i have an composition (Scene1). In this comp. there is an other comp. (Woman-Walkcycle) and in this comp. there is an comp. (mouth) with different states of her mouth in layers (normal/laughing/sad).
In "Scene1" the woman changes her position from right to left and the comp. "Woman-Walkcycle" loops.
For example on the 200 frame i want that the mouth goes from normal to sad. It would be nice if i can make an keyframe with an expression which tells the comp. mouth to change the layers-opacity or turn them on or off.
i use after effects for many years now but never used expression. hope you can help me.
and sorry for my bad english. Its not my first language.
If The the mouth "Fade Out" Part is not important, you can put the mouth expressions as layers in a comp, and every layer will be in a different second. (for example sad mouth in second 0 and smile mouth in second 1).
and with time remapping hold keyframes on the comp to pull out the mouth that you wish to see (the keframe with value of one will show the smile mouth).
It's not with expressions but it should be a good start!