Is there a way in the current SVN to comb say, 100 hairs in the view port and have 1000 interpolated hairs appear in the render? I can’t seem to work that out.
Thanks
Glenn
in the “Visualization” panel, I believe that the “Disp” slider will help you, just look at the tooltip 
use child particles.
Like papulizer said…
You comb the 100 main (called “parent”) particles. Then, you choose either “Particle” or “Face” from the dropdown menu in the particle Children panel.
It seems that the children particles interp between the main (guide?) hairs okay except for their length. This plane has hairs grown from verts only with children hairs spawned between. You can clearly see the steppyness across the top as each child hair takes the length of a single guide only. The result is similar whether Vparents is set high or low.
Any thoughts?
Glenn
Just select faces instead off particles as shown in this screen grab. The plain has only ten particles, as you can see it smoothly interpolates between.
Thanks for the response.
My example did have faces selected. The difference between our approaches seems to be that I was spawning hairs from verts and not from faces in the first place. I need a hair per vert for what I am testing here so can’t emit randomly from faces. Using verts as the emitter yeids results like my example above where faces creates a blend like yours.
Glenn
Heres another screen grab. Nine parent particles, emitting from nine verts, with faces selected as the children type.
Are you using the latest SVN build? maybe you could try sending a .blend file and I’ll see if I can find the problem.
Heres a .blend of whats in the screen shot.
Great thanks. I completely worked it out last night as I was about to drop off to sleep. It was my fault as I had more then one guide hair per vert so it was interpolating between hairs at the same location. 
I’m an idiot!
Glenn
Your welcome