How to auto calculate a number when a slider is in a certain range?

[Bram Hoekstra]

I'm curious if there's is a solution to the following:

var horizontal = comp("Render").layer("Controller").effect("B-films Credits Builder")("Horizontal Position");
var vertical = comp("Render").layer("Controller").effect("B-films Credits Builder")("Vertical Position");
var depth = comp("Render").layer("Controller").effect("B-films Credits Builder")("Depth Position");
[horizontal, 1920 - 420 - vertical, -depth];

The bold text has to be automatically calculated when the vertical slider is between 0 and 540.

If the vertical slider is at 540 it should be 420, when the vertical slider is at 0 it should be 0 and between those value it should calculate the value automatically.

Is there any way to do this?

[Mylenium]

If you know the values it's as imple as using a linear() interpolator to derive the inbetween values:

linear(vertical, 540,0,420,0);

Mylenium

[Bram Hoekstra]

It sorta works, it sorta doesn't.

I need the slider to keep it's original values.

I only need the offset between 1920 and the slider to be recalculated.

[Rick Gerard · Accepted solution]

You just need to declare some variables. Here's the code on a text layer and the resulting values:

vertical = effect("Slider 1")("Slider").value.toFixed(1);
vertical_Clamp = clamp(vertical, 0, 540).toFixed(1);
vertical_Ofst = linear(vertical_Clamp, 0, 540, 0, 420).toFixed(1);
// the following code displays the values for the variables
"Vertical Slider:  " + vertical  + "\r" + 
"Vertical Clamp: " + vertical_Clamp + "\r" +
"Vertical Offset: " + vertical_Ofst

Plug those variables into your expression and it should work. I added clamp(1) to the end of each variable to clean up the text display. You can delete it unless you want pixel-level rounding. 

[Bram Hoekstra]

Thank you very much!

This is exactly what I meant!