I had several people ask how I do hair, so I put this together. It's not really a tutorial so much as 'teaching by example'.
First off, I've got the 4 maps I made (so far - I may make a gloss map, not sure). Sorry, I'm not sharing them. You'll have to make your own hair maps.
I've got the Color(diffuse) map, the normal map, that I created using CrazyBump (google it). Then the Spec map (also made using Crazybump), and the alpha map.
I literally created one big plane and applied the whole map to it, and then proceeded to cut out each individual piece of hair and separate them into their own individual objects.
Then I gridded up each piece so that they could be deformed easily.
Let me state for the record, that this is too high res and dense for most games. Not that game consoles couldn't push this many polys - just that most game studios wouldn't throw away so many polys on one characters hair. Maybe a main character, but only that one character would ever get this much love and polys
Okay, so I had every individual bit of hair off to the side, untouched.
I would duplicate one of the pieces, move it over to the head and start placing it.
I put 3 bend modifiers on most of the hair pieces.
You just have to mess with it to learn what you like and what you need. Different hair styles will require different techniques.
Oh yeah, and make sure you've got a bunch of photo references up somewhere (like, on your 2nd monitor if you have one) of the hair style you're aiming for. It'll come out so much better if you have something to look at and reference.
Okay, so I just did it over and over and over and over and over again.
A zillion planes, overlapping and bending in different directions.