[HN Gopher] ZOZO's Contact Solver for physics-based simulations
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ZOZO's Contact Solver for physics-based simulations
Author : vintagedave
Score : 62 points
Date : 2025-10-30 15:21 UTC (7 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| jayd16 wrote:
| This seems to be the relevant Two Minute Papers with a very quick
| explainer.
|
| https://m.youtube.com/watch?v=VOORiyip4_c
| embedding-shape wrote:
| Was Two Minute Papers always so sensationalistic or is that a
| recent change? I remember seeing the videos many many years
| ago, and don't recall him being so overly enthusiastic and
| borderline sensationalistic, like this video seems to be.
|
| Even the title of the video is straight up clickbait ("The
| Worst Bug In Games Is Now Gone Forever") since the context is
| all wrong, the metrics on the top left even shows "time/frame:
| 3.38 min", how could that be useful for games? The problem with
| physics in games is in real-time simulations, not in
| cached/animated "physics".
|
| Don't get me wrong, the simulations are impressive, and
| hopefully will have a big impact on simulation stability for
| real-time and not, I was just taken aback by the video.
| makach wrote:
| hey, what a time to be alive
| zokier wrote:
| He has been like that for couple of years at least. I guess
| it wins clicks in the youtube slot-machine. But I can't stand
| him either, despite being exact target audience for his
| videos.
| MintPaw wrote:
| I used to watch his videos early on, but it's been like this
| for a few years at least.
| embedding-shape wrote:
| Same here, that's why I was kind of surprised. Shame what
| YouTube forces creators to degrade into, I remember it
| being super nice being able to see a video about a new
| SIGGRAPH paper before diving into the details, but these
| new videos (well, "new" if what you say is true about it
| being years) I can barely stand because of the change...
| littlestymaar wrote:
| FYI you're responding to a 3-days-old account with way too
| many comments in such a short time frame to be legit. It's
| most likely a bot.
| embedding-shape wrote:
| Lol, thanks I guess, but I'm just bored and have lots of
| free time :)
|
| Also, based on my first message in this submission, how
| on earth (like exactly) would an LLM or something else be
| able to leave a comment like that? Do spambots on the
| internet have entire backstories now or what?
| GuB-42 wrote:
| It has always been his style, you can check for yourself by
| watching some of his early videos. Over the years, he has
| refined it and fully committed to it.
|
| I usually don't like too much sensationalism, but he gets a
| pass. That's just his style and I think he does it well
| without compromising on the information content. He
| acknowledges that the technique is slow by the way, but
| that's late in the video.
|
| But I agree that the title is poorly chosen in this case and
| I think it would be more appropriate for the previous video
| about a similar paper [1] where the simulation is less
| accurate, but runs in real-time. It is as if the titles were
| swapped.
|
| [1] https://www.youtube.com/watch?v=7NF3CdXkm68
|
| Edit: And of course, it is entertainment, what did you expect
| of a YouTube channel covering state-of-the-art research in
| less than 10 minutes! If you want to get serious, read the
| actual paper. Short(ish) YouTube videos is simply not the
| right format for serious work, sensationalism or not.
| jayd16 wrote:
| Yeah, love it or hate it, I do think they thread the needle
| between genuine excitement and overhyping.
|
| The titles and thumbnails are getting clickbaity though.
| zokier wrote:
| > Short(ish) YouTube videos is simply not the right format
| for serious work, sensationalism or not.
|
| I disagree. For example SIGGRAPH presentation videos manage
| to be short, informative, and largely non-sensationalist.
| You can see some of them in this playlist: https://www.yout
| ube.com/playlist?list=PL1PdIP1lGMJJzRFjlDajK...
|
| StiffGIPC presentation makes good contrast here:
| https://www.youtube.com/watch?v=3TBoTX2vag4
| andai wrote:
| His catchphrase is literally "What a time to be alive!"
| ivanjermakov wrote:
| Not realtime, seconds-minutes per frame.
| totallymike wrote:
| Is your comment here to refute a claim you saw somewhere, or to
| simply point this out? I wouldn't expect this to be real-time,
| given the complexity, nor do I believe it needs to be in order
| to be useful.
| erwincoumans wrote:
| It is good to point it out it is for offline simulations.
| There is some related recent work, Offset Geometric Contact
| that is suitable for interactive use:
| https://ankachan.github.io/Projects/OGC/index.html
| embedding-shape wrote:
| Also assumed by default we were talking about real-time, but
| then I saw Python/juPyter and a rendered videos, got a bit
| confused, then came across "46.4s/frame" for one of the
| examples and finally registered it wasn't about real-time.
|
| I agree it doesn't have to be real-time to be valid, I think
| my mindset just goes to physics in video games which are
| usually real-time when I see contact solvers or most other
| things related to simulations.
| fnord77 wrote:
| Contributors:
|
| claude 19 commits, +21,000 lines
| moritonal wrote:
| That's quite a bad faith take when you'd have seen claude is
| used at the very end after 10 months of another author's work
| with +62,847 lines.
| SecretDreams wrote:
| Contact is a hard problem to solve and there's some tangential
| softwares that do it well within the FEA space. I'd be curious to
| know how this does with materials/geometries of vastly different
| stiffnessess and if it produces realistic reaction/contact forces
| (one cheap way to manage contact is to jack up the contact
| stiffness, which will prevent penetration, but drive some
| unrealistic forces at those interfaces).
| suioir wrote:
| What value do all the emojis provide?
| Y_Y wrote:
| They made me stop reading halfway through.
|
| It didn't help that they make meaningless claims like
|
| > Physically Accurate: Our deformable solver is driven by the
| Finite Element Method.
|
| I don't know or care if they used an LLM to write that readme,
| but it's hot garbage. A pity because it seems like a decent sim
| otherwise.
| cutlilacs wrote:
| What's wrong with that statement? FEM is a good way to handle
| deformables, but it isn't the only way, so it a fine
| statement.
| Y_Y wrote:
| It's used as a claim of physical accuracy, but it's not
| related to that.
| twright wrote:
| joy.
| zparky wrote:
| yeah its pretty funny, i wonder if they prompted the llm to put
| as many emojis in as possible:
|
| <edit> forgot hn doesnt show emojis, so ill just link to the
| paragraph: https://github.com/st-tech/ppf-contact-
| solver?tab=readme-ov-...
|
| 8 emojis in 2 sentences, lol
| zokier wrote:
| If I'm understanding correctly, the same approach was implemented
| also in IPC Toolkit here: https://github.com/ipc-sim/ipc-
| toolkit/pull/148
| adammarples wrote:
| I can't quite figure out how to install and use this. Perhaps it
| would be useful if I could install it as a python package, by
| providing a pyproject.toml or something? I ran warmup.py which is
| creating venvs for me and doing all kinds of things I don't
| really want, but when activating the environment it still failed
| on 'from frontend import App', which seems to be commonly used in
| your examples.
| DarmokJalad1701 wrote:
| Holy emoji batman!
|
| Shirt shells? Tree stump solids? Knot rods?
|
| I have no idea what any of those mean.
| rossant wrote:
| The LLM knows.
| stronglikedan wrote:
| Fun fact: In Haiti, "zozo" is a slang term for male genitalia.
| avidiax wrote:
| For those that don't know, ZOZO is a tech-forward clothing
| designer/retailer.
|
| Several years back, they sent me a special spandex shirt/leggings
| combo, black with spaced white dots. Then you use their app to
| take many photos of yourself, and they have a profile of your
| body to be used for automatic fitting.
|
| The shirt they eventually sent did fit well, but wasn't anything
| special several years ago.
|
| This shows that they are still at it, and as someone that hates
| shopping for clothing, I hope this is a sign that the dream of a
| custom tailored fit at a mass production price is getting nearer.
| ris wrote:
| If they ever get liquidated I wonder who's going to end up with
| that massive dataset of photos of people looking like a tit.
|
| Or perhaps they'll pivot..
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