How to obtain an expression later in time

[Mike Clasby]

This little expression from Dan should work:

delay = 10; //number of frames to delay

d = delay*thisComp.frameDuration*(index – 1);
thisComp.layer(1).opacity.valueAtTime(time – d)

It came from here:

https://www.motionscript.com/mastering-expressions/follow-the-leader.html

witch is part of his main site, sort of the online Holy Grail of Expressions:

https://www.motionscript.com/

[Lucia Bastenhof]

Thanks yikesmikes, I was just looking what I could do with valueAtTime ! 🙂 . I pasted your expression (changing opacity to scale too), but it doesn’t work exactly : the layer appears in fact exactly 2 seconds after the animated layer :
(with 25 fps 🙂
the animated layer appears at 03:18
the linked layer appears at 05:18
10 frames later, that would be 04:03.

But the solution is not very far ! 🙂
I’m searching further. I’ll go to motionscript too. If you have an idea about what’s the wrong piece, it would be great !! 🙂

Thanks !

[Dan Ebberts]

It sounds like your linked layer is layer 6. That would give it a delay of 50 frames. For a 10 frame delay, the expression assumes that it would be layer 2. There are, of course, ways to solve the problem – it just depends on what you’re trying to do.

Dan

[Lucia Bastenhof]

IT IS the layer 6 !!! 🙂
I think I begin to understand something… My brain is working, but I think it would work better with your help 🙂
So, I’ll try to be more accurate :

I try to animate 8 letters (il ou elle).(they’re normal layers).
I want to give the feeling that each letter appears like a drop on water.
I don’t have any recipe. I made a first animation on the first letter, and it seems to be a good direction, but I’m sure I’ll have to make changes later.

There are 3 layers per letter : beneath the first one (only disappearing after a while), the same letter appears 2 times, like circles on water (mmh…not exactly yet… :-). Those 2 samples are more transparent and are disappearing, they are bigger, and while disappearing, they become always bigger. The colour is changing too, becoming more white.

What I did on the first letter, after the duplication :
– On the first layer (say letter 1-a) : animation of Transparency
– On the second layer (letter 1-b) : 10 frames later, animation of Levels-histogram, of Scale, and of Transparency.
– On the third layer (letter 1-c) : the same 3 animations, 10 frames more later.
(These 3 layers have the same entry point. To avoid any mistake during my search, I put a keyframe at the entry on each animation.)

So, I’d like to obtain the same animation for all the letters ! 🙂
I think each letter should appear 10 (or less…) frames after the previous one.
So, I began to try something like that :
1- Letter 1-a
2- Letter 1-b
3- Letter 1-c
4- Letter 2-a, Transp. linked to Transp. of 1-a
5- Letter 2-b, each animation (Levels, Scale, Transp.) linked to the same one on 1-b
6- Letter 2-c, linked to 1-c
7- Letter 3-a, linked to 1-a
8- Letter 3-b, linked to 1-b
9- Letter 3-c, linked to 1-c…

8*3—> I have 24 layers.
All the *-a are linked to 1-a, each time 10 frames later.
All the *-b are linked to 1-b and the *-c to 1-c on the same way.
(Maybe it’s better to gather the a, the b the c together, but I think it’s a detail)

I think you understand all the interest of an expression in that case ! 🙂
I would have to link each layer separately, to change the valueAtTime or the number of frames, but then I could easily make changes (on the animations).

I hope you read me so far ! 🙂 and I hope you have an idea about the solution.

Thanks ! 🙂

[Dan Ebberts]

Try this variation:

delay = 10; //number of frames to delay

idx = index%3;
d = delay*thisComp.frameDuration*(idx – 1);
thisComp.layer(1).opacity.valueAtTime(time – d)

Dan

[Lucia Bastenhof]

Thanks Dan ! 🙂

It must be the right expression ! I pasted it on Opacity and Scale, on layers 5 & 6 (letter 2, b and c). (changing only opacity to scale and the number of Comp.layer)

5- Letter 2-b : it works perfectly ! :-). The letter appears 10 frames later.
6- Letter 2-c : The letter appeared 10 frames before the source layer (1-c).
I tried to adapt the expression, changing (idx – 1) to (idx), then to (idx + 1).
With (idx + 1), the letter appears at the right moment ! 🙂

So, I think you found the right expression ! 🙂 I just have to adapt it.
To adapt it, could you explain me some terms of the expression ? I did a first adaptation, at random, but I don’t understand exactly what I did…

I go on testing…

Thanks ! 🙂

[Dan Ebberts]

Sorry – I messed it up. That’s what I get for postiing without testing. This should be better and shouldn’t need any adapting (if I’ve understood your requirements).

delay = 10; //number of frames to delay

idx = Math.floor((index-1)/3);
d = delay*thisComp.frameDuration*(idx);
thisComp.layer(1).opacity.valueAtTime(time – d)

Dan

[Lucia Bastenhof]

Thanks Dan ! 🙂 It works perfectly ! 🙂

(Sorry for this delay, I was too tired those last evenings to go working on AE…)

It works exactly as I wanted, except for the levels, which seem to accept no expressions (or did I miss anything ?)

I think I will be able now to make the animation easily. But if you could, I’d like you to explain some keys of the expression. I suppose I just have to change 10 to another number to change the number of frames to delay. And what is the meaning of (index-1)/3) ? I’d like to understand… 🙂

Great thanks !! 🙂

[Dan Ebberts]

I’m not sure what levels you’re talking about. Sorry if I missed a key point.

You are correct, you would just change the 10 to change the delay.

Math.floor((index – 1)/3)

just groups the layers into groups of 3. The result will be that layers 1 through 3 will be in group 0, layers 4 through 6 will be in group 1, etc. The expression then uses that value to calculate the delay for each layer (the delay for layers 0 through 3 will be zero, for layers 4 through 6 it will be 10 frames, etc.)

Dan

[Lucia Bastenhof]

Thanks Dan for all these explanations ! 🙂

The levels I spoke about is the histogram. To animate the colour of the first letter, I animated the black entry (which is beneath the histogram). This black entry can’t be animated directly : I have to animate the “watch” of all the histogram, but this watch seems to be unable to support the expressions… Alt+Click on the watch has no effect.

Thanks ! 🙂