Expression Cluster, Zero out 540 slider

[alexanderk38549755]

Like you can see, I have a null object where I have stored some sliders which is hooked/pickwhipped to some shape layers to be able to control the more easily. My problem is how to change the sliders value to 0 while keeping the actual (540) value. I want to make the position where they are now 0 and be able to drag it to make the shape layer go upwards.

Shape layer is connected to null slider and can only move on the y-axis with the expressions I have set up:

temp = thisComp.layer("Control").effect("Slider Control 2")("Slider");

[value[0], temp] 

If you were wondering.

Sorry if its confusing.

(Discussion successfully moved from The Lounge to After Effects)

[Dave_LaRonde]

You're right -- it IS confusing because it is a VERY strange way to work.  Why on Earth would you want to do that?

[alexanderk38549755]

I wanted it to be easier to change the different setting by having everything in one null. Changing 540 to 0 is to be able to see more clearly what the current value is.

It is meant to be a preset-ish kind of project.

Have any alteration proposes?

[Kyle Hamrick · Accepted solution]

[@Dave, probably because After Effects has the ability to easily condense control of many layers into one place, with modifiers, making working with complex setups infinitely easier. This is a pretty common practice.]

If I'm understanding your question correctly, you might just need to add a simple offset to your y value.
[value[0], temp-540]

If that doesn't get you where you're going, check out the linear function. It allows you to do things like having 1-100 on a slider correspond to 0-360 in rotation, for example, or... pretty much whatever else you might want. You can turn any number range into another number range, and they don't have to be the same type or "distance," as it were. It's kind of hard to explain in words; there's a good video tutorial here.

[alexanderk38549755]

Thanks! adding "+540" after the temp made it center with the slider at zero.

[P.M.B]

Yes, for some reason AE maps space with '0' or 'origin' being the upper-most left-hand corner of the composition. So what intuitively seems it should be '0' is actually the halfway point of both total width and height of the composition.