Expression syntax help

[Lloyd Alvarez]

Hey Eric,

You use parenthesis to group your calculations, so in your case it would go like this:

( thisComp.layer(“Rotating Lens Part”).transform.zRotation+88.7 ) * .81

and just to further explain it, if you wanted to the divide that result by 2+2 you would do it like this:

( ( thisComp.layer(“Rotating Lens Part”).transform.zRotation+88.7 ) * .81 ) / (2+2)

Hope that makes sense.. also there’s a forum for expressions.. you should find the link on the menu at the top of this page.

-Lloyd

https://aescripts.com

[Eric Goldstein]

Hi Lloyd,

That’s just what I needed. I had the front parenthesis in the
wrong place.

Thanks,

Eric

Eric Goldstein
Giraffe Film Company
Los Angeles
eric@giraffefilm.com

[Eric Goldstein]

Hi Lloyd or any other expression gurus out there,

I’m using this expression to move x and y positions based on
z rotation from another layer:

x =thisComp.layer(“Rotating Lens Part”).transform.zRotation;
[x+300.7, x+347.7, x]

The values added to x for x and y are offsets to place the layer in a particular position. I think I might be able to do this by adjusting the anchorpoint rather than doing this in the expression.

Anyway, I need to reverse the negative to positive rotation coming from the controling layer in the formula. How could I do this?

Thanks again,

Eric

Eric Goldstein
Giraffe Film Company
Los Angeles
eric@giraffefilm.com

[Eric Goldstein]

Hi Lloyd and others,

I figured out how to reverse the direction of the rotation using a negative sign. However, I now need to refer to a different comp. One of my expressions is:

(thisComp.layer(“Rotating Lens Part”).transform.zRotation+88.7)*.673

I assume I replace the “thisComp” with the name of the comp I want to use. So far I haven’t been able to get AE to take what I’ve tried.

Do I have to define the name of the Comp before referring to it? Or is there some syntax I’m not aware of? I tried using the name of the comp with and without parenthesis to replace “thisComp.” This didn’t work.

Any help would be great.

Thanks,

Eric

Eric Goldstein
Giraffe Film Company
Los Angeles
eric@giraffefilm.com

[Eric Goldstein]

Sorry, I feel like I’ve been having a conversation with myself. Anyway, I found the answer to my question.

(thisComp.layer(“Rotating Lens Part”).transform.zRotation+88.7)*.673

becomes:

(comp(“name”).layer(“Rotating Lens Part”).transform.zRotation+88.7)*.673

Thanks for the help,

Eric

Eric Goldstein
Giraffe Film Company
Los Angeles
eric@giraffefilm.com

[Darby Edelen]

I recommend you post in the After Effects Expressions forum in the future, you’ll probably find more help there with questions like these.

Also I recommend that you look into the linear() function as a potentially valuable resource to use in converting values instead of arbitrary multiplication. Sometimes your method is required, but usually the linear() function is much more elegant.

And since you’ve expressed an interest in expressions, check out this site:

https://www.motionscript.com/

Darby Edelen

NVIDIA
Santa Clara, CA