[Bf-committers] Hair Sculpting and Simulation

[François T.]

hey,

from a post I did a little while ago :
http://www.francois-tarlier.com/blog/blender-vfx-wish-list-features/

[Bonus] Hair Simulation
> This is not directly VFX related but as I understand, you had trouble with
> hair simulation on Sintel. I did talk about it with Daniel Genrich at the
> time, because I think he is the dynamics guru who could nailed this kind of
> thing. So I gave him a few papers to look at which he thoughts were very
> interesting and not very hard to implement, but as I recall it was too late
> to implement at that time and you guys didn’t have enough time to do it or
> even take the risk to test it. But I guess it is not too late for next
> projects.
> When I was working on face tracking/recognition at Ubisoft, I met someone *(Basile
> Audoly <http://www.lmm.jussieu.fr/~audoly/>) working on mathematically
> modeling the dynamics of hair*. He gave us a demo which was very
> impressive. And if I’m not mistaking, he has been working for l’oréal
> research after that [image: :)]
> His program was able to model curly, straight, dry, wet, growing,… hair,
> but also dynamic cutting, all those features model in his research. I have
> personally seen his demo, and I have never seen something so real, see by
> yourself with the video !
> Here are the papers and videos :
> Super-Helices for Predicting the Dynamics of Natural Hair
>
>    - *video* :
>    http://www.lmm.jussieu.fr/~audoly/research/hair06/HairDVDVideoQT.html
>
>
>    - *paper* :
>    http://www.lmm.jussieu.fr/~audoly/research/hair06/BA_hair_siggraph06.pdf
>
>
>    - *Predicting Natural Hair Shapes by Solving the Statics of Flexible
>    Rods*
>
>
>    - *paper* :
>    http://www-evasion.imag.fr/Publications/2005/BAQLLC05/BertailsElectronicFinalEG.pdf
>
>
>    - *publication* :
>    http://www-evasion.imag.fr/Publications/2005/BAQLLC05/
>
>
>    - *video 1* :
>    http://www-evasion.imag.fr/Publications/2005/BAQLLC05/astaticStrandEG05.mpg
>
>
>    - *video 2* :
>    http://www-evasion.imag.fr/Publications/2005/BAQLLC05/fullModellingEG05.mpg
>
>
>    - *Basile’s Website* : http://www.lmm.jussieu.fr/~audoly/
>
>
cheers ,

F.




2013/12/19 Lukas Tönne <lukas.toenne at gmail.com>

> Hi Hsuan-Hao,
>
> Having a dedicated hair solver would be great. The same code is currently
> used for particles as well as hair, with "fake" cloth data being generated
> in addition to that for hair dynamics. This is a very cumbersome and
> complicated system, where the exact use of the data has to be checked in
> almost every function.
>
> Particles will get a replacement next year. This leaves us with the option
> of removing/disabling the particle code from the current system and turn it
> into a pure hair feature, but eventually the whole thing should be recoded.
>
> As a rough outline, these are the steps i would suggest:
>
> * Implement a dedicated data structure for hair. Atm the geometric model
> for hair is based on spline interpolation, with "particle paths" being used
> as the control points. But there are a number of more suitable models
> around, e.g.
>   - Modelling hair as strands, which supports very detailed curling without
> much additional data [1]
>   - Volumetric hair [2]
>
>   I'm far from being up-to-date on all the methods being used in the
> industry at this point, a thorough investigation of available methods is
> needed.
>
> * Integrate hair dynamics into a general simulation framework. This is
> another part of the planned physics improvements for next year: We want to
> solve the problems with object interaction by moving away from the current
> use of "modifiers" as the basis of simulations. I've written down a few
> thoughts on why this is a problem and how it can be solved by adding a
> scene-level simulation framework at [3].
>
> * Adapt current sculpting/particle edit tools to work with the new hair
> data structures. Ideally the sculpting tools should be generalized in a way
> that allows use with different types of geometry where applicable, such as
> surfaces (2D), "strands" (1D) and point (0D) data. Special hair features
> such as curl parameters may still require specialized brush types.
>
> Regards,
> Lukas
>
> [1]
>
> http://hal.archives-ouvertes.fr/docs/00/52/02/70/PDF/finalcoursenotes2008.pdf
> [2] http://graphics.pixar.com/library/Hair/paper.pdf
> [3]
>
> http://wiki.blender.org/index.php/User:Phonybone/PhysicsRoadmap#Simulation_Framework
>
>
> On Thu, Dec 19, 2013 at 8:15 AM, 張軒豪 <pyrochlore at gmail.com> wrote:
>
> > Hi all,
> >
> > My name is Hsuan-Hao Chang and I am new to this mailing list.
> > I am specially interested in 'Hair' in Blender.
> >
> > The hair sculpting tools in Blender is amazing but I want more.
> > Since Blender is open source, I decided to build some tools.
> > For example,
> > brush to orient strand of hair without change the shape,
> > utility to transfer hair shape from one to others,
> > roller helps create curl hair like Disney's Brave,
> > etc...
> >
> > Before that, I think it would be a great idea to ask the project owner
> and
> > everybody here first for advices.
> >
> > Also, I am interested in hair simulation.
> > >From the source code, I found the current 'hair simulation' using an
> > implicit cloth solver.
> > I have gave it a try, but the behavior of collision is not easy to
> control.
> >
> > Will we have any plan to implement a real hair solver?
> > If we do have a plan, I want to do some contributes on that.
> > It would be a necessary if we just made a great hair style and want to
> > animate it.
> >
> > Regards,
> > Hsuan-Hao
> > _______________________________________________
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> > http://lists.blender.org/mailman/listinfo/bf-committers
> >
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François Tarlier
www.francois-tarlier.com
www.linkedin.com/in/francoistarlier