Animations in Blender always work in a linear direction, where you

define a Start and End frames for them. During playback, the animation

begins and ends based on those two frames. However, using a special

feature of the Graph Editor, it is possible to make any motion to loop

forever or with a defined number of repetitions.

To make an animation loop, you must create the motion first and prepare

it to use a loop. For instance, if you want to make an object go back and

forward forever, you should work in a way that your last frame uses the

same property location value as the first frame.

That way, your motion always ends at the starting point. Ready to begin

again!

An excellent way to make animations that shares the first and last

positions with the same property values is to add all keyframes before

applying any motion. In Figure 8.4, we have an object that we can

animate by making it scale up and down.