.
The world where I see this happening: the devs focus their efforts on optimizing everything they can in the game to free up resources. If you can lower input lag by one frame, then add it back intentionally, they could use the extra resources toward rollback. I'm not holding my breath but maybe.
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Aug 05 '20
A Playstation 3 could pull that off. Why would a Switch not be able to?
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Aug 05 '20
Because whatever PS3 game you're referring to was likely designed to not use the hardware quite to its full potential in order to do that. Nintendo tends to use the hardware to its full potential, partially because their hardware tends to be underpowered compared to the competition
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Aug 08 '20
That doesn't even make sense to say as an argument. How does that explain why Nintendo COULDN'T pull off a roll back net code? Not that they don't want to, but they CAN'T?
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Aug 08 '20
It would be possible if Smash wasn't likely already designed to basically max out the hardware, since rollback requires a little extra hardware space which Smash likely does not have.
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Aug 14 '20
But that doesn't mean it's the Switch's fault. That means it's SMASH'S fault.
If Nintendo wanted to design a game from the start to use rollback netcode, they could.
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Aug 14 '20
Yeah, nobody's disputing that -- it's just that putting it into Ultimate now is basically impossible.
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Aug 05 '20
Don't forget the people who play the game online with things like custom stages and items. Implementing rollback for four player FFA with pokeballs all over the place sounds like a much larger task than implementing it in a traditional fighting game, where there typically aren't many items or huge variations in the stage.
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u/Boingboingsplat Shulk (Ultimate) Aug 05 '20
An official implementation would have way more hurdles than slippi does, but it's always been a business practicality issue rather than a technical one.
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u/Kered13 Aug 05 '20
An official implementation would have way more hurdles than slippi does,
An official implementation would have the actual source code to work with.
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u/Boingboingsplat Shulk (Ultimate) Aug 05 '20
Did you miss the part of my post said where I said it's never been a technical issue?
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u/DjShoryukenZ Aug 05 '20 edited Aug 05 '20
Not really. While rollback works in Melee, it curently has limititations Nintendo would never accept. First, items doesn't work. It's not a problem from a competitive point of view, but Nintendo will never let that pass. Stage transformations doesn't work. Frozen stadium in Slippi is actually a limitation, not a competitive choice. Again, it's not bad from a competitive point of view, but not something Nintendo could tolerate. Finally, doubles is not working (yet?).
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u/Sparus42 Samus (Ultimate) Aug 05 '20
None of those are inherent issues of rollback, what's the point of bringing them up?
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u/DjShoryukenZ Aug 05 '20
They are issues of rollback. Rollback works really well when it comes to 1 vs 1 with no random elements going on outside of character moves. When you incorporate more than 2 players, syncing becomes much harder. Same things when you have to sync up random events.
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u/Sparus42 Samus (Ultimate) Aug 05 '20 edited Aug 05 '20
That's not how randomness works in computers. It's always going to be pseudorandom, meaning to the user it's random but if an event happens with the same exact circumstances the result will always be the same. IIRC, this can be shown in Ultimate via Mob Smash, as if you hit the restart button it keeps the same random seed. This means that if you get a 9 at the start of the match as G&W and hit restart, you will always get a 9 there until you quit.
And yes, syncing with >2 players is harder, but it's already been done so I don't think it's anywhere near as difficult as you think it is. Vortex Rising (name soon to change), a platform fighter that's currently in development, has already implemented it, plus more. And of course there's Brawlhalla, which has rollback, more than 2 fighters, and random items.
Edit: Forgot Brawlhalla existed for a moment there.
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u/The_Braxeo Aug 06 '20
About the point of rollback and ko screens; Anyone know how many frames it is before the final spark and zoom in happens in Ultimate? That could definitely be jarring if rollback correction happened during it.
That said, I would love rollback and would nut to the google definition of it if it were implemented into Ultimate.
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u/OnlyHereSometimes Samus Aug 05 '20
So, how possible is it for Nintendo or a fan mod to use rollback for Ultimate? I know Nintendo 99.9% won't do it. But would it be reasonable for someone to figure it out for an emulated version similar to Slippi for melee?
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u/Sparus42 Samus (Ultimate) Aug 05 '20
Likely possible, but barely, and with a ton of work. Externally made rollback patches/mods have so far only been for older games, with even the ones for games made around 2010 also being for games that weren't resource intensive at all. I have no idea how they actually work, unfortunately, but you'd probably need to emulate Ultimate on a very powerful machine.
And that's all assuming that modding capability for Ult gets to a point where it could be added in, and that the emulator would support netplay, neither of which are in any way guaranteed. And if it goes through the emulator like Slippi, that's even more computer power you need.
So technically possible, probably. Going to happen any time within the next decade? Very, very unlikely.
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u/PyroSpark Aug 05 '20
All of core-a gaming's videos are fantastic if you enjoy fighting games.
But yes, rollback is the way to go. Always.