Crypt of the Necrodancer has a deterministic, editable replay format. Therefore it is possible to make TASes of the game (albeit slowly).
A TAS got released today of probably the hardest imaginable speedrun category. Coda is the hardest character, unable to upgrade from a dagger, dying in one hit, dying if you ever make an invalid move/lose your combo, dying if you pick up gold and moving at double the speed of the music. The TASer (@Teraka91 on Twitter) controls two Codas at once using the same input to beat the game in under 4 minutes while satisfying low% condition (never picking up an item or using a shrine). It's recommended that you watch at 0.5x or even 0.25x speed to be able to follow it, because it is extremely fast.
Link to video
I've had (my own) replays desync in the past, so I'm a little leery about using NecroDancer's replay format.
With that said, that Death Metal fight looked awesome, and it's a shame you the person making that couldn't tennis Deep Blues at the end there.
Hey! I made this :)
The replays desyncing weren't too big of an issue. When a replay of a game you played desyncs, it's usually when recording rather than when playing, so you don't have that issue if you edit the replay directly.
That being said, there's a whole category of bugs in this game that stems from the fact that not everything is tied to the beat, and so if you go fast enough you can do things that shouldn't be possible (like attacking an enemy on the same beat that it dies on a spike trap), and with Coda's tempo, I had to slow down the replay (or rather, fast-forward slower) at certain strategic points to make sure it didn't desync because of that.
There was also a big desync problem at the very end, when I tried to record the finished run. I found out that for two of the bosses (the 2-4 Coral Riff and the 4-4 Deep Blues), there's a point where an add's movement should be deterministic but isn't, and is affected by god knows what. I had a bit of a panic until I managed to make it work just long enough to record it.
As for playing ping-pong with Deep Blues, I certainly considered it, but every time I hit it with one Coda, the other one moves away, so it would've only been possible for the first two hits after which the 2nd Coda would be too far to aggro the king. Plus, I like how it turned out a lot better.
Seeing as I have a hard time with Zone 3 as Melody, seeing this done with two Codas is incredible. The choreography is also really well done, great job Teraka.
I am still the wizard that did it.
"On my business card, I am a corporate president. In my mind, I am a game developer. But in my heart, I am a gamer." -- Satoru Iwata
<scrimpy> at least I now know where every map, energy and save room in this game is
Hey! I made this :)
The replays desyncing weren't too big of an issue. When a replay of a game you played desyncs, it's usually when recording rather than when playing, so you don't have that issue if you edit the replay directly.
That being said, there's a whole category of bugs in this game that stems from the fact that not everything is tied to the beat, and so if you go fast enough you can do things that shouldn't be possible (like attacking an enemy on the same beat that it dies on a spike trap), and with Coda's tempo, I had to slow down the replay (or rather, fast-forward slower) at certain strategic points to make sure it didn't desync because of that.
There was also a big desync problem at the very end, when I tried to record the finished run. I found out that for two of the bosses (the 2-4 Coral Riff and the 4-4 Deep Blues), there's a point where an add's movement should be deterministic but isn't, and is affected by god knows what. I had a bit of a panic until I managed to make it work just long enough to record it.
As for playing ping-pong with Deep Blues, I certainly considered it, but every time I hit it with one Coda, the other one moves away, so it would've only been possible for the first two hits after which the 2nd Coda would be too far to aggro the king. Plus, I like how it turned out a lot better.
Hi Teraka! Do you know if there's any resource for Necrodancer where deep mechanics and bugs are documented? There's the wikia, but it's sparse on specific information.
I know Bard used to have lots of bugs related to going really fast - I think it let you avoid trap damage, for example? - so it's pretty interesting to me that the game isn't programmed to simulate what happens in a beat the moment you press a button, but rather some things are simulated in real time.
I'm stuck at Aria's starting zone, myself. I need to get back into practice.
Invariel: For me, I find All Zones Melody easier than just Z3 or Z4 by itself, even with the reduced starting health, because you're coming in with most-if-not-all of your run gear by that point. That and the whole "I'm in the mindset of pathing so that I'm not getting boxed in" thing.
Hi Teraka! Do you know if there's any resource for Necrodancer where deep mechanics and bugs are documented? There's the wikia, but it's sparse on specific information.
I know Bard used to have lots of bugs related to going really fast - I think it let you avoid trap damage, for example? - so it's pretty interesting to me that the game isn't programmed to simulate what happens in a beat the moment you press a button, but rather some things are simulated in real time.
I don't think there's any resource for that, no. What you can do though is hang out in the CoNDOR stream and ask questions, there's always going to be people who are able to answer them (it's a weekly competitive racing thing, follow @Condorleague on twitter to get the stream announcements)
Alternatively, we also have a discord with a #theorycraft channel made specifically for asking weird questions.
As for the glitches you talk about, the way I see it is basically that not all animation lengths are synched with the beat, which means that if the song is going fast enough, sometimes you can reach the next beat before an animation is over. That happens regularly on Bolt/Coda, and you can trigger it very easily with Bard by mashing.
There's one aspect of this that's actually useful in a regular run, with the heal spell. The exit stairs make you invincible, so when you step on them you can use the heal spell even if it's on cooldown and not pay the blood cost. With faster characters, you can manage to use it 2-4 times depending on how fast the song is going, which means 1-2 entire hearts of regen every level.
Ok, thanks for the response. The reason I ask is because I've been bouncing around the idea of making a Necrodancer Science video series that documented unobvious aspects of the game (similar to the Hearthstone Science video series I help produce), for the purpose of using as references for the wiki, and wanted to make sure I wouldn't be going over stuff that was already documented.
So I guess what I should do is join that Discord channel and ask questions about stuff I want to do videos on - if the answer is known but not documented, I can make the video very easily.
The Heal Spell exploit is really cool. I'm going to have to try that next time I play.
Hey, it's me again!
For those interested, I just put out a commentated version of my run here. (It's 2h10 long though)
It goes over how I created it in the first video, and then it's mostly just showing the process of completing each level, with a bit more commentary on some stuff that's not necessarily obvious when you just watch the run.
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Dredging up this old thread for a bit, would this game be a candidate for a game specific TAS framework for the purposes of submission? I'd love to see a TAS of this published on the site but I lack the time to make it happen myself and I'm hoping someone can do it for me, heh. Have there been any newer TAS's of the game?
Hi, I'm the original creator of the TAS, changed names (and gender) a couple years ago!
I did not expect this to get dug up! Glad I still had the notification up ^^
The vanilla game has issues as I mentioned... ow... 5 years ago that makes TASing it kind of a pain in the ass, however there's been a fan-made complete remake of the game called Synchrony that has been going on for the past few years. They've reprogrammed the game from the ground up to the last details (as far as what is currently implemented) and it seems to work very well. I think if there is enough interest they have the best chance of being able to implement a TAS mode into Synchrony, and probably the people most interested in potentially TASing the game.
I haven't been involved with the community in a while, so I don't know whether there's been any newer TASes, but for my money, your best bet for getting an actual answer is to go ask the Synchrony folks over in their discord: https://discord.gg/nFwGb4SzYF
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Valkhiya wrote:
I think if there is enough interest they have the best chance of being able to implement a TAS mode into Synchrony, and probably the people most interested in potentially TASing the game.
Oooh, do you know if Synchrony works in Linux? If so, libTAS may be an option - would you have any interest in taking a look? I... really shouldn't take on another project what with all the TASBot work ahead but I sure would like to see this done right. :)
Synchrony *runs* in libTAS, however is very prone to desyncing from my experience. As far as I know its because Synchrony will occasionally lag and drop inputs when loading in new sprites and the like, though I only tried TAS-ing Bard (the character who moves at his own pace, regardless of song) so the 1-frame inputs tended to desync fairly often, though a char who's bound to the song playing could probably have the direction button held down for longer to prevent desyncs like that? I've been meaning to look into it but been busy with other stuff lately.
Technically the original game also has a Linux version that might work better, though I haven't been able to get it to run in my VM.
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Hmm... Or perhaps use libTAS and the built in replay system simultaneously? So many bad ideas, heh. Is anyone willing to try a modern version? Likewise, if the game is open source perhaps we can improve things. :)
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We had some very good conversations in the Synchrony Discord server about improving determinism. The issue is it's possible for multiple events to happen at the same time that are then not handled consistently, as well as lag spikes that may impact input. The devs are on board with making improvements, which is awesome. Valkhiya, you may want to join the Synchrony Discord server as well as there are some fun conversations afoot. :)
I'm lurking in there quietly, not really interested in making a new TAS to be honest, I really don't want to go back to the headaches of trying to figure out how the tech behind making TASes works. If it's pure routing and it's a smooth experience (read: I have access to savestates), I might get tempted, but otherwise I don't have the energy to go back into that kind of work at the moment.
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Valkhiya wrote:
If it's pure routing and it's a smooth experience (read: I have access to savestates), I might get tempted
Ooooh, allow me to tempt you even further than the devs already have! :)
For context for others, one of the main devs (Marukyu) replied to Valkhiya on the Synchrony Discord with "I'll see if I can throw together some TASing tools with full map vision and undo, which should be able to produce some pretty fancy-looking replays". In essence, it amounts to making full in-game TAS support with all of the features you'd expect. I'm excited to see so many awesome things coming together here!
