# Motion, film and sound

Release 0.3.0-draft.1 · Development standards

Movement should explain change or establish atmosphere. The person using the experience remains in control.

## A small vocabulary

| Purpose | Recommended starting behaviour | Static alternative |
| --- | --- | --- |
| Hover / focus feedback | 120–180 ms restrained colour or opacity change | Immediate state change |
| Panel transition | 180–280 ms ease-out; short travel of 8–16 px if useful | Direct replacement |
| Section entrance | 300–500 ms; low distance; once, not on every scroll | Fully visible content |
| Workflow explanation | Deliberate steps with readable labels and a pause at review | Numbered diagram |
| Ambient material scene | Slow environmental motion without urgent flashing | Chosen still poster |

These ranges guide production trials. They do not describe an installed animation system. Avoid bounce, elastic logo motion and gratuitous parallax. A loading indicator communicates pending work; a progress percentage requires a real measurable basis.

## Storyboards across formats

**Landscape 16:9:** establish the task → show one material movement → hold at the review point → end on the supplied mark, descriptor and next action. **Portrait 9:16:** begin close to the meaningful object; keep the central action visible; place separately composed captions in a verified safe area; use a dedicated end card. Do not simply cut a landscape film down the middle.

Hold key copy long enough to read aloud comfortably. Check first, intermediate and final frames plus the whole duration. Provide captions for speech and meaningful audio. Lower thirds name real people/roles accurately. Thumbnails should work without motion and not imply a result the film does not demonstrate.

## Sound

No autoplay audio. Use sound only when it improves comprehension or a deliberately played piece. Speech takes priority over music; duck the bed and check on ordinary phone speakers and headphones. Set delivery loudness/peaks against the actual platform brief and record the measured export, rather than inventing a universal target. Music, voices and effects need suitable licences and provenance. No sonic signature is approved by this release.

Check pause/replay controls where needed, reduced-motion output, flashing risk and readability over moving backgrounds. A still export is not proof that the full film is safe or complete.

## Operating rules

### MOT-001 — Make motion purposeful

- **Do:** Tie movement to explanation, state change or a controlled atmosphere.
- **When:** Web, presentations and video
- **Variation:** Timing adjustments after readability and performance review.
- **Avoid:** Unnecessary looping, flashing or logo geometry transformations.
- **Check:** State the motion’s purpose and inspect the full duration.

### MOT-002 — Provide an equivalent quiet path

- **Do:** Preserve information in reduced-motion and static versions.
- **When:** Motion-based content
- **Variation:** A poster, numbered diagram or immediate state change.
- **Avoid:** Requiring animation to reach essential content or understand status.
- **Check:** Compare meaning and task completion with motion disabled.

### SND-001 — Make audio deliberate and usable

- **Do:** Require a user-initiated playback path, clear speech and licensed sources.
- **When:** Film, sound effects and music
- **Variation:** Context-appropriate music with captions and controlled mix.
- **Avoid:** Autoplay audio or claiming an unreviewed sonic identity.
- **Check:** Check rights, caption accuracy, actual export levels and ordinary-device playback.

[Handbook contents](README.md) · [AI rules](../ai/rules.json)