Follow-through means secondary parts of an object continue moving after the main body stops

Follow-through and overlapping action is the principle that when a character or object stops, not all parts stop simultaneously: the main mass stops first, then secondary elements (hair, clothing, tails, dangling jewelry) continue moving briefly before settling. This staged stopping — different parts arriving at rest at different times — reads as physically plausible because it reflects inertia: lighter, more flexible parts have less momentum and are affected later. In generative design, this principle applies when animating compound objects: the primary position snaps to a target, while secondary elements are on slower lerp values that ‘chase’ the primary. Without this, all parts arrive simultaneously, making the object feel rigid and toy-like.

Examples

A character with a ponytail: when they stop running, the body stops, but the ponytail continues swinging for a beat. In code: primary position lerp(primary, target, 0.2), secondary lerp(secondary, primary, 0.1) — secondary lags behind.

Assessment

Explain what follow-through means and why it makes motion feel physical. Then describe a code strategy for making a secondary element lag behind a primary one using lerp.