[HN Gopher] Math breakdown: Anime homing missiles
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Math breakdown: Anime homing missiles
Author : ibobev
Score : 275 points
Date : 2023-02-02 18:14 UTC (4 hours ago)
(HTM) web link (blog.littlepolygon.com)
(TXT) w3m dump (blog.littlepolygon.com)
| Voltage wrote:
| Great article! I didn't know about Rotation Minimizing Frames or
| the double reflection method.
|
| I've run up against the issue of unexpected twisting of splines
| at work more than once.
| TheRealPomax wrote:
| They're also known as Frenet frames, or Bishop frames, if
| you're going to dig into them in the future.
| PaulHoule wrote:
| There is a whole area called 'pursuit theory' about how to guide
| a missile to a target that produces very interesting curves.
| iamwil wrote:
| My first job out of college was working for a lab that did stuff
| for Air Defense. We did stuff like missiles that shot down other
| missiles for the Navy. Anyway, in my naivety, I asked the more
| senior engineers why we don't shoot missile plumes. Lots of cheap
| missiles in the hopes that one hits. (I didn't mention the idea
| was from watching anime.)
|
| They told me that the backfire from the exhaust of one missile
| might ignite the one behind it if we did stuff like that. That
| said, I've seen videos of ships firing missiles in relatively
| quick succession. Just not like the Itano Circus, however.
| [deleted]
| supercheetah wrote:
| It's not a bad idea. It's just a practical reality of their
| interaction with each other that causes a problem that's hard
| to workaround.
| User23 wrote:
| The MX sort of did that on the reentry side.
| bhhaskin wrote:
| It makes far more sense to do something like that in space
| instead of in the atmosphere. You could spread the missiles out
| a little before ignition. But you would also need some kind of
| swarm logic and tracking to make sure they don't bump into each
| other.
| cjbgkagh wrote:
| The UK Starstreak anti-aircraft missile has 3 submunition darts
| to improve hit probability. There is nothing wrong with the
| idea per se, you can design around backfire. The Metal Storm
| gun has multiple munitions stacked in the same tube.
|
| I figure the problem is more that it's hard to scale down
| missiles to the point the plume would make economic sense.
| bob1029 wrote:
| One well-guided missile can be infinitely more effective than
| 1000 poorly-guided missiles.
|
| Unless you are seeking a penetration aid against defenses, I
| don't see much point. There are far cheaper ways to deliver
| mass on target if you simply want to spam the enemy.
| Pxtl wrote:
| This video should probably have an epilepsy warning based on
| those strobe-light explosions. I adore the strobe-lights and they
| make me nostalgic as hell for early-'90s 3D games like SNES
| Starfox and Lightspeed/Hyperspeed, but the technique was retired
| for good reasons.
|
| As for the effect itself, I wonder if it would make sense to try
| this with a boid algorithm so they move as a "flock". Most
| attempts at anime=missiles I've seen either just look too chaotic
| or the missiles while initially launched at wide angles gradually
| consolidate into a tightly-packed blob.
| BoppreH wrote:
| If the article left you with an itch for a space mecha game with
| missile barrages, here's a suggestion: Strike Suit Zero[1], or
| its arcade version, Strike Suit Infinity[2].
|
| It's cheap, short, with memorable gameplay and a lovely
| soundtrack[3].
|
| [1] https://store.steampowered.com/app/209540/Strike_Suit_Zero/
|
| [2]
| https://store.steampowered.com/app/234160/Strike_Suit_Infini...
|
| [3] https://www.youtube.com/watch?v=2eDWgwucK5w
| [deleted]
| allenu wrote:
| Really cool! I always wanted to see a shooter that made use of
| the Itano Circus style. I always imagined it would be fun and
| stylish to fly around dodging missiles like that. Is there a
| shooter out there that does that?
| prova_modena wrote:
| Older games, but "Omega Boost" and "Zone of the Enders" 1 and 2
| are great examples of trying to realize this style.
| vlovich123 wrote:
| I'm curious what plotting tool the author used to create those
| slick illustrations.
| crispisulcans wrote:
| Cool design! I would love for some folks who are into this stuff
| to try their hands at this missile defence programming game
| https://openprocessing.org/sketch/745415 (click the </> button at
| the top)
| mcnichol wrote:
| Can I just say, only being a portion of the way through the
| article, you are a natural teacher/communicator.
|
| You have a very kind, knowledgeable, and effective way of
| explaining.
|
| I'd like to point out how much I appreciate how you introduce
| technical specifics and elaborate concisely enough that those who
| know and those who don't can share an article without feeling
| talked past or down to.
|
| One persons opinion. With your communication style a high bar
| I've been pursuing for some time, I just want to share a sincere
| appreciation for it!
| Arrath wrote:
| The end result does look very cool
| bee_rider wrote:
| It definitely looks neat.
|
| I don't really see the point of doing this for one target per
| missile (other than aesthetics which is a perfectly valid
| reason!)
|
| But, if multiple were heading at a single target, I guess they'd
| be harder to dodge? Multiple trajectories and all that.
| tstrimple wrote:
| Not just dodge, but it would be harder to counter them all with
| flak or Close In Weapon Systems (CIWS) as well.
|
| https://en.wikipedia.org/wiki/Phalanx_CIWS
| Armisael16 wrote:
| The real-life reason for this wild spiraling behavior would be
| that the launch tube isn't pointed directly at the target and
| the missile overcorrects. That's actually how the sidewinder
| missile got its name.
|
| This kind of mid-flight course change is a characteristic of
| real missiles in other cases , though:
|
| * almost anytime a submarine or ship launches, the missile goes
| straight up for a little bit to clear the ship before sharply
| turning
|
| * if you shoot a guided missile straight up unguided to clear
| terrain (eg a hill) before turning on guidance you'll see this
|
| * cruise missiles in the gulf wars famously did this by
| following the street grid - even turning at street light
|
| * if you launch a torpedo in a random direction then activate
| guidance later it can disguise where you are, since the torpedo
| is coming from a different direction
| magila wrote:
| I always assumed the Sidewinder missile was named based on
| the snake's ability to sense prey by thermal radiation.
| MonkeyMalarky wrote:
| Apparently HIMARS rockets do it too to avoid counter-battery
| fire. In videos from Ukraine you can see them launch at one
| angle then change direction after clearing a good distance
| from the launcher.
| paganel wrote:
| The Russian Onyx missiles also have an interesting-looking
| initial phase of the launch [1]
|
| [1] https://youtu.be/2-22myhg_nE?t=9
| sdmike1 wrote:
| > cruise missiles in the gulf wars famously did this by
| following the street grid - even turning at street light
|
| That's fascinating! Do you have more info on this?
| scotty79 wrote:
| I think they behave a bit too wild in the first stage of
| flight.
|
| I think I'd create separate launch animation that smoothly
| morphs into this flight animation.
| MrLeap wrote:
| I like using PID controllers for this kind of thing. They make it
| easy to get "authentic" looking behavior. By tuning the params
| you can adjust to behave anywhere from smooth like silk to wild
| overcorrections.
|
| They look really lively, I'll post a video on twitter or
| something.
|
| https://en.wikipedia.org/wiki/PID_controller
| TheRealPomax wrote:
| Yeah but now you made tuning the PID parameters your day job =(
| MrLeap wrote:
| If tuning to taste gets old, just use an infinite series of
| PID controllers to tune your PID parameters.
| fho wrote:
| I just read
| [this](http://brettbeauregard.com/blog/2011/04/improving-the-
| beginn...) yesterday. It details the effort that went into
| making the Arduino PID library more robust compared to the
| "beginners PID".
| rilindo wrote:
| The term for this is Itano Circus, made famous in Macross
|
| https://www.youtube.com/watch?v=pgwORRFIiuE
| grimgrin wrote:
| And here's 20 minutes of Itano Circus
|
| https://www.youtube.com/watch?v=BzXfVgYCxWI
| YeGoblynQueenne wrote:
| Cheers. Now I have to think of a way to model that kind of
| thing shooting out of a Stormsurge:
|
| https://warhammer40k.fandom.com/wiki/KV128_Stormsurge?file=K.
| ..
| jvanderbot wrote:
| To be fair, some of the "circus" aspect could be explained by
| noise in the tracker, rather than noise in the launch
| direction or trajectory tracking (as TFA proposes). Mostly I
| say this because the directions tend to diverge more as they
| get closer to a highly dynamic target.
| nvader wrote:
| I've also heard it called Roboteching, from the samish
| reference:
|
| Warning info hazard tvtropes :p
|
| https://tvtropes.org/pmwiki/pmwiki.php/Main/Roboteching
| SigmundA wrote:
| I have to believe Itano Circus was inspired by Saturn rocket
| fireworks, at least that what I though as a kid.
|
| https://www.youtube.com/watch?v=IS_7nY19kXw
| jvanderbot wrote:
| I think I should be watching more Macross
| 082349872349872 wrote:
| These are sometimes worth frame advancing for easter eggs. DYRL
| in particular had a sequence where mid-circus (IIRC) a Kirin
| beer can goes one way, and a Budweiser can goes in the opposite
| direction.
|
| [Edit: https://www.youtube.com/watch?v=wckZcVFLU24
| 4:54 anime girl as missile nose art 5:40 not kirin, but
| "hataiko" (hataiko?) 5:41 defo budweiser (also from the
| Valkyrie?)
|
| I was wrong, but not badly mistaken. There may be more; I'm
| stopping here.]
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(page generated 2023-02-02 23:00 UTC)