Because inquiring minds want to know.

Rusty

If you put them under the head... you couldn't use collision detection could you?

-vern

Nope. It seems to work great. Been doing it for a year or so. The only other people I know doing hair do it that way as well. Its too hard to put it 'above' and putting right on the head causes you to loose a lot of control. Here's someone else who does it that way:

http://www.dukegraphics.com/hairinfo.html

Rusty

Edit: By doing it this way you can switch the hair-do easily on your model and also make the hair-do transferable to other models. Go one more step and keep the hair-model (hair cap) but switch out the material (the hair system) and now you have the ability to make color independent from the hair-do (i.e. any 'do' with any color on any model). I explained how I do this and showed examples in another post a while back. In the AM library I have half a dozen hair-dos (model section) and about a dozen colors (material section) which I can mix and match on my character models.

Edit2: The emmiter mesh is placed very close to the head mesh (perhaps under the collision detection radius). The hair goes through it and collision detection works great. I've never had to worry to much about how close the mesh is but basically I copy the top of the head and shrink it a bit. BTW all my models use the same head mesh {Bill Youngs CD) and the tops of their heads are the same for male/female for the express purpose of transferring hair-dos around. Using the same mesh means you can flatten it the same way and also you can transfer face maps from model to model -- I have libraries of male/female face maps that can go on any of my models.

We only use hair for trees.

Sometimes we will apply it under the surface, and other times on the surface itself.

David

I put it under, just seems logical because it gives you total control over where the hair is.

Surely the third option is most logical. Of course, you would probably need to use an image to define the boundary of the hair.

At first glance, absolutely. But once you're into the details, things change (note I do realistic characters but the following is true for any complex character model).

If you've worked with hair... or perhaps I should say attempted to create female hair-dos of any complexity, you would see the advantage to using emitters which are not part of the character model. Sometimes you need independent patchs that can point in any direction as well as take hair systems with guide splines that have different numbers of CPs or other differing attributes. Also, concerning the upper eye lashs and, to a lessor degree, for eye brows ; animating the model mesh so it looks good is rarely in sync with animating the hair emitters so the hair continues to look good and point in the correct direction.

Back to head hair -- beyond any desire to keep 'dos' and hair color independent of models so you can switch hair-dos among models which is perhaps something only I might need -- modeling the character head is rarely in sync with the proper type of mesh needed to emit evenly spread, problem free hair. Hair density is tied to patch size so evenly proportioned patches are desirable. 3 and 5 point patches as well as hooks can sometimes do strange things with hair. Also keeping the emitter patches separate gives much more control over the hair line (and you still use decals to control this). Trying to accomodate all these things to any degree while spinning the mesh for a character head is usually impossible or, at the very least, a major headache -- you completely avoid all this by making the hair emitters separate.

IMHO of course. :-)

Rusty

Edit: I'm surprised that 40% use the head mesh.

I make a skullcap below the head mesh, and emit from that. It does give a lot of flexibility when grooming since you can get extra grooming guides for a hair "part" if you split the skullcap into sections.

All three are viable "hacks" to produce good head hair... I guess the most logical way may not be the most efficient way nor the most stylish way. I perfer the third option only because you don't have to add more mesh or paste it in. It takes a lot of forethought to make good hair in any case. It calls for a lot of patience also.
Aside from that... hair has everything needed to create a realistic hair look, in my opinion.

I'd like to see the Hash guys revisit hair in the future, and refine it a bit. The new hair shaders are cool, but collision-detection needs some attention. I'd like to see it work as well as the C-D in SimCloth...but then, I always seem to be making REALLY long female hair.

I have tended to use the 'over' the scalp method. As stated, it does not mess-up the possibility of collision detection, and when placed very close to the skull and set to transparent, it is not seen or noticed.


I agree that working with V11+ hair is very time consuming and much patience is needed.

I tried the over-the-scalp method, but the AO renderer seems to convert transparency maps to color maps, effectively turning my emitter patches into a hairy yarmulke.

Guess I'm suck with under-the-scalp for now...

When working on my guitar I learned the hard truth that AO doesn't work with transparency at all, and this is common across 3d software (i.e. not just an AM thing).

Anyway, I used to use the actual head patches for my hair but I've recently switched to using skull caps under the head for all the reasons listed above. It really gives you the most flexibility.

Can someone tell me the reason hair slips off my models head when animated and moves (the model that is ) is it my machine or card or have I missed something?.I have it on a skullcap under the skinn

You mean in real time display (not rendered to disk)? This happens to everyone I think -- you have to press the space bar to get the hair to redraw properly. In the real time viewer I never have hair turned on when I'm animating. Really slows things down.

Now if the hair is slipping off the head in a render to disk -- that's another story and not right.

Rusty

Have you remembered to attach the skullcap's CP's to the headbone?

ah John you got it no I never thought about that thank's, sheee what a wally Rusty thank's that not animating in realtime is a good idea ,it doese slow things right down thank's
sorry not done enough to vote