It depends on how you want to interpolate. As the relation may not be necessarily linear, there could be infinitely many ways in which the interpolation can happen.
Take a look at my drawing <http://imgur.com/bM8Gx2H> to see what I mean. I suggest an fcurve into the expression will be of great use as you can completely control the interpolation. It seems that either ICE or link with parameters are a better choice. However, if you want to use expressions, it is simply a condition of selecting one of the two equations straight line: Here is the expression that you can use on Eyefix: *cond( Slider <= 0.2, Slider / 0.2, ( 1 - Slider ) / 0.8 )* This expression will properly interpolate and even extrapolate( for value of slider outside the interval (0, 1)) Please note that the expression is in condensed form based on the values you provided : (0,0), (0.2, 1.0), (0, 1.0). If you change your point of choice from 0.2 to some other value then this expression needs to be changed. I have not included the method to derive this expression for the reason of being succint but it simply is an implementation of two equations of straight lines through two points plugged into a condition statement. Good luck! Alok. On Mon, Jan 27, 2014 at 12:20 PM, Emilio Hernandez <emi...@e-roja.com>wrote: > Yeah. ICE, ICE, Baby. > > > > > 2014-01-27 Matt Morris <matt...@gmail.com> > > I'd go the ice route as well, not least because you can add an fcurve node >> to control the amount of influence over the 0 - 1 range, so its a link with >> but without the keys or curves appearing in the character's dopesheet/ae. >> >> >> On 27 January 2014 16:56, Will Sharkey <willjshar...@gmail.com> wrote: >> >>> great stuff, I'll try both but I might just go down the ICE route. >>> >>> Thanks again. >>> >>> >>> On Mon, Jan 27, 2014 at 4:19 PM, Emilio Hernandez <emi...@e-roja.com>wrote: >>> >>>> It will work faster in ICE with the described method as you bypass the >>>> shape manager, or the animaton mixer. And go direct to the cluster to grab >>>> the point data as you are direclty adding the point positions. You can >>>> also drive the point positions with a weightmap as well, multiplying the >>>> output value by the weightmap, before setting the point positions again on >>>> itself. And it's easy to debug than getting, as Sergio said an expression >>>> to interpolate the weight of the shape. >>>> >>>> Cheers! >>>> >>>> >>>> >>>> >>>> 2014-01-27 Will Sharkey <willjshar...@gmail.com> >>>> >>>> Yeah, I would need the values interpolated. I could do it in ICE but I >>>>> thought it would be nice to keep it as a simple expression. >>>>> >>>>> Thanks for the help. >>>>> >>>>> >>>>> On Mon, Jan 27, 2014 at 3:47 PM, Emilio Hernandez >>>>> <emi...@e-roja.com>wrote: >>>>> >>>>>> Yes you can do it with expressions. >>>>>> >>>>>> It is a nested conditional. cond >>>>>> (slider=0,eyefix=0,cond(slider=.2,eyefix=1,cond(slider=1,eyefix=0,0))). >>>>>> But I wouldn't suggest this approach. There is an easiest way to do it >>>>>> in >>>>>> ICE. >>>>>> >>>>>> https://vimeo.com/84282621 >>>>>> >>>>>> >>>>> >>>> >>> >> >> >> -- >> www.matinai.com >> > > --
