Hi,
I'm using the expression below on a few layers in order to achieve a 'rolodex' look. The expression was applied to the x axis of the layers.
numCards=thisComp.layer("Null 1").effect("numCards")("Slider");
viewCard=thisComp.layer("Null 1").effect("viewCard")("Slider");
v=((index-1) * (360/numCards) + viewCard*(360/numCards))%360;
if (v<10) {
ease(v,0,10,-20,120);
} else {
linear(v,10,360,120,340);
}
Just copy&paste the expression, then substitute the values in the ease() and linear() functions to fall within sensible ranges for opacity. The code is pretty unsafe and unelegant, though. if I were to do it, I'd create completely different one...
Mylenium