Creates a transition from one text to another one by replacing the first text letter by letter with the second text. This iExpression is applied to the source text property of a text layer. Create for each text a keyframe and the iExpression computes automatically the transition between the keyframes. If some text should remain unchanged for some time, simply create two keyframes with the same text at the beginning and end of this region.
the order in which the letters are replaced.
if the old and new text have different length, you determine here, how they are layed on top of another.
For each number, the random generator produces different results. If you have chosen "random" for Direction, you can try different numbers here to get different random directions.
Change for each Layer
With this option you get a different random values for each layer, if you apply the iExpression to several layers simultaneously