Even though I performed the zipping glitch once and kept it all the way, instead of re-colliding the chipmunks each time, the lower route is more lag-prone (because you end up having more enemies on the screen) and I spent more time in the air by doing small jumps to keep chipmunks collided. This TAS is effectively 15 frames slower and my final position is worse because there are 3 levels of crates I need to cross.
Zone O1. Top floor, upper route at the beginning.
I tried taking the upper route once I reach the end of the second vertical pipe. For this, I didn't sacrifice a chipmunk for the other one to use it for a vault and performed a zipping glitch instead.
Unfortunately, you can't jump over a such a big target as a mechanical dog. The only way out is to jump down where Aglar takes the lead.
Aglar manages to keep the route optimized while keeping the chipmunks on the edge of the screen, although it's not appropriate, because, at some point of zipping, the game may randomly push you in the opposite direction or stop you. I don't know why this happens.
Still, using such position, he manipulates luck by making the mouse above the tall block of crates jump away, hence making less creatures on the screen afterwards.
Zone O2
User movie #638525257538743066
No, taking the lower route to have zipping glitch for more time doesn't save time, because the mouse jumps over the crates and hits chipmunks.
User movie #638525258334574985
Also, there is no way to perform one long fall right after executing zipping glitch. One chipmunk lacks one unit of X position and lands on the very edge of the crate instead. If I delay the drop, I get hit by the mouse on top.
Maybe something will be discovered in the future, but I think Aglar has probably found the potential limits:
1. A jump to an upper platform (64 units higher): video moment.
The way to do this is, one chipmunk does a minor jump, the other chimpunk performs a jump of a specific length (of holding A button) and you can achieve stability by making the collision push both chimpunks straight up, without giving any X momentum to cause resonance. This way you can reach the shown level of height. After this, the game separates the chipmunks on their way down, but here they already land on the upper platform and the state of collision survives.
Also, Aglar's very first jump with zipping preservation is just hilarious. He manages to handle the collision in the way so Chip lifts up in the air without jumping.
2. A 39-units jump-landing while preserving the state of collision: video moment.
If you check inputs, you'll notice that both jumps with collision preservation and throws to reach the state of collision (zipping glitch) are patternized for different conditions. One step aside makes chipmunks separated.
To summarize, maybe an improvement there exists, but I haven't found it in 6 days of testing and examinations. I think Aglar's TAS is indeed optimized.
UPD: fix video links
TASing is like making a film: only the best takes are shown in the final movie.
Joined: 4/17/2010
Posts: 11495
Location: Lake Chargoggagoggmanchauggagoggchaubunagungamaugg
Nice work! Video links don't work tho.
Warning: When making decisions, I try to collect as much data as possible before actually deciding. I try to abstract away and see the principles behind real world events and people's opinions. I try to generalize them and turn into something clear and reusable. I hate depending on unpredictable and having to make lottery guesses. Any problem can be solved by systems thinking and acting.
The first is box ascension:
https://twitter.com/junkyard_dave/status/1710927985409503655
Basically, the chipmunks can gain height if they jump and throw boxes at each other. I TASed out a logical section this could be used in a TAS (F2) and you can ascend very quickly on the vertical scroll. I'm not 100% sure, but each chipmunk might have to have the same subpixel (didn't test if this was true - but sometimes ascending would just fail on me with proper inputs) but, if that isn't true, likely what is true is lag frames. There was 5-6 lag frames in F2 that I had to rework basically the inputs around, which immediately makes this strat likely non-RTA. Still, for real TASers, this I feel is a legitimate time save and could be used in F2, as above, possibly D (depending how the invisible wall interacts in D3), Zone 0 climbs and possibly the A climb with some extreme wizardry.
Thank you very much again for finding it and sharing your input file with it!
I got your permission to share it, so here it is: User movie #638551165200464645
The point of this trick is to utilize the mechanic of states. When the animation of throwing is initiated, a chipmunk cannot be stunned by a box flying at him. However, the flying box still collides with his hitbox, making him to ascend by a small hight.
Yes, in order to perform this trick, you need to have equal Y subpixels for both players and keep a certain distance between them. Under these conditions, the ascension power is much higher than under normal circumstances, and this lets you move up even faster than by rapid jumping.
The only problem is to get equal Y subpixels. Unfortunately, they are recalculated on each frame (except the case when a chipmunk is being carried by the other one), making it very hard to get continuous equality of subpixel values. Even if you achieve it, you cannot do any kind of platforming or else you lose that equality.
For this reason, F2 looks the only time-saving spot that's effectively useful.
As Dacicus described the mechanic of calculation of Y-subpixels:
$460 is changed by the value at $550 and $510 is changed by the value at $560. The value at $550 is itself modified by the value at $99, which seems to be fixed at 0x55. Same thing for Dale, but with addresses $551 and $561.
I'm working on a full game TAS and I've successfully achieved this trick, but the optimization could be better. User movie #638549446456416825
After several, exhausting hours of bruteforcing, I managed to get equal Y subpixels on the frame I enter the hole to F2. This TAS is 40 frames slower then the fastest completion of Zone F1.
If you want to help me optimize it and you're ready to sacrifice some time on it, please notify me! All info is described there. I didn't manage to improve it, so now I just go on.
UPD: the TAS is finished is submitted!
#9150: Dimon12321, Aglar & dragonxyk's NES Chip 'n Dale: Rescue Rangers "2 players" in 08:43.47
TASing is like making a film: only the best takes are shown in the final movie.
