[HN Gopher] Fluid Simulation Pendant
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Fluid Simulation Pendant
Author : sschueller
Score : 460 points
Date : 2025-01-13 13:50 UTC (1 days ago)
(HTM) web link (mitxela.com)
(TXT) w3m dump (mitxela.com)
| asplake wrote:
| Charlieplexing:https://en.m.wikipedia.org/wiki/Charlieplexing
| arilotter wrote:
| I learned recently that Charlieplexing is kind of like the
| discrete version of the Radon Transform:
| https://en.wikipedia.org/wiki/Radon_transform
| Archit3ch wrote:
| Does it send MIDI?
| byearthithatius wrote:
| Or we could just fill the same container with....water
| CamperBob2 wrote:
| I'd be tempted to fill it with water with something dissolved
| in it to make it more conductive (and probably more viscous),
| _and_ include LEDs whose brightness and /or color reflects the
| conductivity at their location. The rationale being, why should
| I do all that math when Nature will do it for me?
| lopis wrote:
| Isn't that precisely his first idea? A device containing a
| conductive liquid (mercury) that takes care of closing the
| circuits and the turning on the LEDs.
| burnte wrote:
| Water is a lot less luminescent than LEDs. I think the effect
| might be reduced if changed to a water based display.
| addled wrote:
| What about a fluorescent dye with one (or few) UV LEDs on the
| edge facing inward to illuminate it?
|
| Maybe not "better" than OP's design, but could be interesting
| in its own way.
| coolius wrote:
| i was wondering whether this could be hardware accelerated.
| ImHereToVote wrote:
| At such a small scale it will not slosh around satisfyingly.
| LolWolf wrote:
| wait, this is amazing !
|
| I am tempted to make a slightly sillier version of this w/ a
| circular lcd rather than the uhh retro-cool smt leds honestly
| just to avoid the multiplexing design
|
| great work!! super cool
| mncharity wrote:
| > access to a lathe is a fundamental human right
|
| A teacher once told me their (middle? high?) school was the last
| in their state with lathes. Something which couldn't be created
| there today, and couldn't exist now in some other states, but
| which had been repeatedly grandfathered, since its creation with
| many others, just after World War 2. And that it would disappear
| upon the first serious accident, leaving none at all.
| bsder wrote:
| Access to a CNC mill and a CNC lathe should be a fundamental
| right.
|
| Being CNC with an enclosure mitigates 99+% of all the safety
| issues and makes them 1000% more useful. With CNC, the most
| harmful injury is likely to be a broken bone because you're
| only in the envelope with servos active but not the spindle.
| With manual, the spindle or chuck can grab you and kill you or
| send shrapnel into you.
|
| And I really wish we had a good, open source pick and place.
| Those still can't handle 0201 components and higher density
| BGAs even though those PCBs are really cheap nowadays.
| nox101 wrote:
| I really wish they'd repurpose public libraries for this.
| int0x29 wrote:
| No we need public libraries
| Waterluvian wrote:
| I mentor at a public high school that has a dozen metal lathes,
| a half dozen wood lathes. Plasma cutters. CNC everything. A
| giant planer. My favourite thing is that half of it is super
| modern and half of it is indestructible WWII surplus, which
| looks really cool mixed together.
|
| I cannot imagine the concept of lathes being taken out of
| schools because of accidents. What a self destructive cultural
| attitude.
| PessimalDecimal wrote:
| People are good, maybe a little too good, at assessing the
| risks of acute instances like an injury from some equipment.
| We seem to be awful at assessing systemic risks like growing
| up without knowing to make things for yourself, and what that
| does to a society.
| ithkuil wrote:
| Sometimes it feels like people think: "Yeah what's the
| point of learning how to make things when you can buy cheap
| things made in a factory in china by some low skill people.
| If they can make that stuff so cheap it must not be worth
| that much"
| nox101 wrote:
| It only takes one student to lose an arm, face, life and
| their parents will sue the school into oblivion and start
| PAPT (parents against power tools) or something "for the
| kids!"
|
| I'm on your side that I'd rather see the tools at the school.
| At the same time, I took an auto-shop class in high school
| and the majority of students in the class were dipshits and
| were lucky not to get more hurt. The teacher managed to stop
| them just in time from trying to turn over an engine on a
| rack that would have crushed them if the teach had been 5
| second later.
| Waterluvian wrote:
| We actually did have an unprecedented accident a couple
| years back and as a result some new safety requirements
| were put in place. But no tools or access to tools were
| removed.
|
| I wonder if the culture here is different than the U.S.?
| Dipshit students are removed from these classes before they
| can get anywhere near tools. It's definitely a privilege to
| be in a shop class.
| coldpie wrote:
| > I wonder if the culture here is different than the
| U.S.?
|
| There's definitely going to be cultural differences
| between the US and wherever you're located, but be
| careful not to generalize too much from one comment you
| read on the Internet.
| gimmeThaBeet wrote:
| I don't want to generalize it but as soon as you said "if
| the culture here is different than the U.S" I thought
| "Okay yep that's why."
|
| I don't even know if it counts as culture, but the US
| inevitably seems to have such a refined sense of
| litigation and, insurance mindset for lack of a better
| term?
|
| Anecdotally, schools are indeed a prime example, we had
| cooking classes in high school that were stopped because
| of the costs to insure for it.
| petters wrote:
| I used a lathe by myself at school when I was 12 or younger.
| But we live in different times I suppose
| coldpie wrote:
| I picked some random public high school in my area (twin
| cities, MN). Here's some classes they offer:
|
| > Machine Technology 1 - Increase your knowledge and skills in
| the use of common hand tools, engine lathes, shapers, drill
| presses, milling machines, and grinders. In this class students
| will have hands-on experiences in elementary mechanical
| fundamentals and principles used in precision manufacturing
| industries.
|
| > Welding 1 - Interested in becoming a welder? Learn how to use
| the art of welding in artistic and industrial settings. Develop
| basic skills related to safety, equipment set up, metal
| transfer, gas shielding and welding various types of metals.
| This class focuses on oxyacetylene and gas tungsten arc
| welding.
|
| > Construction Trades 1 - Interested in a career in
| construction or learning valuable home maintenance skills? In
| this course you will develop basic carpentry, metals,
| electricity, and pipefitting skills along with safe usage of
| hand and power tools applicable to each skill set.
|
| I think there was a period (90s-2000s?) where trade skills were
| mostly not taught in public schools, but they're thankfully
| working their way back in.
| ayoubd wrote:
| I really love mitxela's project ideas and process videos, I
| recommend checking out his other projects as well
| NKosmatos wrote:
| Yeap, Tim is some serious maker/tinkerer/creator. Besides the
| very good hardware things he makes, there are also some other
| software stuff: https://mitxela.com/other/
| CamperBob2 wrote:
| The HN guidelines say not to complain about the formatting or
| presentation of the article, but often the page design is so
| insanely terrible that someone can't help but post a complaint
| about how they couldn't read it because X, or how it didn't work
| on browser Y, or how the information density was so annoyingly
| low it wore out their mouse or pointing finger, or...
|
| This isn't one of those posts. Good job to the author. This
| article is not only nicely written but also a pleasure to read.
| Swoerd wrote:
| I would love to see a version with wireless charging, though that
| might be tough with the all metal enclosure, perhaps it could be
| done through the front/screen section.
|
| Also, adopting the screen off function Apple watches use could be
| a cool addition, for that it would need a light sensor. On an
| Apple Watch, you can switch the screen off by simply covering the
| screen with your hand.
| ImHereToVote wrote:
| I think a plastic housing might look really nice TBH.
| polishdude20 wrote:
| This is super cool! I love the simulation aspect of it.
|
| On the same note, I've been working on a bike POV display with
| lots of LEDs and just got "live-ish" video working over wifi with
| it:
|
| https://youtu.be/hxAHBvuyqpY?si=8XraFuG_Fi54Bs7T
| mattmar96 wrote:
| Ooo nice! Looks sweet
| nox101 wrote:
| Awesome! I hope you'll post some write up or something on how
| you did it!
| polishdude20 wrote:
| That is to come! Once I get it working the way I want it
| haha. Wifi is tricky and I seem to have lost the code that
| made that video work and I reflashed with old code that
| doesn't work :(
|
| Back to the drawing board
| leephillips wrote:
| So, so beautiful. I was shocked at the price. I was expecting
| something about 10x what he's charging.
| pimlottc wrote:
| Seems like it's sold out now except for a special one at
| PS1,000. Did anyone catch what the original price was?
| scotteh wrote:
| I believe they were PS500 when I first checked (approximately
| an hour after the video was uploaded).
| ge96 wrote:
| dang, great video and nice write up
|
| I can see a good video as far as show/don't tell my stuff is
| dry/way too much info. Guess it depends verbatim tutorial vs.
| just showcasing.
| elcritch wrote:
| Fascinating that with such a simple simulation you can see grain
| boundaries like those in metals forming. Look at the second
| image, those are almost identical to what they looked like in our
| material science courses.
| m3kw9 wrote:
| put diamonds on top of those LEDs and you can sell it to rappers.
| fitsumbelay wrote:
| the whole mitxela store is t-i-g-h-t the metal shop close-ups are
| zomg :salivating-face: ...
| tantalor wrote:
| I would not use "prototype" to describe this as he did.
| titanomachy wrote:
| One sense of the word is "a first full-scale and usually
| functional form of a new type or design of a construction"
| (Webster)
| brcmthrowaway wrote:
| The led screen is disappointing
| adriand wrote:
| Fascinating video. I watched almost the whole thing without
| planning to, I got sucked in.
|
| This is one of those examples of software that reminds me of my
| struggle to understand how LLMs are passing code evaluations that
| culminate with people declaring that they are now better than
| even the best human coders. I have tried to get LLMs
| (specifically, Claude and ChatGPT, trying various models) to
| assist with niche problems and it's been a terrible experience.
| Fantastic with CRUD or common algorithms, terrible when it's
| something novel or unusual.
|
| The author creates his own version of a "FLIP simulation". I'm
| going to go out on a limb and posit that even ChatGPT's
| unreleased o3 model would not be up to the task of writing the
| software that powers this pendant. Is this incorrect? I realize
| perhaps that my comment is a little off-topic given that this is
| not an AI project. However, this project seems like an excellent
| example of the sort of thing that I am quite skeptical the
| supposedly "world-class" artificial software engineers could pull
| off.
| hackernewds wrote:
| You could go and try it out. You'd be surprised how capable the
| LLMs, specifically Claude are now at creative projects such as
| this
| UltraSane wrote:
| Claude is pretty good at writing Python programs.
| Kiro wrote:
| I've implemented fluid mechanics using Claude (through Cursor)
| and it had no problem writing the logic and integrating it
| using my custom physics engine and custom renderer.
|
| So no, I don't think your assessment is correct. LLMs shine
| when they get to implement something from scratch on a blank
| slate with clear API boundaries, whether it's a CRUD app or a
| physics simulation. Where I think they struggle the most is in
| big legacy codebases on tasks spanning multiple modules with
| lots of red herrings.
| derbaum wrote:
| The "issue" with saying an LLM can't do this is that CFD
| simulations are not actually that niche. Many university
| courses ask their students to write these types of algorithms
| for their course project. All this knowledge is present freely
| on the internet (as is evident by the Youtube videos that the
| author mentioned), and as such can be learned by an LLM. The
| article is of course still very impressive.
| btrettel wrote:
| I'm a computational fluid dynamics (CFD) engineer. Like others
| have said, I'm pretty confident basic CFD algorithms are in the
| training data of many LLMs. I would say a bigger problem is the
| accuracy of the generated simulator. A LLM would not be able to
| generate good tests. You need both tests for the math
| ("verification") and tests for the physics ("validation"), and
| LLMs can't do either at the moment.
|
| Gold-standard verification tests are constructed using the
| "method of manufactured solutions" (MMS), which can be largely
| automated with computer algebra software, but are still quite
| tedious. I know from experience. I don't believe LLMs can
| handle the algebraic manipulation here particularly well.
|
| Worse, LLMs won't be able to produce actual experimental data
| to do the validation test with. You'll need to track down one
| or more experiments from the literature or do your own
| experiment. LLMs might in the future be able to point you to
| appropriate experiments in the literature, but they don't seem
| able to do that at present. I think LLMs might provide useful
| advice when a simulation ends up not matching the experimental
| data. LLMs seem to know a thing or two about turbulence
| modeling, though I would question their knowledge of the most
| recent advances.
|
| (If you're only interested in fluid simulation for games or
| computer graphics then physical accuracy is not a priority. But
| you probably should still use MMS to make sure you've
| implemented the math correctly. MMS is an interesting technique
| that has no parallel in software testing in general.
| Abstractly, the idea is to make a minimal modification to the
| software so that you have an oracle, and the nature of the
| modification is such that the modified software passing the
| test implies that the unmodified software would also pass the
| test. This idea probably can be applied in other areas.)
| neumann wrote:
| this is so incredibly impressive. I find projects and the people
| who do this so inspiring and also deflating because while I can
| appreciate the work ethic and polymath skills needed for this I
| couldn't recreate this. I'll just have to hang back and
| appreciate.
|
| Any other similar creators with this level of polish (pun
| intended) and interests to follow?
| zonkerdonker wrote:
| If you're into the custom PCB design, I highly recommend Carl
| Bugeja: https://youtube.com/@carlbugeja He has lots of super
| interesting projects using micromagnetics, motors, flappers,
| and the like.
|
| If you liked the part where he machined the housing, check out
| Clickspring. I think it's fair to say he is the greatest
| machinist currently active on YouTube, both in videography and
| storytelling, and in actual skill.
| https://youtube.com/@clickspring
| JKCalhoun wrote:
| Don't be deflated, get started.
| _def wrote:
| I second this. I bet the creator of this would be bummed to
| read this - it's not like their skills came from out of
| nowhere, just because they're humble about it.
| Hubix wrote:
| I of course don't know your specific circumstances, but
| nonetheless I'd like to recommend you the author's own take on
| their work described in a rant titled "Spare Time and Hard
| Work".
|
| It's available here: https://mitxela.com/rants (unfortunately
| It's not possible to link directly to it so you'll need to
| scroll a little bit down to find it)
|
| I personally like coming back to it from time to time, since
| it's inspiring in it's own way for me.
| moebrowne wrote:
| Direct link: https://mitxela.com/rants#:~:text=Spare%20Time%2
| 0and%20Hard%...
| JKCalhoun wrote:
| Weirdly I am drawn to his previous idea of using an actual liquid
| (mercury) to trigger the LEDs. So much simpler to lay out in
| KiCad, no 4-layers required....
| londons_explore wrote:
| Those LED's could have been packed much closer together if one
| was willing to have adjacent LED's share a single pad.
|
| Since the LED's are all the same component and therefore heat at
| the same speed in the oven, I don't think that would cause
| tombstoning.
| ionwake wrote:
| Is this for sale? Its so cool
| illwrks wrote:
| PS1k, on his website he has a link.
| albus0x wrote:
| Such a cool project. The only thing - I wish LEDs were blue
| solardev wrote:
| This is the only piece of jewelry I've ever seen that I
| immediately crave. Wish it were still on sale!
| fasten wrote:
| This project is an incredible mix of artistry and engineering.
| the attention to detail in both the fluid simulation and the
| hardware design is mindblowing(especially the clever use of
| charlieplexing to optimize LED placement congrats!!
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