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The Implementation of Rewind in Braid

The Implementation of Rewind in Braid on HackerTube: recommended by 2 Hacker News commenters across 2 separate months, 2018–2023.

GDC Festival of Gaming

talk · intermediate · evergreen

Open on YouTube

Jonathan Blow's GDC talk explains how the time-rewind mechanic in Braid was designed and implemented, including the technical hurdles such as memory limits and state history. It covers both design and engineering concerns.

Why Hacker News recommends it

HN commenters cite it as the reference for how a rewind system works and as a point of comparison for undo and serialization approaches.

people recommended it
2
separate months
2
strong recommendations
0
discussed on HN
2018–2023
“Here's a GDC talk about the rewind system in which he explains some of the hurdles he had to deal with”
— AnIdiotOnTheNet, Mar 2023, in ““Clean” Code, Horrible Performance – Casey Muratori [video]”

What HN commenters said

6 Hacker News comments link this video. Each one links back to its thread.

OnionBlenderNov 2023Recommends

If you're curious how the time rewind was implemented, Blow did a GDC presentation back in 2010. ▶ this video

in “Braid, Anniversary Edition trailer [video]” · View on HN

m00nAug 2018Recommends

Seconded. It was a great game, albeit with not so much replay value. There is a great interview with Blow on the technicalities of the warping effects in Braid: ▶ this video In addition to Limbo and Inside, may I also recommend: Portal 1&2 Antichamber VVVVVV increpare.com In particular Stephen Lavelle (@increpare) makes games with much darker and more interesting social implications. Although, Braid accurately predicted the "nice guys" trope.

in “Braid 10th anniversary critical compilation” · View on HN

AnIdiotOnTheNetMar 2023Cites it

> I don't think that's an earned position. I disagree. > You say he has more credits but only one of those is programming since Braid. He did start a company after that you know. A successful one that makes money and employs people to make art . I don't imagine that running a business takes no time from his life. > But even at the time Braid could have been written in python SDL wrappers and probably had similar performance Braid did a lot more than you give it credit for. Here's a GDC talk about the rewind system in which he explains some of the hurdles he had to deal with: ▶ this video Pay particular attention to the discussion of the background particles and how to get that to work within the RAM constraints. > On the other hand, on a software engineering level those paint by numbers Modern Warfare and FIFA games are both more technically impressive and are designed for fast iteration Hardly anything about these games change from release to release. They're not exploring new gameplay problem spaces, they're not doing anything super interesting or surprising on a technical level either and I don't get why you think they are. Of course if you keep using essentially the same engine and know exactly what you're trying to make, making another like a goddamned factory is going to happen quicker than if you're trying to make something unique and meaningful. > If clean code is about maintenance and time to market, the Blow paradigm hasn't proven that its needed or fixes the holes in cl

in ““Clean” Code, Horrible Performance – Casey Muratori [video]” · View on HN

hbnAug 2022Cites it

Is difficulty of implementation really a reliable indicator for the complexity in players understanding the mechanic? Jonathan Blow did a talk[1] at GDC a few years ago about implementing the time rewind mechanic in his game, Braid. It ended up being a pretty complex system that required a lot of ingenuity to come up with a design and implement it, but the end result is pretty straightforward and easy to understand for players. [1] ▶ this video

in “From throwaway side project to Switch in 2 years: my indie gamedev story” · View on HN

steeleduncanOct 2021Cites it

It is interesting to compare this to Jonathan Blow's talk on the rewind system in Braid [1]. This stores complete game states using a compression library to keep memory under control, whereas Braid stored a combination of keyframes, and diffs from those keyframes, to avoid using a compression library. [1] ▶ this video

in “Serialization-Based Undo” · View on HN

MillenialManOct 2021Cites it

I don't really agree. Cache friendliness is almost always a relevant factor as soon as performance becomes an issue. I get what you're saying but as I see it immutability gives you architectural efficiency and in some cases space efficiency, but rarely processing speed. > Think video games like braid Braid doesn't use immutable data structures, it uses a historical record (and immutability would be incompatible with some of the mechanics).[1] The author of Braid is actually quite famous for his dislike of functional languages and immutability. He doesn't even like garbage collection because of the overhead it introduces. Interestingly, he was talking about data structures for codebase representation (in the context of a compiler) a while back, and someone mentioned HAMTs. I'm definitely curious if they would work well there. [1] ▶ this video

in “Idiomatic Clojure without sacrificing performance” · View on HN

Topics & tags

Game programming & enginesGame designbraidjonathan blowrewindundo systemsgame programming