Text tracking with a sine shape

[demetriomancini]

Hi,

I’m looking for an expression that, applied to a text layer with a high tracking value (250 for example), will adjust che space between each couple of letters with a sinusoidal shape, with a zero value on left and right and the maximun value at the center. The width of the text box should be retained. It also would be nice to have a parameter to animate the “strength” like in the attached image, that is a simulation of the result I’m looking for.

Thanks in advance

[Dan Ebberts]

I'd start by adding a Tracking Animator, adding an Expression Selector, deleting the Range Selector and using an expression like this for the Expression Selector's Amount property:

tt = Math.max(textTotal-1,1);
a = (textIndex-1)/tt;
100*Math.sin(Math.PI*a)

Then adjust the Animator's Tracking Amount.

[demetriomancini]

Thank you Dan, but it doesn’t seem to work:

Error: ReferenceError: textTotal is not defined

[Dan Ebberts]

The expression has to go in the Amount property of the Expression Selector. Anywhere else and you will get that error message.

[demetriomancini]

That’s perfects, thanks again!

Is there a way to animate the strenght of the curve (which corresponds to the difference of spacing between the letters at the ends and the central ones) while mantaining the same width of the paragraph? Like on the image attached to the first post.

[Dan Ebberts · Accepted solution]

You could try adding a slider, and adjust it between 0 and 100, and change the expression to this:

s = effect("Slider Control")("Slider");
tt = Math.max(textTotal-1,1);
a = (textIndex-1)/tt;
v2 = 100*Math.sin(Math.PI*a);
v1 = 63.7;
linear(s,0,100,v1,v2);

[demetriomancini]

Great! That’s exactly what I was looking for.