HI- V15.0i
Wondering if anyone has been down THIS road.

I have a character with hair that I have groomed while the hair was set at 'Constraint=100%'. Now, I want to make a pose-slider or find another way to make the 'hold' on that hairstyle let go...as in animate down to zero % constraint... and then back again to the groomed style. The pose slider AND animating the constraint value on the timeline in the choreography seem to have an 'all-or-nothing' effect, so the hair 'pops' from one setting to the next and back. I am looking for more of an incremental change.

Thanks for any speculation.

Make sure you set the channel interpolation, for the percent of the target constraint to, to something other than "hold".

I'm having a hard time finding just where that would be...

If the target constraint doesn't show a little icon to change the interpolation method for the percentage property, switch to channel view in the timeline, [ctrl-a] to select all the keyframes for the percentage, right-click inside the selection box and choose Curve > Interpolation > zero slope. Then double-click inside the selection box and in the dialog that pops up, set Interpolation to "Default". Hopefully that will help, but I have never tried to change hair styles in a pose...

Finally solved this one.
I achieved what I was after in an action. A made an action where the hair's stiffness property reduced from 100% to zero% in 30 frames. Then, in the choreography I keyframed the actions 'ease' amount to get the hair-style to loosen when I wanted it looser- and return when I wanted it back.

The result can be seen in my 'Betty' sample on her front 'bangs' as she shakes her head:
http://www.youtube.com/watch?v=97n_qtNRYhs

Thanks for your input Holmes and Mike!

That a great solution matt. I always forget about an Action's "Ease" property.

Hey matt, that link isn't going to your sample, it's going to Brand X.

Thanks Rob! Fixed it now.