I have spent some time trying to research the best way to create anime hair in 3D, and I am finding that there is not just one answer.  In fact, in Carrara, there is not an answer that I like.  Let me explain:

There are at least three ways to make 3D anime hair:

• Hair Siimulation
• Modeled Hair with Soft Body Physics
• Modeled Hair with Rigging and Rag Doll Physics
• Modeled Hair with Rigging and/or Morphs

All three of the other options start with modeling hair, which can produce a nearly perfect anime appearance, although that is a trick in and of itself.  I'm not going to analyze the sort of model structure that works best right now.  I'm more concerned with how I'm going to animate it later.

The first of the remaining options is modeled hair with soft body physics.  I actually think that this is the best way to do cel shaded anime hair in 3D.  This way you can construct a model that will render like the clumpy 2D hair that we are used to seeing, but you can still do a physics simulation to get the hair to respond in a realistic way without having to painstakingly animate it.  Now, its true that you can't beat key frame animation for overall effect in character animation, but we are not talking about moving arms or making facial expressions here.  We are talking about hair blowing in the wind or swinging after a movement of the head.  There is not really a need to key frame something like that if you don't have to.  It really should just follow the laws of physics.  Carrara, however, only has soft body physics in BETA form in Carrara 8, and its too buggy to be used in this way.

Since Carrara does not have a usable soft body physics, the last type of physics simulation that could help with the situation would be rag doll physics.  If the hair was rigged, then rag doll physics would allow the hair's rigging to be affected by gravity and other forces in the scene.  This would be pretty good too, but this is something that Carrara does not have at all.

This only leaves one method available.  Since I can't use physics, I have to key frame animate the hair.  I can do that by rigging the hair model, by assigning convenient morph targets, or both.  Rigging seems to be most desirable for basic motion.  Simple rigging too, so you can animate the motion of the hair as easily as possible.  Morph targets would add something very useful, though.  You can probably achieve some deformation of the shape with morph targets that you could not with rigging alone.  Also, a morph target might help with a complex movement like blowing in the wind.  Two or three morph targets to preset the key frames for that common scenario might help a lot.

In this way, Carrara has an annoying weakness that applies directly to what I do.  It is enough to make me think about other software again.  I love Carrara, especially the rendering engine, but it would be nice to take advantage of Poser's well developed cloth simulation or rag doll physics plug-in.  I suppose if I forked out a small fortune for Maya or 3D Studio, then they would also have a physics simulation that would work for me, or maybe something better that I am not even aware of.  I have tried simulating cloth in Poser and exporting it to Carrara, but I don't know a way to make that work.  If I could not make that work, then I am stuck choosing between Carrara's rendering or Poser's cloth simulation.

On the other hand, though, key framing the hair is not so bad.  After all, it does give you the most control, and it is the way traditional anime has been doing it forever.  Maybe that is just the way to go.  For now, that looks like the way I am headed with the hair I am planning.  I will rig it in Poser, though.  There is no sense in rigging stuff in Carrara when Poser rigs are compatible with Carrara and anything that supports the Poser content library.