Every visual animation is a parameter driven by a function of time — the character of motion is entirely in that function

All animation reduces to: parameter = f(time). What changes is not which parameter to drive, but how — the shape of f. Linear f gives constant-rate, mechanical motion. Eased f (ease-in: accelerate; ease-out: settle; smoothstep) upgrades from ‘computery’ to ‘designed’. Periodic f (sine/triangle LFO) sways a value between bounds — the workhorse for breathing and pulsing. Noise-driven f gives organic, non-repeating wander that resists mechanical loops. This framing makes motion design a single question: what function should govern this parameter over time? Understanding the four function families (linear, eased, periodic, noise-driven) covers the vast majority of visual animation decisions.

Examples

Rotation speed driven by sin(time) → periodic spin. Same parameter driven by smoothstep(...) → eased stop. Driven by fbm(time*0.1) → noise-drifting angle.

Assessment

Given a visual parameter (e.g. zoom level), describe what motion character each function family (linear, eased, periodic, noise-driven) would produce. Then name which family you would use to make it feel ‘alive’ vs ‘mechanical’.