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Skateboard Tricks and Topological Flips

arxiv.org

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Re: Skateboard Tricks and Topological Flips

#51

Post by joncrane »

fokinsean wrote: post #14
joncrane wrote: post #9

So what are the 4 tricks? Kickflip, heelflip, flip + shove it in the "natural direction" (e.g. varial kickflip, 360 kickflip), and flip + shove it in the unnatural direction (e.g. hard flip)?

I'm guessing it's kickflip, heelflip, bs shuv, and fs shuv. Your definition leaves out varial heels and inward heels. Edit: On second thought I'm still not sure, I saw this in the paper, and I'm guessing they're classifying both direction shuvs as the same, and kick/heelflip as the same Below we list these four tricks with their corresponding residue class in Z/4Z. 0 ↔ Ollie 1 ↔ 180 Shove-it 2 ↔ 360 Shove-it 3 ↔ 540…

Maybe the four tricks are:

Ollie

Any Shove it/varial with no flip

Any Flip with no shove it

Any flip + shove it combo

?

Re: Skateboard Tricks and Topological Flips

#53

Post by psychomugs »

fokinsean wrote: post #23
psychomugs wrote: post #22

Earlier quoted context omitted.

Popping, i.e. hitting end of the board on the ground, to get height is the difference. A pop shuvit will be higher while a non-popped shuvit may barely leave the ground. Popping can actually make it easier to keep the axis of rotation closer to the center of the board.

Right, I know the difference between pop/non-pop in action, but the animations look the same. Also "shuvit" distinction is just a synonym

The transformations are only rotations; the vertical translation in the animations is just hardcoded as a half-period of a sine wave.

Setting the `vertical` flag to `False` in skateAnimation.py:generate_frames removes the pop.

Re: Skateboard Tricks and Topological Flips

#54

Post by fokinsean »

jwilber wrote: post #50
fokinsean wrote: post #48

Earlier quoted context omitted.

That's awesome! The site seems down for now but I'll check again later. Also I'll go ahead and plug the site I'm helping rebuild. https://skatevideo.site

Yo! That’s awesome you’re working o skatevideosite! O just read your guys interview on Jenkem [0]. I used your old data years back for an article for The Pudding [1] years ago - invaluable resource. Growing up I would spend so much time on the site just finding music and skaters. If there’s an issue board or something please plug it, would love to contribute! [0] https://www.jenkemmag.com/home/2021/08/16/meet-minds-b…

Woah! That's so random, I recently came across your article a few months ago. Great work and small world :)

I have a private discord and github for the project I can add you too. I eventually plan to open up the discord for anyone once we get a little further in the rebuild.

Wish there was a good way to DM on HN, I can send you a discord invite. Or if you happen to be on slap let me know.

Re: Skateboard Tricks and Topological Flips

#55

Post by volta83 »

nathancahill wrote: post #16

Generated the animations from the repo linked in the paper: https://imgur.com/a/SJcAvHF The specific tricks with their matrices are here: https://github.com/holomorpheus/topological-flips/blob/main/...

Really interesting to see the hardflip animated vertically but the inward heelflip isn't.

I always did hard flips as varial kickflips, but with fs-shuv instead of bs-shuv.

Re: Skateboard Tricks and Topological Flips

#56

Post by ndnxmsm »

rawling wrote: post #24

> As a last example we will describe the hardflip. This is a simultaneous half kickflip (a 180 degree rotation about the axis joining the tail to the nose of the skateboard) and a 180 degree rotation about the x-axis in the right-hand orientation. Is it? Isn't a hardflip just a mirror of the varial kickflip they describe, and rotation around their x-axis something else entirely?

The biggest difference in hardflip à is where your back foot is in relation to the board during the flip.

Re: Skateboard Tricks and Topological Flips

#57

Post by scudd »

eunoia wrote: post #34
fokinsean wrote: post #32

Here's a fun one to debate with your skate friends, nollie and fakie tricks are "swapped". For example: - nollie fs 180 and fakie fs 180 (fs half cab) are two different directions: nollie fs 180 is in front of you and fakie fs 180 is behind you going blind - nollie 5-0 and fakie 5-0 (fakie switch nosegrind) lean differently on the grind: nollie 5-0 you pop off your nose and land on your back truck, fakie 5-0 you pop…

Ah don't forget the same variation of foolery that comes around if you 180 into a grind. What most people would call a nose grind or 5-0 is inverted if you 180'd into it. > And remember, never carry your board by your truck :) I miss skateboarding :). My ankles don't though.

I always thought names like "180 nosegrind" made no sense. Why not "180 switch 5-0"? That seems so much more intuitive.

It made so much more sense when I learned a lot of these tricks were first invented in the 1980's, when most boards had an obvious nose versus tail difference. Like this one:

https://i.etsystatic.com/6865693/r/il/f51835/361296329/il_15...

So even though you we're grinding in a switch 5-0 looking position, you would be clearly grinding on the nose, hence "180 nosegrind".

Re: Skateboard Tricks and Topological Flips

#58

Post by scudd »

psychomugs wrote: post #35
fokinsean wrote: post #32

Here's a fun one to debate with your skate friends, nollie and fakie tricks are "swapped". For example: - nollie fs 180 and fakie fs 180 (fs half cab) are two different directions: nollie fs 180 is in front of you and fakie fs 180 is behind you going blind - nollie 5-0 and fakie 5-0 (fakie switch nosegrind) lean differently on the grind: nollie 5-0 you pop off your nose and land on your back truck, fakie 5-0 you pop…

Mall grabs are okay as long as you just tried something huge: https://youtu.be/THcnby6b6sY?t=88

Kinda like how benihanas are lame, unless you're shaved-head Jamie Thomas taking it down a gap:

https://i0.heartyhosting.com/skateboarding.transworld.net/wp...

From this Transworld Article:

https://skateboarding.transworld.net/photos/tws-10-most-memo...

Re: Skateboard Tricks and Topological Flips

#59

Post by magicink81 »

jwilber wrote: post #45
fokinsean wrote: post #37

Earlier quoted context omitted.

Ah yes! and One of my other favorites: On circle rails there is "no such thing" as fs overcrook, just fs nosegrind, and there is no such thing as bs nosegrind, but there is bs overcrook. At least that's how magazines seem to classify it.

And these are just for street! Transition has its own set of weird names (losi, andrecht, g-pivot, etc.), including some slight street overlaps (varial, pivot, etc.). I have a little passion project where we log pro’s tricks and interview them called 4ply[0]. The naming convention is something we always have to get right to make the logged data at all useable. I actually grew up skating with Erick Winkowski but can’t…

Thanks for the link... Read about Skate After School and made a donation. Great interview! http://4plymag.com/SAS/

Re: Skateboard Tricks and Topological Flips

#60

Post by axegon_ »

fokinsean wrote: post #32

Here's a fun one to debate with your skate friends, nollie and fakie tricks are "swapped". For example: - nollie fs 180 and fakie fs 180 (fs half cab) are two different directions: nollie fs 180 is in front of you and fakie fs 180 is behind you going blind - nollie 5-0 and fakie 5-0 (fakie switch nosegrind) lean differently on the grind: nollie 5-0 you pop off your nose and land on your back truck, fakie 5-0 you pop…

> - nollie fs 180 and fakie fs 180 (fs half cab) are two different directions: nollie fs 180 is in front of you and fakie fs 180 is behind you going blind

That is till this day(12 years since I last set foot on a skateboard) the most illogical thing. Especially when combined with board slides which were also not apparent from the start(for years on I called front side board slide back side) and from a logical perspective the lip slide names made a lot more sense. That said, I never figured out how to classify nollie/fakie board and lip slides front or back. As far as experience I also never understood why were hard flips called hard(I learned how to do them in less than 15 minutes after I first decided to give them a go).

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