Trying to animate only y possition with an expression

[Mylenium]

Assuming you used the “Audio to Keyframes” keyframe assistant, this will work:

[position[0],thisComp.layer(“Audio Amplitude”).effect(“Left Channel”)(“Slider”)]

Mylenium

[Pour Myl

[Dan Ebberts]

If you just want to offset your y position with the audio amplitude, you probably want something like this:

multiplier = -5;
audio = thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”);
value + [0,audio*multiplier]

Adjust multiplier to set the direction (minus is up) and amplitude of movement.

Dan

[Nick Esposito]

Thanks for you answers, I did use convert audio to keyframes.

My problem is I can’t animate only the y position.
When I add the expression it effects both the x & y

How would I make the expression target only the y axis of movement?

Cheers!
Nick Espo

[Dan Ebberts]

Which expression are you talking about? Either of the ones suggested here should only affect y.

Dan

[Nick Esposito]

Thanks guys for your time!

I used this one:
[position[0],thisComp.layer(“Audio Amplitude”).effect(“Left Channel”)(“Slider”)]

For my own edification. How would I change this expression and make it effect the y axis?

Cheers!
Nick Espo

[Dan Ebberts]

That expression should move your layer to the top of the comp (without changing the x position) and bounce it downward in response to the audio (i.e. on the y axis only). Is that not what it does for you?

Dan

[Nick Esposito]

It works great. Thanks for saving the day. But why does it work?

Like in:
[position[0],thisComp.layer(“Audio Amplitude”).effect(“Left Channel”)(“Slider”)]

Is it [position[0] that isolates the y axis? How would I isolate the x axis?

Thanks!!!!

Cheers!
Nick Espo

[Dan Ebberts]

position[0] is the pre-expression x value (static value + effect of any keyframes). So this expression:

[position[0],thisComp.layer(“Audio Amplitude”).effect(“Left Channel”)(“Slider”)]

says – use the pre-expression x value for x and the audio amplitude for y. To keep the original y value and affect x only, you’d do it like this:

[thisComp.layer(“Audio Amplitude”).effect(“Left Channel”)(“Slider”),position[1]]

Dan

[Nick Esposito]

OK. I’ll try to understand that.
Thanks for the help!
It works great.

Cheers!
Nick Espo

[Steve Roberts]

The old long-form way of writing “position” may be instructive:

{position[0],position[1],position[2]]

… means “x position, y position, z position” for a 3D-enabled solid. If you write that (or just the two-dimensional version) then highlight “position[1]” and pickwhip to it, you’re in business.

There are other ways. Search the COW for “Ebberts” as author, and copy the posts to a word processor. Dan’s posts are worth saving, and he never wastes a post.