Generating hair alphas from zbrush sculpt
polycounter lvl 14
Hey all.. I know the title of this thread sounds ridiculous and you're probably thinking "What the? WHY?".. but let me explain what I'm trying to accomplish, if I can.
I'm working on a Troll ceature for a baldur's gate mod and I finally got around to starting work on it's hair.. I'm generally not a fan of using alpha'd hair... I like to see it while sculpting in zbrush so I can get a better idea of the final result.
So I was originally leaning toward sculpting the hair for this creature, when I thought... why not make a strand, duplicate it, move it around a bit, duplicate, move, etc... and then pinch the roots (slightly, only to group them a bit) and then really pinch the tips to bring them together.
Played around with this for a bit the other night which resulted in several subtools of clumped together hair strands which look pretty much exactly how I would want the hair to look if I was using hair planes. It would be easy to retopolgize each "clump" of hair seperately by just extruding the edges of a plane out along the hair and just beyond the tips of the clump.
My question is... what comes next? I use xnormal to generate normals/base texture painting in zbrush/ao... and I'm wondering what you guys think the result of baking the highpoly hair clump to the planes would be.
Could I fill the hair strands with a flat white color in zbrush and then bake the base texture to the flat geometry? Would it provide me with a suitable alpha for the hair?
I've attached examples of the character. Please let me know what you think! Is this a crazy hair-brained idea? Or might it actually work? I'm at work or I'd give it a shot right now!
Thanks!!
I'm working on a Troll ceature for a baldur's gate mod and I finally got around to starting work on it's hair.. I'm generally not a fan of using alpha'd hair... I like to see it while sculpting in zbrush so I can get a better idea of the final result.
So I was originally leaning toward sculpting the hair for this creature, when I thought... why not make a strand, duplicate it, move it around a bit, duplicate, move, etc... and then pinch the roots (slightly, only to group them a bit) and then really pinch the tips to bring them together.
Played around with this for a bit the other night which resulted in several subtools of clumped together hair strands which look pretty much exactly how I would want the hair to look if I was using hair planes. It would be easy to retopolgize each "clump" of hair seperately by just extruding the edges of a plane out along the hair and just beyond the tips of the clump.
My question is... what comes next? I use xnormal to generate normals/base texture painting in zbrush/ao... and I'm wondering what you guys think the result of baking the highpoly hair clump to the planes would be.
Could I fill the hair strands with a flat white color in zbrush and then bake the base texture to the flat geometry? Would it provide me with a suitable alpha for the hair?
I've attached examples of the character. Please let me know what you think! Is this a crazy hair-brained idea? Or might it actually work? I'm at work or I'd give it a shot right now!
Thanks!!
Replies
Wait - what are you doing exactly ? The zbrush hair in these screenshots is looking very interesting!
Pior - the hair in zbrush is grouped clumps of individual strands, I just duplicated a single strand and used the move/move topo brush to group them into clumps/layers. I then used the pinch/smooth brushes on the tips. Here's a close up pic.
On the smaller images it looked like some sort of soft fur effect, but I get it now
So regarding your original question then : I think the best way would be to keep what you have at the moment on your highpoly (since it gives you a convincing target look to achieve) but go the very simple oldschool way for the ingame version - manually creating your transparent hair texture, applying it to strips, and so on. Then, using this technique, try to match your intended target look. I don't think you'll be able to take any shortcuts ...
I actually gave it a shot last night--painted the highpoly white and baked it to be used as an alpha. Baking it to the polystrip worked fine--I just made sure to run the ray tool in xnormal to get the correct ranges and it baked pretty much flawlessly.
The tips of each strand were a little too solid, but I can take the baked alpha texture into photoshop and break up the thicker solid strands... like Cryrid said, "feather" them out a bit. And then hand paint the diffuse.
But doing it this way definitely makes the building/placement of polystrip hair much easier for me and the ability to bake out a base for each one of the strips gives me something to work with. It should make the whole process of working on hair much easier (for me at least).