Link a keyframe to slider control without affecting other keyframes

[shaneg6443592]

I'm designing a lower third for one of our brands and have an animated object with 3 keyframes.

I need to link the 3rd keyframe to a slider so my team can eventually adjust that value in Premiere with essential graphics without affecting the other keyframes.

What expression should I use to do this?

I imagine it would look something like this (with better syntax):

if ( key(index) = 3 ) {

key(index).value = effect("Slider Control")("Slider");

}else

key(index).value = value

[acertik]

Has anyone figured out a solution for this? I'm doing the same thing, only I want to link a specific keyframe to a sourceRectAtTime() for the lower third text layer.

Thanks.

[angie_taylor]

Almost right. You'll need a Linear expression in there to convert values. Here's a solution that will allow you to control the KF between 0 and the slider value, courtesy of the brilliant Dan Ebberts;

if (numKeys > 1){

t1 = key(1).time;

t2 = key(2).time;

v1 = 0;

v2 = effect("Slider Control")("Slider");

linear(time,t1,t2,v1,v2);

}else value

[rubenvdheuv]

I like this expression,

But what can I do to link more than 2 keyframes to sliders?

Key1= slider1; key2=slider2; key3=slider3

etc.

[default872dsr0ryn3l]

I'm able to make this work with 2 keyframes but not with anymore than that.

What happens if you have an in and out movement and you want to control both? 

I've tried adding 

t3 = key(3). time;

t4 = key(4). time;

v3 = effect("Slider Control")("Slider");

linear(time,t1,t2,t3,t4,v1,v2,v3,v4);

v4 = effect("Slider Control")("Slider");

linear(time,t1,t2,t3,t4,v1,v2,v3,v4);

But it's not working.

For context; I need these keyframes to be controlled with a slider so that I can make the motion editable in Premiere Pro

Any help would be super appreciated.

Thanks

[Dan Ebberts]

Try replacing your last line with this:

if (time < t2)
  linear(time,t1,t2,v1,v2)
else if (time < t3)
  linear(time,t2,t3,v2,v3)
else
  linear(time,t3,t4,v3,v4)

[EALS]

yeah, it works

if(numKeys>1){

t1 = key(1).time;

t2 = key(2).time;

t3 = key(3).time;

t4 = key(4).time;

v1 = 0;

v2 = thisComp.layer("Comandos").effect("Comprimento")("Slider");

v3 = v2;

v4 = v1;

if (time < t2){

easeOut(time, t1, t2, v1, v2);

} else {

if(time < t3){

ease(time,t2, t3, v2, v3);

}else{

easeIn(time, t3, t4, v3, v4);

}

}

}else value

[Jon Beech]

Hi Angie,

I made good use of a version of this expression to control a slider when the first keyframe is used on a property of a layer located right at the start of the comp. I am aiming to control the 2nd keyframe on a property with a slider in my case.

if (numKeys > 1){

t1 = key(1).time;

v1 = effect("Y Scale Offset (last KF)")("Slider")*0.6;

linear(time,t1,v1);

}else value

However I would like to make use of an expression which works in the same way when the layer starts halfway along the timeline? Is this possible? Do I need to replace the "time" function with something else?

Thanks