this formula is about offsetting animation of several objects (or points, etc.) over a period of time, in such a way that the interval of time for each object is related to number of objects and the desired period of time.
Let's say you have 10 objects, and you want to animate all of them over 3 seconds, with some time offset for each object. With this formula you can change the number of objects, adjust the amount of offset or adjust the period of time, and each object will automatically adjust its start and end time, so all object animation will fit within the specified period of time.
Recently, I started learning Houdini and VEX. I was curious to see the application of this formula inside Houdini.
then I found this thread:
in the example of Twisting Box, matt uses "smooth" function.
this is what I was looking for: smooth() function in Houdini is the equivalent to ease() function in AfterEffects.