Topic by julianch

Posted: 12/19/2017 5:24 PM

Post subject: Starting my researches about glitches

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ThunderAxe31

Any

Editor, Reviewer, Skilled player (1358)

Joined: 9/12/2016
Posts: 1646
Location: Italy

I'm finally back working on Crash, hopefully without further interruptions. I'm currently researching on a glitch that makes Crash remaining stuck on air. See the following videos for some demonstrations: https://clips.twitch.tv/HelpfulObliqueNikudonTooSpicy https://youtu.be/5zvRlDMAKeQ While I already managed to reproduce the glitch in the second video, I yet have to figure what is specifically triggering it; but for the moment I can tell that the address responsable for Crash to remain stuck on air is the maxium Y speed value.

SystemID GBA
010A14	d	u	0	EWRAM	X position
010A18	d	u	0	EWRAM	Y position
010A74	d	s	0	EWRAM	max X speed
010A70	d	s	0	EWRAM	max Y speed
010E2C	d	s	0	EWRAM	X position (bonus level)
010E30	d	s	0	EWRAM	Y position (bonus level)
010E8C	d	s	0	EWRAM	max X speed (bonus level)
010E88	d	s	0	EWRAM	max Y speed (bonus level)

While Crash stands still, all maximum speeds are zero. This value gets modified if Crash stops standing still. In fact, if you poke the Y position in order to put Crash on air, the maxium Y speed value will change to 1536 in order to allow Crash to begin falling. But if you poke the maxium Y speed while Crash is still on air, the value won't change. So the reason why the glitch prevents Crash from falling, is because something made the maxium Y speed to change to zero before Crash landed. From what it seems, it's probably caused by the pushback of the boxes, or maybe I should say "pushupwards". The interesting thing is that this minor glitch of pushing Crash upwards can also be triggered by landing on the ledges of moving platforms and bonus level platforms, but with these I couldn't cause Crash to remain stuck in air. So there is probably something involved about breaking boxes as well. Edit: It looks like the glitch can triggered only if there are at least three boxes stacked. You basically need to break the middle one(s), leaving the upper and the bottom ones unbroken, and landing on the bottom one before the spin ends. At this point it looks to me that this glitch can be triggered only in very specific places.

my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"

Posted: 3/8/2018 8:15 PM

Post subject: Back again

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ThunderAxe31

Any

Editor, Reviewer, Skilled player (1358)

Joined: 9/12/2016
Posts: 1646
Location: Italy

Sorry for having paused the project again... So, continuing from when I left: I searched thoroughly for a way to trigger in stage 10 that glitch. Despite having now a better understanding of how the glitch works, I was unable to find any way to trigger it there... I'm sorry. But let's go in detail. When you land on a box, that box will break and Crash will rebounce on it. But if before landing on it you broke one or more boxes with a spin during that jump, Crash won't rebounce on the box, and the box will not break. At this point Crash will also be able to walk on that box without breaking it. I've come to the conclusion that this was a lazy workaround aganist the glitch. In fact, if there are at least 3 boxes stacked and you break the middle one(s), the bottom box will make Crash rebounce even if Crash is still spinning. But since the game does not expect Crash to be able to rebounce on *anything* while spinning, then the game freaks out a resets Crash's maximum falling speed to 0, causing him to get stuck in air almost instantly. It looks like for some reason, while a box is falling over another one, the bottom one temporarily loses the feature of being able to prevent Crash from rebouncing during a spin. So triggering this glitch is going to be impossible with less than 3 boxes stacked... Unless we find a different way to force Crash to rebounce while spinning. Note: when you land on an enemy while spinning, that enemy will be killed by spin instead. So, I had to simply re-TAS the whole Stage 10 from scratch. In the process, I managed to save 95 frames. The new WIP file desyncs in level 14. Edit: new WIP file: resynced up to level 16 complete on BizHawk 2.2.1, 30 frames saved in stage 15. Movie #45784678238323512

my personal page - my YouTube channel - my GitHub - my Discord: thunderaxe31 <Masterjun> if you look at the "NES" in a weird angle, it actually clearly says "GBA"

Posted: 2/6/2021 11:55 PM

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