Open After Effects, go to File → Scripts → Run Script File…, select the script (2dnMotion.jsx), and the Secondary Motion panel will open.
Select one or more layers in your composition.
Check which transform properties you want affected. (Pos., Rot., Scale)
Adjust Amplitude, Frequency, and Decay as desired.
Click Apply to Selected (or Apply to Full Comp for all layers).
Preview your animation — tweak values until the bounce feels right.
If needed, click Delete Expression to remove it.
Amplitude – controls how strong the bounce is (higher = bigger overshoot). Frequency – controls how fast it oscillates (higher = quicker bounces). Decay – controls how quickly it settles (higher = stops sooner)
Position examples
Rotation examples
Scale example