There are many parts to maya hair dynamics and this tutorial covers the initial styling of it. In this tutorial I create the hair from pulling splines off a nurbs surface and use the history on the surface to control the shape of the hair. I create my hair this way because I've found it to be the best way to style the hair and have the most control over it (constraints and simulations are so tedious for basic styling). If i have enough time at some point and enough people are interested, I'll cover rest curves and constraints and the true 'dynamics' of hair but, not in this tutorial. Once the style has been created, simulations can be run for whatever animation purposes.
Here we go...
We need to define the area of the hair. A good way to do this is to draw curves and loft them into a nurbs surface. Start off drawing a curve and placing it all around the edge of where you want the hair to be.
Here I have all my basic curves in place. I'm not completely happy with the shape so i'll use clusters to control groups of CV's to help fine tune my shape.
Here are the curves after some adjustment.
Now select all the curves and loft. At this point you can delete the curves you made or stick them in a layer and forget about them. We're modeling with history here so any isoparms we pull off this surface will control any ammount of new curves we make as well as the final hair.
Now select isoparms from the nurbs surface. Make sure you space them out evenly from where the root of the hairline is so there's no gaps on the scalp.
Once you have all your new isoparms selected, Duplicate Surface Curves.
Here's our hair shape.
IMPORTANT - you should duplicate this to the other side of the head. For the purpose of this tutorial I'm only working with half the head. If you only work with half the head, you can select the hairs at the end and mirror them to the other side but when you reload the scene, the hairs will be gone so it's important to assign a hair system to the entire head.
We're ready to assign a hair system to it. This is a round about way to do this but it works. If we select a curve and 'assign hair system' it wont connect the paintfx to it so we need to create a sphere, assign a hair follicle to it, use that follicle to assign the hair system then delete that follicle and finally the sphere. Sound confusing? It's not as bad as it sounds.
Create a sphere. With the sphere selected go to Hair>Create Hair Options. The settings dont really matter all that much, we're using this as a dummy object we'll delete later.
We use this to transfer the hair system to our curves. Select all the curves that you previously made and go to Hair>Assign Hair System>hairSystemShape1
You should end up with something like this.
At this point, we can remove the sphere and the hair follicle. Dont delete it yet though, we must remove the follicle by painting it out first. To do this select the sphere then go to Hair>Paint Hair Tool Option and change paint mode to Delete Follicles.
Now paint over any hair follicles you have so remove them. Once they're all gone, you can delete the sphere.
Select the strokes and under the attributes of hairSystemShape you can set the general properties of your hair
If you've turned your flatness up like I did, you may notice some of your hairs are not rotated to the angle you like. To correct for this, select, one at a time, the troublesome hair curves and in the attribute editor go to follicleShape and change the Clump Twise Offset.
At this point I'd like to adjust the general shape of the hair a bit. Thankfully I dont have to edit the curves, I can select my nurbs surface and it will control everything for me.
After a bit of shaping, im satisfied with my hair for now. And I'm ready to move onto the pigtails. I'll make these the same way as i made the rest of the hair. I'll draw some defining curves, loft my surface around them, then select isoparms from the surface and duplicate surface curves.
I'm not completely happy with the shape of this so i'll use the nurbs surface to reshape them a bit. This time I'll use a lattice to edit all the shapes rather than one at a time.
At this point, you can either assign your current hair system to these new curves or, like we did earlier, create a sphere and assign a new hair system that we can use with this.
Here I have assigned a second hair system to my pigtails because i want the ends to have a different 'thinning'.
Voila! Hair. Now it's just a matter of fine tuning the shape and adjusting the hair attributes to get the desired look.
