The expression is telling After Effects to wiggle the Position property 5 times a second with value between -25 and 25 pixels. Wiggle takes on the dimensions of the property it's applied to, so in our case it is wiggling both x and y (independently). If we only want y to wiggle, we have to change our expression a little. The Easy Expression to add to Position, for wiggle in X axis only (the red axis above) is: x = transform.position 0; y = transform.position 1; w = wiggle (2,100); w 0,y; In the example expression above, 2 is the amount on wiggles per second, 100 is the maximum wiggle value in the X axis. Here are some alternative, tried and tested.
Linear blends ' from ' and ' to ' and returns a new value. Exactly how much it blends between the two is dictated by 'progress'. In the following interactive example, linear is applied to a position property. You can see how the result is a point between the 'from' point and the 'start' point. Linear is an interpolation method. The expression lets you represent values in a variety of different ways, which Jake says “is key to making custom controls” in After Effects. Bartlett explains the structure and functionality of the expression and walks through a couple of examples showing how it can work. Ukramedia’s Sergei Prokhnevskiy.
Linear, in it's most basic form, takes 3 arguments and looks like this: linear(progress, from, to) ;
progress = a number between 0 to 1 determines how much to blend the values 'from' and 'to'.
from - blend from this point (or number, or color, etc...)
to - blend to this point (or number, or color, etc...)
Linear blends 'from' and 'to' and returns a new value. Exactly how much it blends between the two is dictated by 'progress'.
In the following interactive example, linear is applied to a position property. You can see how the result is a point between the 'from' point and the 'start' point. Exactly where is determined by the 'progress'.
After Effects Expression Linear Position Diagram
