Time remap expression and slider

[Miguel De mendoza]

Is a little confusing what you are trying to achieve for me, but I can tell you that you cant’t change the duration of any composition by expression, for that you need to use a script.

[Adam Greenberg] “The time remap expression will alter the speed from 10;00;00;25 to 10:00:03:11 ) and that is exactly what I want.

The other part of the math I am having a hell of a time with; is that this slider will have a decimal point. So let us say that the user enters 7.17 as the input value into the slider.

I want this to represent 7 seconds and 17 frames which logically would give me a time code of 10;00;07;16 ) because the comp starts at 10;00;00;00;00”

A simplest way to achieve that is to converting the input value to string and then split the string:

sliderVal = thisComp.layer("sliderLayer").effect("Slider Control")("Slider").value;
stringVal = sliderVal.toString();
timeFrames = stringVal.split(".");

At that point you only need to map the frame value (timeFrames[1]) to your framerate.

[Adam Greenberg]

Well I do not need to change the duration of this main output composition. The composition is set to lets say 10 seconds for example, but the precomp ( which is 5:10 ) in this comp has time remap enabled.

For now, manually I have 4 key frames and the person who edits this composition to the desired duration must move the 3rd and 4th keyframe together to the time they desire, for example 7 seconds and 10 frames.

But I know I can achieve this with an expression. manually moving keyframes leaves room for human error.

The best way to visualize this, is think if a logo that animates in a certain way in 25 frames, slowly zooms in until it animates out at the end in 57 frames.

Well in order to make this logo shorter or longer, you would need 4 keyframes in a remap.

The first 2 remain fixed in time so that you do not change the speed in which it animates it. the 3rd and fourth need to be moved together in order to respect the speed of the animation out.

Of coarse the speed of the middle is what changes.

I know i can can create 4 variables so that variable 1 and 2 never change. variable 4 would be the main formula I am looking for which also converts my slider to frames, then variable 3 would be variable 4 minus 57 frames. Then the template would be driven by this main expression linked to the slider.

[Dan Ebberts]

assuming your slider is on a layer named “controls”, it might look like this:


if (numKeys == 4){
s = thisComp.layer("controls").effect("Slider Control")("Slider");
d = key(4).time - key(3).time;
if (time < key(2).time){
value;
}else if (time < s-d){
linear(time,key(2).time,s-d,key(2).value,key(3).value);
}else{
linear(time,s-d,s,key(3).value,key(4).value);
}
}else
value


Dan

[Adam Greenberg]

Thanks Dan, I think you are on to something, however, it is not giving me the expected result. And I believe that is due to my explanation.

the 3rd keyframe should always be the 4th keyframe minus a fixed value.
this fixed value is 57 frames.

so that the animation between those 2 keyframes never changes.

For example, right now, if I enter 6 in your slider,

the 4th keyframe becomes 00;00;04:18
and the 3rd becomes 00;00;04:01

What should happen is the 4th should be 00;00;06;00

and the third should be ( 6:00 – 57 frames ) – so 00;00;04:03

if i add 8.22 in the slider

I would like to see the following

keyframe 4 = 00;00;08;22
keyframe 3 = 00;00;06;25

if someone enters 3.15 in the slider

keyframe 4 should be 00;00;03;15
keyframe 3 should be 00;00;01;18

FYI – the original 4th key frame is at 00;00;05:09
and the 3rd is at 00;00;03;12

In all instances,
key frame 1 should be 00;00;00;01
keyframe 2 should be 00;00;00;25

This is a 29.97 comp by the way.

Thank you.

[Dan Ebberts]

Like this then:


if (numKeys == 4){
s = thisComp.layer("controls").effect("Slider Control")("Slider");
d = key(4).value - key(3).value;
if (time < key(2).time){
value;
}else if (time < key(3).time){
linear(time,key(2).time,key(3).time,key(2).value,s);
}else{
linear(time,key(3).time,key(4).time,s,s+d);
}
}else
value


Dan

[Adam Greenberg]

Hi Dan, I have been studying the expression to understand why its not behaving as expected. But to keep things short, when I increase the slider, the key frame value ( of keyframe 3 and 4 ) goes down. For anyone who is interested in this advanced control I am looking for, here is something very very close I found on the web, but I can not adapt it to my needs.
Enjoy ( youtube link and expression below )

For this template I had no choice but to accept the fact that I can not achieve what I want, but I know its possible. Thanks again for your help. As my template is, there is only one step more in my procedure, so no big deal.

https://www.youtube.com/watch?v=sWw4E_gLXlI

var fps = 1/ thisComp.frameDuration;

//sliders values
var lt = comp(“controls”).layer(“controls”).effect(“logo-total”)(1)*fps;
var li = comp(“controls”).layer(“controls”).effect(“logo-in”)(1)*fps;
var lo = comp(“controls”).layer(“controls”).effect(“logo-out”)(1)*fps;

var m1 = 0;
var m2 = framesToTime(li);
var m3 = framesToTime(lt – lo);
var m4 = framesToTime(lt);

//keyframes in your original composition
//change these numbers depending on the key moments of your composition
var k1 = 0;
var k2 = framesToTime(50);
var k3 = framesToTime (87);
var k4 = framesToTime(112);

if (time < m2) {
linear (time, m1, m2, k1, k2);
} else if (time < m3) {
linear (time, m2, m3, k2, k2);
} else {
linear (time, m3, m4, k3, k4);
}

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