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View Full Version : Polygon Hair mini tutorial - WIP/Crit this


Augh
06-25-2005, 10:11 AM
Hi guys.

So many people have asked about how to make the hair for my WIP girl character (link here (http://www.cgtalk.com/showthread.php?t=243459)) that I am lashing together some kind of vague tutorial to help spread the word. Poly solutions to fx problems are awesome, and more heads butting against the formula will improve it for everyone. But the character is my first outing in subd and/or organics so I am leery to hand out instructions and outline correct manners of working, without some guidance from the clever peeps ^_^ I wrote basic outlines of how it works for the modeling and map creation halves, and will take pictures and create step by steps as (hopefully) we work out the best route for the process and tune the formula.

Since the modeling part is starting out from my thoughts on the process taken from a private message at this forum, I would have to apologise for the overly conversational/casual wording, but this is quite normal for me so I apologise for that instead. I will have a wordsmith hammer it back into english if need be, but I prefer to just communicate this way because it's more fluent for me.

Thanks for your time and crits, and good luck anyone who is going ahead with their polygonal hairstyles. I hope there is something useful here for you.

Cheers!

http://img159.echo.cx/img159/4905/aughhair8ip.jpg (http://www.imageshack.us)

Augh
06-25-2005, 10:12 AM
Modeling directions post goes here.

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DISCLAIMER: I am not an authority on modeling, texturing, plugins or hairdressing. Any opinions expressed are subjective, artistic or personal evaluation based, and have no bearing on the policies of any hosting forum or url, the CIA, God, or any other organisation or persona.
St. Augh - 2005

Ok, let's see here. There's a few basic points that makes this whole idea work properly (just as info I use Max 6, tend to use editable mash which sucks and am learning to stick to editable poly more atm. Joan of Arc trained me that way)

1. Cylinders are automagically mapped. Woot! this is the biggie and what makes the whole effect work, it comes down a *lot* to the strands being mapped on there absolute/totally straight.

2. Meshsmooth is really over the top. So we can be pretty sloppy about things and it will often look more natural rather than screwed up. You'll start to see this pretty fast. My hair's unsmoothed looks a little kinked :D That's a lot of how it works. Don't be afraid of crazed angles etc.

So you probably have a skullcap deal stuck on your model's head atm. If not just throw one on there (I just extrude the required skull polys as a clone, detach that and adjust the hairline as need be, the idea is we cover this with locks so it can suck for now, it's ok)

Good idea right here is to grab a couple cute pics from an anime or cg style, where the hair is in those fatty "locks" we'll be doing. If you don't watch cartoons, best is just google image search (you use this for everything remember) for generic anime terms till you find something, then enter that series name or whatever and get on the paper trail. You have a cute 'do now? Cools hehe. This is mostly to get the hang around the face arranged pleasantly.
We're about to start creating a lot of objects so group, instance, track however is best for you, I thank god for "select element" personally. Try and group stuff into elements of an object when locks are finished to avoid having a bazillion objects with a subd modifier each. I'm no expert but this seems much less cpu lethal.

Finally on to the good stuff; Grab a new cylinder and give it enough sections along its length to work good bends into, and a number of edges around that will allow you to put just quads in the end face (will help pointy tips end cleanly) If you set material now (see directions in texture creation section for map infos) it might help, or could be confusing, so turn diffuse on and off as is best for you, same goes for the subd modifier, which we'll want to apply at whatever point is easiest to work with. Remember all this can be toggled.
There's two flavours of hair lock here, one is based on a regular cylinder just tapered along its length. The other is the same but we go to a top view and pull one row of verts inwardsto create a groove along the cylinder, pull the surrounding rows around to even it up and prevent stretching uv ;) Varying these two types along with the different maps gives a really good jumble of variation and things will start to look more natural. Whichever type of lock you make the rest is pretty much the same.
Select and scrap the top face, which we won't need cus it would be inside the scalp, and stops the root resolving properly, some also will want to delete the rows of faces that would lay against the scalp, for poly count and styling reasons. Now use a scale on each ring of verts top to bottom to taper the whole cylinder, turn on subd to get a look how it's going as you do this. I clone a few of these and keep them off to the side in randomly different scales etc to grab a new copy of each time and whack out locks more quickly.

NOTE: Add picture of lock types and stages of shaping so far here.

Grab one and rotate it so that it sticks out from your model's head like the Dr. from Back To The Future or Sonic Hedgehog, it looks ridiculous always at this point. Place near the desired parting off slightly to one side and use rotations and moves on the rings of vertices to lay the cylinder down the slope of your model's head, repeat a little offset on the other side. It's important to always perform some sort of vert moves, scale or rotations on *any* piece that you mirror for timesaving, so that it all stays good an random. Do this a few times and you will start to have a basis to add locks to, and you'll have enough volume that you can get away with cloning a few locks at a time and moving them around to make more. You can see in the pics for texture directions (NOTE: add dedicated pics with good clarity here) how the topknot is arranged, and that the hair around and behind the ears is very important.

NOTE: Add more illustration pictures here.

MORE NOTE: Add tips and elaborate on the building up process here.

-Modeling directions end here for now-

Augh
06-25-2005, 10:13 AM
Texture creation directions post goes here.

You guys can post now, I should just need these spaces. There is not much to talk about yet though hehe.

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Hell of a lot to add for this section, needs a full step by step too.

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Creating the maps is very important to the overall effect of this polygon hair, particularly the vividness of specular and diffuse maps. In the sense that this is an element you will find can be tuned to personal taste quite a bit. My maps are a little vivid but I like that style, I would recommend examining real photographs and people, CG, and traditional drawn hair in order to get an idea of the general feel of things here.

The polygonal hair in progress;
http://img128.echo.cx/img128/764/wippolygonhair4ul.jpg

Specular map;
http://img102.echo.cx/img102/5295/hairspec6ef.jpg

Diffuse map;
http://img102.echo.cx/img102/630/strands3redline6sl.jpg

Having created the maps already in a trial and error fashion, a step by step doesn't really work. The jist of it goes something like this. *IMPORTANT* - Recipe is completely prototype, adjust ALL aspects as you feel necessary. What I like might not be what you like, and I tried things very much at random anyway...

NOTE: Do a step by step for this section...

Create a photoshop brush that consists of a row of small marks, try to keep things a little varied in terms of size and scattering, but density generally saves time. Make sure that the scattering (Brushes setup dialogue, brush tip section) is dragged right down to 1, so that you can create a constant unbroken line. Now we can hold shift and drag down the
canvas in stripes (new layer here, you use layers to keep elements tweakable right? ^_^)
to create the basic strand effect. The diffuse and specular maps are both made up from
the same basis, the specular map being desaturated, recontrasted, cloud layered and
anything else that seems to help.
- Tablet users might experiment with taper and wave and other things here, but I kept it simple as the map has to work with the geometry in some fairly technical ways which will become apparent. -

Now we have a canvas of hard, harsh looking lines. It's pretty ugly and not very Clinique. I would suggest that people who are better with Photoshop and other paint programs proceed with layer masks for the next step, but I just used the eraser *shame* with a large, soft brush shape to erase out the tips and make a gentler fade effect.
The final touches involve adding noise to the strand layer of the diffuse or specular version of the map as seems best (I tried this after noting a slightly rough effect to some oriental hair, and it seemed to work quite well), and overlaying layers of Filter > Render > Clouds for variation in sheen (specular) and colouration (diffuse). My maps used a very faint blue and brown cloud layer in the end.

This should provide the texturing required to make our polygon hair more lively and less "clumpy", and provides a great deal of extra detail with a relatively low outlay of time and effort. I used up to 4 sets of maps assigned very randomly to the locks of hair in order to keep everything as natural and nonlinear as possible, also to create the red shocks through certain parts of the hairstyle. These red flashes were added afterwards with simple resaturations in PS to stripes of the diffuse map.

-End texture directions here for now-

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