View Full Version : need some help w/ maya hair

11 November 2009, 10:12 AM
So I'm working on something for my demo reel and trying to get past the novice stage of working with Maya hair and unfortunately it doesn't seem like there's too many good resources as far as dvd's and tutorials that aren't so "entry level". Right now I'm getting to the end of the styling stage, and trying to get some test renders and dynamics tests. What I'm having problems right now is with my collisions, I've set my start and rest curves, but when I render it seems like the hair is penetrating each other. So figure I set it to self collide, but what that does is just make my hair kind of explode and get tangled, and it seems like my passive follicles become a complete mess. I havent really worked with having hair self collide, and could use some tips from experienced hair dynamics artists.

Also if anybody knows of any in-depth training dvd's, tutorials, books, etc. on Maya hair dynamics, I would really appreciate some recomendations!



11 November 2009, 06:18 PM
You're right, definitely not many resources for hair. Digital Tutors has a pretty entry level disc (maybe more now) on hair. There was a great Autodesk series disc on hair that came out around Maya 7 I believe, but not sure if it's still for sale.

I haven't used self collide enough to give any good answers, but the value might be causing it to freak out. Some of these values can be quite sensitive, definitely depending on scale.

Maybe post a playblast, or some screenshots to help us help you?

11 November 2009, 07:20 PM
I personally recommend nCloth for any hair dynamics.
You're life will be a lot less difficult simulating inside the nCloth enviroment.

create thin strips of polys from your hair curves.
apply nCloth
then wrap your curves to the poly strips.

You don't even need to make thin strips. Depending on the style of your hair you select a number of hair curves and loft of nice clean sheet of poly. Also you can create a number of different types of mesh and constrain them together to help maintain certain looks of the hair. You just have way more control over every aspect of the simulation. And nothing beats nCloth collision detection.

11 November 2009, 07:35 PM
heheh well hello Scott :)

I agree that this is a great way to go. I guess I'm thinking down the line if he actually needs to use hair dynamics (depending on the facility the nCloth method isn't used).

JP we can help with the road you're already going, but if you want to try something newer, then go for Castius' method as it works quite well. If you've never used nCloth it might be daunting, but from a sim standpoint quite solid.

11 November 2009, 09:59 PM
Whats up Dax 8)

You are right nCloth does have a high learning curves. But much less limitations. For basic motion the hair dynamics are suitable for a lot of tasks.

11 November 2009, 04:34 AM
Yeah dax I've actually gone through the Digital Tutors and the Autodesk one you mentioned. I actually found the Autodesk one to be the most informative, and the others including Digital Tutors, a Gnomon dvd(which seems like is no longer available), and a few online tutorials weren't very in-depth.

Castius, thats actually really informative and makes sense. I have some familiarity with ncloth, so I wouldn't hesitate to try this method out. I'm actually looking forward to it as I can already tell it will be much less of a headache. Just curious, is this nCloth method whats actually used out there in majority of the studios?

As far as what I was saying about the hair penetrating each other here's a render of what I was talking about, circling the area where the hair was penetrating other hair.I figure I could work on the curves to model the hair out better but that wont do anything to simulations. This is before I used self collide.

I kind of have a handle on it now though as I've moved back to an older file when I was using dynamics to style the hair and set self collide on earlier. Works a lot better after making adjustments to settings, but I do still get a tiny bit of "tangling" in the simulations.

11 November 2009, 06:11 PM
Oh well then you've pretty much seen all there is for hair training that's out there ;)

If you are familiar with nCloth then by all means follow what Scott says. It's a very good method. Some facilities change their workflow depending on the show. But generally Sony and Digital Domain (simming right now lol) do not use the nCloth workflow. I believe IMD
might, ILM does not, Disney doesn't, and don't think Dreamworks does. Game studios might use this far more. I guess it also depends on what your end goal is. Trying to get into hair career-wise? Or just interested in this working for your reel?

How are the curves modeled? Are they starting out by intersecting from the get-go?

11 November 2009, 07:41 PM
Awesome, thanks for the info Dax.

As far as how the curves were modeled out, they weren't intersecting from the beginning, but as I used dynamics to further "relax" the hair, thats when they started intersecting. Also I noticed some of my passive follicles weren't being affected by any nearby dynamics follicles, so I had to model some more dynamic curves in. Those probably started intersecting the other curves somewhere in the mix. So thats when I tried going back to an older file and setting self collide on before "relaxing" the hair. That seemed to work a lot better but I think I need to tweak my settings as well as my workflow out some more.

Right now I'm just interested in this working for my reel which is more of a Character Artist/Generalist. Going through school, my specialty was more of a character modeler, but those can be found under every rock, stone, nook, and cranny, so tried to broaden my skill sets and found that I really like doing hair. Career-wise, I can actually see myself doing hair.

Question, being a Hair TD, did you find that it was necessary for you to have cloth sims on your reel? I ask, cause I notice almost all the job listings are for cloth/hair fx. Sorry for all the questions, but I do appreciate all the info you guys have given out. =)

11 November 2009, 07:53 PM
No problem at all.

Admittedly I haven't used "out of the box" hair for a long time, but I do recall those settings can be VERY sensitive. Even now, something like a .1 is great, but .2 can blow up depending on what attribute.

Well I can say if you decide to go into cloth/hair for a career it is greatly in demand, and the supply is not too big. All the big shops generally need it at this point, and lucky enough to not really have a break yet since switching over (was FX).

Yes, generally cloth/hair always go together. Sometimes you'll be broken out into smaller teams, but department wise they are together. I just put hair TD at this point because the show I'm on (Tron!) we're not simming cloth due to the style. But I have both cloth and hair on my reel for sure. No problem at all for the questions, happy to help. And as you've noticed, not a huge amount of cloth/hair info out there ;)

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