---
title: Motion that reads premium
description: "Seven motion-grammar rules from frame-by-frame study of professional work — nothing stops, the camera acts, action overlaps, imperfection stays reproducible."
---

By now you can specify a frame precisely — exact copy, exact colors, exact layout, exact timing. This level makes it feel alive. Static frames can be perfect and the video still feels cheap if the motion is dead. Professional motion design follows a grammar you can put directly in prompts:

1. **Nothing ever fully stops.** Every "hold" carries ambient idle motion — a 1-2% breathing scale, slow drift, a shimmer. Never write "holds motionless"; write "settles into a gentle ambient idle." A frozen final second is the single biggest cheap-motion tell.
2. **The camera is an actor.** Give each scene one continuous camera move — a 4-8% push-in, a slow orbit, parallax between layered planes — easing gently but never settling on screen (compute the ease over a window slightly longer than the render).
3. **Overlapping action.** No two elements share a start or end time. Entrances stagger at irregular offsets; the next element begins while the last is still settling.
4. **Overshoot and follow-through.** Every pop scales past its target and settles back; letters can tumble in individually with rotation.
5. **Depth planes.** One or two large, heavily-blurred foreground elements drifting near the lens sell depth instantly.
6. **Match pacing to genre.** Showreel-style cuts run 1.5-4 seconds per idea; a stretched 8-second version of a 2-second idea feels slow no matter how it's animated.
7. **Handmade imperfection stays reproducible.** A stop-motion or hand-animated feel wants irregular timing, not machine-smooth eases — but true unseeded randomness breaks the render: HyperFrames must produce the identical frame every time it seeks to the same point, and `Math.random()` can't promise that. Seed a PRNG once at composition start instead, and step discrete elements between held positions (a "two-frame hold": land, hold two frames, jump to the next offset) rather than tweening continuously between them. The irregularity is real — it just comes from a seed, not from chance.

## The grammar, measured

The same composition built twice — identical content, identical layout; the only variable is the motion treatment. The first build commits the anti-patterns above: simultaneous identical entrances, no camera, a frozen final 2.4 seconds. The second applies the six rules.

<video controls muted loop playsinline preload="metadata" src="https://static.heygen.ai/hyperframes-oss/docs/images/prompting/motion-before.mp4" style={{ borderRadius: "0.5rem", marginTop: "0.75rem" }}></video>
*Every anti-pattern: tiles enter together, nothing overlaps, the last seconds are a freeze-frame.*

<video controls muted loop playsinline preload="metadata" src="https://static.heygen.ai/hyperframes-oss/docs/images/prompting/motion-after.mp4" style={{ borderRadius: "0.5rem", marginTop: "0.75rem" }}></video>
*The six rules: staggered overshoot entrances, a continuous 5% push, ambient idle, a blurred foreground plane, sparkline draw-ins as secondary motion.*

The difference is measurable, not just visible: in the final second the frozen build has bit-identical consecutive frames, while the motion-grammar build changes every single frame — corroborated by the encoder (211KB vs 2.5MB for the same content). A frozen final second is the cheap-motion tell you can test for.

## Handmade, still deterministic

Rule 1's ambient idle is *continuous* — a slow, smooth breathing scale. Rule 7 is a different tool for a different job: when the brief wants something that reads as physically hand-animated (paper cutouts, stop-motion, a wobbly hand-drawn line), continuous easing is the wrong texture — it reads as digital no matter how organic the curve. What you want is irregular, but reproducible:

> A paper-cutout garden scene: flowers, leaves, and a bee drifting on visible wires, like stop-motion. Seed a random offset per element at the start (same seed every render) so each leaf sways to a slightly different rhythm, but hold each position for exactly two frames before stepping to the next — discrete jumps, not a smooth tween. It should read as intentionally handmade, not glitchy.

Name the seed and the hold length explicitly — "seeded" and "two-frame hold" are the two words that keep an agent from reaching for `Math.random()` and quietly breaking every re-render. Ask for it, and seeking to frame 214 twice gives you the identical frame twice, exactly like every other HyperFrames render — the imperfection is designed in, not left to chance.

Unseeded randomness is the obvious way to break cold-render correctness, but a handful of GSAP lint rules catch subtler seek-order mistakes — relative tweens colliding with another writer, `repeatRefresh` combined with a relative value, function-valued tween vars, DOM measurement inside timeline callbacks — see the [seek-order safety rows](/prompting/rules-and-anti-patterns#seek-order-safety) in the appendix if the linter ever flags one.

*Next: [Transitions](/prompting/transitions) — the same grammar applied to the cut between scenes, not just the motion inside one.*
