Trigger Time Remap with a Checkbox Control

[Andrei Popa]

Time in expressions is in seconds. I think it jumps to 40 second, not frame. However, that is not important. Try this and tell me if it works:

if (comp(“2.1a. Creator”).layer(“ICON_CTRL”).effect(“ICON_CTRL”)(“Checkbox”)== false) {
    0
} else {
    endT = framesToTime(40);
    linear(time,0,endT,0,endT);
}

if you want the animation to start at the inPoint of the composition, use this:

if (comp(“2.1a. Creator”).layer(“ICON_CTRL”).effect(“ICON_CTRL”)(“Checkbox”)== false) {
    0
} else {
    endT = framesToTime(40);
    linear(time,inPoint+0,inPoint+endT,0,endT);
}

[Paulius v Ruksa]

Hi Andrei, thank you for your reply!

The second expression is definitely closer, but it still doesn’t behave completely right, if it’s unchecked it’s at frame 0 if it is it animates from whatever frame I am on at that moment which doesn’t work as I always need it to animate from frame 0 and hold on 40.

I tried to change some of the numbers and experiment with it. For example if I change the bold number 0 to say 40 it does what I need it to do, but it does it really slowly. as you mentioned that time in expressions is in seconds, I tried to use 2, but that didn’t work either.

Any ideas what could be missing?

if (comp(“2.1a. Creator”).layer(“ICON_CTRL”).effect(“ICON_CTRL”)(“Checkbox”)== false) {
    0
} else {
    endT = framesToTime(40);
    linear(time,inPoint+0,inPoint+endT,0,endT);
}

Thanks!

[Robert Müller]

Hi, so you want to let the time remapping happen when you click (set a keyframe to change the value) the checkbox right? Then you might need to use a for loop like this:

Im not really good at those loop things so this is not a perfect solution – like when you switch from off to on multiple times or you have 0 keyframes on your checkbox – but maybe someone else can help as well? 🙂

c=comp(“2.1a. Creator”).layer(“ICON_CTRL”).effect(“ICON_CTRL”)(“Checkbox”));
for(i=1;i<=c.numKeys;i++){
if (c.key(i).value== false) {
    0
} else {
    endT = framesToTime(40);
    linear(time,c.key(i).time,c.key(i).time+endT,0,endT);
};
}

[Paulius v Ruksa]

Thanks a lot for your help, Robert!

I still couldn’t get it to work, but I had another look at older threads and found this one:

https://creativecow.net/forums/thread/trigger-a-animation-using-a-checkbox/

One of Dan’s expressions work perfectly for my case. I have tried it before but must have made a mistake, now I applied it to my comp again and it works as it should. It’s this one here by Dan Ebberts (applied to my comp):

<pre class=””>

n = 0;

p = comp(“2.1a. Creator”).layer(“ICON_CTRL”).effect(“ICON_CTRL”)(“Checkbox”);

if (p.numKeys > 0){

n = p.nearestKey(time).index;

if (p.key(n).time > time) n–;

}

if (n > 0 && p.key(n).value)

time – p.key(n).time

else

0

Having said that, I have another question someone might be able to help me figure out?

In my main comp, I have a few components with videos. As I’m animating a scroll, the videos need to start playing. So In the Precomp I have a still layer and the video layer. I’m using a simple expression like this applied to Opacity:

if (comp("2.1a. Creator").layer("VIDEO_CTRL").effect("VIDEO_3")("Checkbox")== true) {100} else {0}

I’m simply showing the video on top of the still while the checkbox is on. The client however wants me to play sound with the video so I added a Slider Control to Levels and using the same checkbox to control the volume like this:

if (effect("VIDEO_3")("Checkbox")== true) {0} else {-100}

I was wondering if there’s any way to fade in the audio say in 20 or so frames rather than cut to it? So I want to use the same keyframe to start previewing the video as well as fade in its audio.

Thanks!

Trigger a animation using a checkbox

[Dan Ebberts]

Something like this maybe:

n = 0;
cb = effect("VIDEO_3")("Checkbox");
if (cb.numKeys > 0){
  n = cb.nearestKey(time).index;
  if (time < cb.key(n).time) n--;
}
if (n > 0){
  cb.value ? linear(time, cb.key(n).time, cb.key(n).time + framesToTime(20),-100,0) : -100;
}else{
  cb.value ? 0 : -100;
}

[Paulius v Ruksa]

This works great!

It will save me so much time and so many keyframes, this is exactly what I needed.

Thanks a lot Dan!