Geometry Nodes Hair - Blender

Ruz

so i got so far on this , but as with xgen I want to make a distinct parting , but the clump modifier tries to push together the hair guides either side of the parting. I guess there whould be a way to use a texture map to do some kind of region control map.
Any ideas?
I did try a black and white texture map for the factor, but it did nothing

Ruz

well I re did it and was more careful where placing the parent hairs and it seems to be working better
I have a weird feeling the interpolation and the hair index can lead to weird results

Ruz

ok so I found a solution, does work reasonably well, but still you havre it where the clumps can't quite decide which side of the parting to lie
https://blender.stackexchange.com/questions/296891/sheeps-wool-type-hair-clumping-and-parting-with-geometry-nodes-blender-3-6

so yeah its similar to region control maps in xgen, but its jsut a case of painting a black line where the parting should be. it also depends where the guides are in relation to the parting, so its stll a bit fiddly

Ruz

I went back to paticle hair for styling. I guess whichever way you style the guides, its not for the faint of heart.
But I have got used to styling with particle hair and the good thing is I can convert it to geometry nodes hair afterwards,
either convert the parent and child hair or just the parent if I want to layer it up with clumps, frizz etc
I still find the new sytem a bit WIP , but I am sure they will carry on improving it
The current problem is with the clump interpolation, no good way to separate them for partings

This was done with the old method

thomasp

I find styling in all the tools I've tried deeply frustrating, only way for me to be happy is to model with curves and turn these into particle hair guides. So, styling like its the early 2000's all over again (in fact I found an old article about the 1999 Star Wars movie where they mentioned those exact same methods being used back then too ) . The styling tools admittedly do look good in demo videos but that's about where it stops for me.

Also to paint texture masks (not f**king vertex groups, thankyouverymuch) to control the various effects. Else this stuff is either not accurate enough or gets lost too easily as the mesh changes or you want to reuse maps elsewhere - at least in my process.

Not interested in playing around with beta features either - there are interesting threads to lurk in for that on blenderartists for sure - just in how to find a way to produce this stuff predictably within a deadline and budget constraints.

I agree that Blender's new implementation looks incomplete as a real solution and (still) partly inferior to the 'old' process. Made me walk away within a few days of testing it. I'll check back next year or so.

Right now the best solution still seems to be the 3d 'hair brush' addon which gives you modifiers on top of the old - dare I say 'predictable' - particle hair method.

What's with the crazy chromatic aberration in all the shots btw?

Ruz

Lol, I like Chromatic abberation, it's my new plaything like lens flares in the 90's I may tone it down a bit, but it does help focus the viewer on certain areas and hide the crappier bits.


yeah I agree with your points, producing hair is a 'really' painful process, makes me lose a lot of sleep.
I spent maybe 4 years learning how to style particle hair reasonably well and can just about do stuff I am pleased with
I have tried max hair, xgen , blender, maya and they all make me feel as though I have to become a hair specialist ( I am not)
I even got some good results with max's hair system, but it is buggy as hell and crashes all the time, so gave up
By now you would think the would have a more inventive solution to what is essentially a modelling problem. If I have the artistic skill
to sculpt hair, then I should not have to worry about how to make the shapes for real looking hair, but it is what it is

clumping is the real problem at the moment, there should be a simple way to define regions where you want a parting for example.

I am sure some Blender guru has an addon of some kind to compensate and there are a few additonal geometry nodes you can buy, but for now

I will just follow the development until its good enough

you can paint texture maps to control various things with the new system, but you have to set the nodes up yourself, but its not that difficult and is pretty
versatile.

I bought 'hair tools' a while ago and that has some good tools, so might give that a try next( he has updated the addon to use the new system)

https://bartoszstyperek.gumroad.com/l/hairtool

I tried the method of building curves separately, but it takes me a really really long time , but you can add other splines like in a max loft to give the single spline some volume, which works quite well for cartoony hair
 
I also sculpt particle hair by only using the parent hair and set the radius
quite high so they look like big planes. This really helps visualise what I am sculpting. The problem is that Blenders interpolation is really bad, so when you add the children hair its a bit inconsistent


Here are a few methods I have tried over the years, not trying to educate anyone, just trying to show my processes so far


Blender  building from curves  - with a bevel object use to control the the strands/thickness ( like a loft in 3ds max) works great for cartoony hair
works well but takes a long time. In theory you could use a bunch of thin bevel obects to simulate hair and control  with the main spline






Particle hair using only parent hair with radius of 1 or 2 cm for better visualisation. i directly plug in a color ramp to the material output.
you then have to use interpolation, but set the amount to zero and enable the children tick box in the comb tool
This is probably my easiest method and I still use it . I often use the curves in other systems like xgen, hair tools etc






Blender particle hair. Short hair is ok to sculpt, but the interpolation sucks a bit. you cannot directly sculpt the child particles like in
xgen which is a big minus - tidying up stray hairs on a new  sculpting layer would be awesome

Blender 3.6 new hair system.
EDIT
so i kind f worked out how to do the parting in the hair . Normally when you add a clump modifier, it does not do the parting correctly
Buit all you have to do assign a texture map to the factor ( or amount of clumping). I paint black where i don't want the  clump( ie the parting ) and this fixes it. refer to my first image I posted above to see the problem where the sub clumps do not know which guide to belong to, so they create a bunch of smaller distorted hairs







Native 3ds max hair system, crashes more than windows 95 . It was actually surpsingly controllable, but lots of features missing.
Despite being in very early version of max. they did not really update it in 20 years.  if only they cared I made this in about 2009 I think





zbrush hair sculpting using fibremesh. this system is a bit awkward in my opinion, you can't add new hairs as you are going along
but I did get some useful curves out of it in the end. A bit too quirky for my liking




so yeah I know a lot more about hair, but still i find the whole process very frustrating .probably the main reason
I gave up on doing characters TBH
It's like trying model a crash helmet out of a bunch of sticks
added this one. I had waay too many parent hairs, so started deleting  a bunch to make it more manageable

you can see the areas I need to fix

thomasp

Sounds to me like you are treating hair as one object. In my experience you'll have to break up the hairstyle into several chunks for it to become manageable and apply different particle systems. Putting a parting exactly where you want would be trivial to achieve this way.

Clumping in default Blender is a disgrace, you'll need to check out the 'Hair Brush' addon (not Hair Tool - that's mostly for hair cards although the curves to particle hair function is helpful here).

That one will give you xGen-style modifiers you can layer:

https://www.youtube.com/watch?v=Z_cDvzP7aTs

In my experience modelling the guides as curves does indeed take a lot of time (you need a lot of those to get around dodgy interpolation) but pays off in the end since I have full control over the shape and can assign them anyway I like to different parts of the hair without fear of losing work if particle modifiers change.

Making hair is simply a big task, not something you can wing in an afternoon like most demo videos seem to suggest. IME, anyway.

Ruz

yeah , when I finally got around to doing each selection separately like top of hair side of hair etc , it instantly became more manageable and almost fun to work with. I have tried this before with particles hair obviously, I just wanted to make it a bit more manageable and was hoping the interpolation was good enough to make it work with 1 big chunk , but I was wrong
To get the same modifiers for each new bit of empty hair I just used link tansfer data/ copy modifiers

I actually have that hair brush addon, but was not really sure of the benefit, might give it another try with the update
fun times

JoseConseco

As dev of Hair Tool, I know that making hair with split is pain.  The way It is solved in blender geo nodes, was to use loose mesh island for parting of hair (no need to paint texture, or vert group). I used this method in Hair Tool  - you just cut or split edge, and this creates parting.

You can repeat this to get smaller 'hair islands' 
I also added one click option to pick and select guides belonging to given island (you just click on island, and guides that are spawned on that island are selected ready for combing).
I could not though of simpler way than this.  On top of that you can add child system which will follow these parted guides (u can add any effect on these - curl, clumps, braids etc). No need to setup any masks, textures etc. 

Ruz

@JoseConseco Hi , I own Hair Tool and am going to go through the new features next week. looks pretty good, but I have been too lazy to
test it out so far
In the mean  time I kind of have  a  solution of sorts, where I 'slide' the roots around until the weird parting disappears in the area where the parting goes. works ok. 
also sometimes you dont want a hard parting, but to overlap clumps from either side
I did try spitting edges which did work to a degree, but if it's part of the same mesh , it still tries to grab hairs from the other side
also depends on the interpolation distance. I really hate that feature

I tried working on separate meshes like top , sides, nape etc, but foud it a real pain to keep the density consistent

ironically i am doing some really good stuff with particle hair now, just as they are stopping the development of it

This my current method using particle hair. I jsut make my own clumps by selecting groups of hair, which you can now save the selection for

JoseConseco

@Ruz - sliding points is the way I do it too, see vid:  
https://youtu.be/6r5zUOxpO7c?t=987
This is the only way to get more organic hair split line. 
The disadvantage is though, you have to convert fully procedural hair to 'real' curves thus you loose some ability to tweak e.g. their density. 
How do you select store selection for particle hair? 
I did not encounter any issues like problem of interpolation distance,  issues with density or child following strand from one island, going to the 'other' side.  But then I do not use particle hair or default hair nodes, so yes, maybe they have those issues. 

Ruz

@JoseConseco looks cool, looking forward to messing aorund with that.
So particle hair has some basic functionality for storing selections now.
In the tools section of the comb brush there is a hair group option. it is supposed to also colour each group, but does not work.It does store the selection, but you can't seem to rename them.
its a nice little additon, but i tend to select on the fly,  using the arrow keys to select and deselect the hairs i need ( once I have selected the intial bunch of hairs)
i think I will probably switch to yuor new system once I get the hang of it as I will still have to output my hairstyles as polys at some point anyway

yeah the defualt hair system still has issues, but maybe they will fix them at some point?
EDIT The split polys method does kind of work but only using the 'Exisiting Guide Map'. if you uncheck that it stops separating by mesh islands

EDIT
Actually I kind of made it work. you set the factor to 'guide curve index' and it works   but the problem then is it won't really let you layer the clump modifiers, you either seem to get lots of clumps or not so many, both with a parting and no weird crossovers

JoseConseco

@Ruz these are using default  blender hair nodes right? I found them bit convoluted, so In HT  I have rewritten them from scratch, and I do not have these issues (at least I did not encounter it for tenths of hairstyles I made). 
Nice hair and character btw. 

Ruz

yes these are the default hair nodes , using version 3.6 of blender. I am sure there is some way to fix this stuff, but this system is still in Beta
so they might have it covered( hopefully)
TBH I still prefer sculpting with particle hair, then converting afterwards( either to hair tools or now the new system). I just wanted to learn the latest system in case I need it at some point

Ruz

@JoseConseco so I have had a lot of fun using the new hair tool, but have a few issues. For example i converted particle hair to curves , then added a profile , then hair setup node. I can then use most of the hair tool system, but on some of them, the slide tool does not work.
it will only let me slide some of the guides or sometimes it will just say i have a missing mesh
is that a bug or did I do something wrong?  if I add new guides I can slide them around, but not the existing ones

JoseConseco

@Ruz - I think you do not linked the new curves linked to source mesh (scalp) - if so you should see error in 'Surface deform' modifier "missing rest position" or something like this. 

Try: select curves, then source mesh:  ctrl+P -> attach to surface.  Blender needs this for some operations. 
Btw. I do not get notifications from this thread (not sure where do I set email notifications).  But faster support on HTool - try using HTool Discord channel