Anton is right...what he describes as "volumetric" is a new way to design hair( been playin' with the same idea myself as you can see from this WIP ;-) ). It keeps the poly's managable and allows modellers to consider entirely new designs(like curly or really wavy hair) that will not choke systems. This is my experiment with the "volumetric" idea. The trans map is not as developed as Anton's yet, but you can easily see that newer, more realistic curly and wavey styles are now just around the corner. (when completed this will be a super long, conforming style)