The Implementation of Rewind in Braid
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.
What it is
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.
Recommended by 2 HN commenters across 2 different months, 2018 to 2023.
What Hacker News said
Recommends m00n · 2018-08 · on “Braid 10th anniversary critical compilation”
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.
Recommends OnionBlender · 2023-11 · on “Braid, Anniversary Edition trailer [video]”
If you're curious how the time rewind was implemented, Blow did a GDC presentation back in 2010. [this video]
Cites steeleduncan · 2021-10 · on “Serialization-Based Undo”
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]
Cites MillenialMan · 2021-10 · on “Idiomatic Clojure without sacrificing performance”
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 repres
Cites hbn · 2022-08 · on “From throwaway side project to Switch in 2 years: my indie gamedev story”
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]
Cites AnIdiotOnTheNet · 2023-03 · on ““Clean” Code, Horrible Performance – Casey Muratori [video]”
> 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