http://www.maxon.de/pages/products/c4d/modules/hair/movie_symmetrycut.html
chheck it ! Awesome…
yea that is pretty nice 
BTW i realizes that it is your 1111 post
nice number 
the dynamics are great!
curious when that will make it into blender.
Couldn’t it be done by creating a particle system, and than converting it to a mesh? You could set a number, in which the strands should be divided for the mesh.
Than, apply some softbody stuff to it, voila!
(I guess, haven’t done much with SB yet)
Softbody is already working on curves. The only problem is to have such cut possibility for curves.
[!]
it didn’t look to me like the strands were cut or cutout - they were shortened and deformed by the objects intersecting them - they also had a scale function (which I suppose could be a shortcut to our normal life button) then then enabled the actual static particles which produced the hair - how the hair was so “soft” and “flowing” i’m not sure - other than curves and force fields but that is cool! If we could just use objects (like we do with boolean operations) to deform the directions of the hair strands (and their life spands) we could produce similiar results! 
but how long would it take?
It shouldn’t be too hard to do because I think you can set relative hair length according to vertex group weights. So all you’d have to do is write a tool that sets the weight of the vertex based on the distance the intersection of the tool and hair is from the surface. The knife tool could possibly be modified to do that.