When acceleration or deceleration isn’t smooth, movement appears mechanical. Abrupt changes in speed or direction are jarring and draw attention.
Avoid linear motion.
Entrances and exits
Changes in an object’s speed and direction draw user attention.
An object’s change in speed as it enters or exits the frame suggests the distance it is traveling. For example, slowing down while exiting draws attention and implies the object will stop near the frame edge.
During transitions in particular, consider what portion of the entrance or exit should receive the most attention.