[HN Gopher] Curly-Cue: Geometric Methods for Highly Coiled Hair
___________________________________________________________________
Curly-Cue: Geometric Methods for Highly Coiled Hair
Author : cainxinth
Score : 168 points
Date : 2024-10-11 13:01 UTC (3 days ago)
(HTM) web link (www.cs.yale.edu)
(TXT) w3m dump (www.cs.yale.edu)
| fedeb95 wrote:
| I wonder if this becomes relevant also in analyzing real hair,
| for designing hair-related products etc.
| amelius wrote:
| There is a trillion dollar market in hair, but it is not about
| virtual models.
| cscheid wrote:
| I once heard Pat Hanrahan (who among other things was
| involved in some of the early realistic hair rendering work)
| claim that L'Oreal funded some of that work, exactly because
| they were interested in what the models said about the
| (control of) appearance of real hair.
| SpicyLemonZest wrote:
| I'd never rule out crazy applications of math, but the problems
| seem pretty orthogonal. When you're rendering, you want to
| stipulate by fiat that the hair is perfectly healthy and immune
| to damage and holds its style no matter what the environment
| brings to bear, and those are exactly the things most hair care
| products are meant to help with.
| Cthulhu_ wrote:
| This presentation by one of the authors is a good primer on the
| current issues around Black hair and hairstyles in Hollywood,
| CGI, and video games, and why this research is important:
| https://www.tkim.graphics/MORETHAN/Darke_Slides.pdf
| burkaman wrote:
| The core issue:
|
| > There have been no papers on afro-textured hair at SIGGRAPH
| ever.
|
| There are over 300 SIGGRAPH papers on other types of hair.
| samatman wrote:
| More accurately, there are over 300 SIGGRAPH papers on
| _hair_.
|
| Slide 3, with this headline:
|
| > _Curly hair in graphics research is limited to "classical
| European locks"_
|
| Contains this phrase:
|
| > _which varies from an elongated ellipse for African hair_
|
| Which leads me to think the Eurocentricity of the other 300
| papers is being rather oversold. The Beethoven-looking
| redhead on the previous slide has two hair styles which are
| unmistakably models of common African hair textures. Being
| generous I would guess that the hair was made lighter to show
| details better? Caucasians presenting with that level of
| frizz is also not unheard of.
|
| Afro-textured hair is certainly a topic worth a few SIGGRAPH
| monographs all on its own, and a dedicated library is also
| great. But I suspect that a thorough review of the 300 papers
| in question would find that the insinuation that none of them
| treat on the subject of African hair is somewhere between
| "not supported" and "wildly false".
| wizzwizz4 wrote:
| I'm inclined to believe that the authors, if they quoted
| that, _read_ it. The implied claim is that this treatment
| is inadequate. (My reading is supported by the text on the
| previous slide: page 23 in the PDF.)
| burkaman wrote:
| I am not going to read through all 328 papers to fact check
| this, but I'm very confident they did do a "thorough
| review", that's how you start research like this. There's a
| bit more detail in the course that this presentation is
| from:
|
| > As of 2021, we only found two technical papers that
| showed Afro-textured hair [Bertails et al. 2005; Patrick et
| al . 2004]. While some technical papers containing Black
| hair have started to appear since we published our findings
| [Hsu et al . 2023; Wang et al. 2023], these usually
| represent relatively unstyled hair. Some styles have
| started to appear in short talks [Ogunseitan 2022], but a
| wide range of intricate, sophisticated, and very common
| hair styles still lie outside the visual language of
| computer graphics research.
|
| - https://dl.acm.org/doi/10.1145/3664475.3664535 (not open
| access, I can share it if you're interested though)
|
| The four papers they mention here are not from SIGGRAPH.
| The "short talk" was from SIGGRAPH 2022, but as that phrase
| implies it was a talk and not a paper.
| dahart wrote:
| One could read the claim being made as there aren't any
| papers that are _primarily_ about Afro-textured hair, nor
| about Black hair geometry considerations, which is likely
| true. There might not be that many papers that you could
| say are primarily about Caucasian hair either, but there
| most definitely is a lot of straight and wavy hair. I think
| some Siggraph hair papers do show examples of Afro-textured
| hair, IMO Darke's slides here have one (p.23, example (c))
| tkim.graphics /MORETHAN/Darke_Slides.pdf
|
| Might be worth pointing out there aren't that many siggraph
| papers on procedural hair geometry generation, quite a few
| are on rendering hair and do cover dark/black hair with
| elliptical cross sections. IIRC there are some papers on
| blonde hair specifically because it exhibits more visible
| scattering.
|
| Anyway... is there a historical/cultural bias toward
| Eurocentric hair and not a lot of representation of Black
| hair? Yes that would probably be totally fair to say.
| Splitting hairs on whether or not their words are
| unambiguously and perfectly accurate might be slightly
| beside the point. Let's take it as a hint that we can
| improve, and enjoy a paper that brings new hair generation
| methods to bear.
| IncreasePosts wrote:
| Could a non-black person even present a paper on afro-
| textured hair, without being subject to the vicissitudes of
| the social-justice-twitter-sphere?
| burkaman wrote:
| Yes they could. The paper we're discussing was written by
| non black people. Another recent paper they reference was
| as well: https://research.nvidia.com/labs/toronto-
| ai/adaptive-shells/.
| IncreasePosts wrote:
| The paper discussed has A.M. Darke listed as an author,
| who appears to be black. And that adaptive shell paper is
| not about black hair - it merely uses black hair as an
| example, along with cat hair, dog hair, leaves, and horse
| hair.
| burkaman wrote:
| Ok I don't know what to tell you then, we can't answer
| your question because there are no papers that meet your
| criteria. That's the whole point of this discussion,
| nobody has even tried.
|
| I'm assuming you won't think this counts either, but
| here's another paper they reference that includes afros,
| again written by non black authors:
| https://graphics.cs.utah.edu/research/projects/sag-free-
| hair....
| jrm4 wrote:
| Black person here; this social disconnect is of course
| something I pay quite a bit of attention to.
|
| The answer, typically, is OF COURSE. Big time. It would be
| well appreciated by most.
|
| That being said, I get where this perception comes from --
| there can be, as you call them, outsider social-justice
| folk who might try to say something weird here:
|
| But I just need to highlight the "outsider" part of that --
| if only for non-black folks to understand and to try to pay
| attention to exactly who you're listening to and getting
| authority from? I hate to use a phrase like "real Black
| people" but I'll go with that for now; real Black people
| tend to be the MOST reasonable, but often under-heard.
|
| I'm reminded of, e.g. police reform; I understand that it's
| incredibly important and necessary. Which is why
| phrases/ideas like "Abolish the police" and "ACAB" are
| _deeply_ unhelpful.
|
| (and as always, I am only one Black person, nothing I say
| here should be taken as gospel for everyone, I could be
| wrong)
| zombot wrote:
| This looks great, but 234 Kelvin is almost -40deg Celsius. Why so
| cold?
| pezezin wrote:
| In the case that people don't understand your comments:
| uppercase K is Kelvin, kilo should be lowercase k. Plenty of
| people get it wrong, even researchers and scientists who should
| know better.
| amelius wrote:
| How much processing power does this require? Can it be done in
| real time?
| chefandy wrote:
| It probably depends on what you mean by real-time. Hair isn't
| something I deal with a lot, but I'm familiar with the space.
|
| It says the top model had a few hundred thousand hairs. Doing
| real-time flat-shaded grooming in a DCC that supported this
| type of generation is likely doable. However, I haven't seen
| any real-time hair simulation that wasn't clever shader
| manipulation in a game engine or the like. It's just too much
| geometry (including constraints and self-collisions) for the
| hardware we have now while simulating everything else. And then
| you've got to shade all of those individual hairs which wuld
| have a ton of surface area. It would be super resource
| intensive.
| throwup238 wrote:
| This is more for movie VFX where rendering times are measured
| in hours per frame on large rendering farms.
| dahart wrote:
| This is for hair curve generation, so it can be done offline.
| Animation and rendering on the resulting models can still be
| done in real time, to the same degree it could before.
| karmonhardan wrote:
| The short hair example in particular is remarkably realistic.
| Immediately familiar to this guy who spent most of his childhood
| with a skin fade, and a massive improvement over the flat image
| texture or bump maps that are usually used.
|
| Because many black people (especially African-Americans) have a
| mixture of hairtypes, I expect the results to be even better once
| something like this is implemented alongside existing systems.
| jay-barronville wrote:
| I usually approach "inclusivity"-driven work with a massive
| amount of skepticism, but as a black man with highly coiled hair,
| I have to admit I'm very impressed by this research and work.
|
| I used to be really into gaming when I was younger, and a
| somewhat disappointing aspect of many games for me was character
| selection. Even when there were dark-skinned characters, I can't
| think of a single game within which I could select or build a
| character that truly looked like me (or close enough), and
| usually, it came down to the hair. At the end of the day, it was
| never a big deal and I still had lots of fun, but it would've
| certainly been nice to have better, more relatable, selections,
| so I appreciate this research!
___________________________________________________________________
(page generated 2024-10-14 23:01 UTC)