> ## Documentation Index
> Fetch the complete documentation index at: https://hyperframes.heygen.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Scroll Camera Story

> A compressed forced-scroll cinematic pass: a tall scene of slotted sections travels past the camera top to bottom, depth layers parallax at different rates, each section rises as the camera reaches it, and the pass decelerates into a held final section.

export const InstallCommand = ({command}) => {
  const [copied, setCopied] = React.useState(false);
  const copy = async () => {
    try {
      if (navigator.clipboard && window.isSecureContext) {
        await navigator.clipboard.writeText(command);
      } else {
        const previous = document.activeElement;
        const scratch = document.createElement("textarea");
        scratch.value = command;
        scratch.setAttribute("readonly", "");
        scratch.style.position = "fixed";
        scratch.style.opacity = "0";
        document.body.appendChild(scratch);
        scratch.select();
        document.execCommand("copy");
        document.body.removeChild(scratch);
        previous?.focus?.();
      }
      setCopied(true);
      setTimeout(() => setCopied(false), 2000);
    } catch {}
  };
  return <div className="hf-install-command not-prose my-4 flex items-stretch overflow-hidden rounded-xl border border-zinc-200 bg-zinc-50 dark:border-zinc-800 dark:bg-zinc-900">
      <code className="flex-1 overflow-x-auto whitespace-nowrap border-r border-zinc-200 px-4 py-3 font-mono text-sm text-zinc-800 dark:border-zinc-800 dark:text-zinc-100">
        {command}
      </code>
      <button type="button" onClick={copy} data-copied={copied ? "true" : "false"} aria-label={`Copy ${command} to the clipboard`} className="hf-install-copy">
        <svg className="hf-install-copy-clipboard" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 18 18" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
          <path d="M14.25 5.25H7.25C6.14543 5.25 5.25 6.14543 5.25 7.25V14.25C5.25 15.3546 6.14543 16.25 7.25 16.25H14.25C15.3546 16.25 16.25 15.3546 16.25 14.25V7.25C16.25 6.14543 15.3546 5.25 14.25 5.25Z" />
          <path d="M2.80103 11.998L1.77203 5.07397C1.61003 3.98097 2.36403 2.96397 3.45603 2.80197L10.38 1.77297C11.313 1.63397 12.19 2.16297 12.528 3.00097" />
        </svg>
        <svg className="hf-install-copy-check" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 18 18" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
          <path d="M2.75 9.5L6.5 13.25L15.25 4.5" />
        </svg>
      </button>
      <span className="hf-install-copy-status" role="status" aria-live="polite">
        {copied ? "Copied" : ""}
      </span>
    </div>;
};

<iframe className="w-full aspect-video rounded-xl border-0 bg-zinc-100 dark:bg-zinc-800" title="scroll-camera-story preview" loading="lazy" srcDoc={`<!doctype html><html><head><meta charset="utf-8"><style>html,body{margin:0;height:100%;overflow:hidden;background:transparent}hyperframes-player{display:block;width:100%;height:100%}</style><script src="https://cdn.jsdelivr.net/npm/@hyperframes/player@0.7/dist/hyperframes-player.global.js"><\/script></head><body><script>fetch("/public/catalog/components/scroll-camera-story.json").then(function(r){return r.json()}).then(function(d){var p=document.createElement("hyperframes-player");p.setAttribute("srcdoc",d.html);p.setAttribute("controls","");p.setAttribute("autoplay","");p.setAttribute("loop","");p.setAttribute("muted","");p.setAttribute("poster","https://static.heygen.ai/hyperframes-oss/docs/images/catalog/components/scroll-camera-story.png");document.body.appendChild(p)});<\/script></body></html>`} />

## Install

<InstallCommand command="npx hyperframes add scroll-camera-story" />

That writes one file: `compositions/components/scroll-camera-story.html`.

## Paste it into your composition

Open `compositions/components/scroll-camera-story.html` and copy what is inside into your own composition.

A component has no size or duration of its own. It takes both from the composition
you paste it into.

## Variables

Every one of these has a default, so the piece works untouched. Set the ones you
want to change on the element:

| Variable   | Default | Accepts                      | What it does                                                                                                      |
| ---------- | ------- | ---------------------------- | ----------------------------------------------------------------------------------------------------------------- |
| `sections` | `3`     | 2 to 4, step 1               | How many skeleton sections ride the pass. A sections slot overrides this with its own child count.                |
| `travel`   | `220`   | 100cqh to 400cqh, step 10cqh | Total camera travel in cqh. The world is 100 + travel cqh tall.                                                   |
| `cues`     | \`\`    | string                       | Comma-separated seconds: arrival times for the sections after the first. Empty keeps the authored default rhythm. |
| `accent`   | `green` | `green`, `blue`, `violet`    | Token the skeleton accents and foreground motes ride.                                                             |
| `exit`     | `none`  | `none`, `fade`, `up`         | Optional departure. None holds the final section.                                                                 |

Set them with `data-variable-values` on the element that mounts it. These are the
defaults, so this behaves exactly like the preview above until you change one:

```html wrap theme={null}
<div
  data-composition-id="scroll-camera-story"
  data-composition-src="compositions/components/scroll-camera-story.html"
  data-variable-values='{"sections":3,"travel":220,"cues":"","accent":"green","exit":"none"}'
></div>
```

## Source

<Accordion title={`scroll-camera-story.html`}>
  ```html theme={null}
  <!doctype html>
  <!--
    scroll-camera-story -- HyperFrames video primitive (camera)

    A compressed forced-scroll cinematic pass: a tall authored scene travels
    past the camera top to bottom. Four depth layers move at different rates
    (far slowest, foreground fastest), sections enter with a soft rise as the
    camera reaches them, and the pass decelerates into a held final section.

    Camera-servo law: all camera state lives in ONE plain object (cam.t, the
    pass progress 0 to 1) plus a drift object, and every layer transform is a
    pure function of that state written by one applyCamera() writer. The world
    wrapper carries the camera translate; depth layers carry derived parallax
    offsets computed in the same writer, so any seek in any order reproduces
    the exact frame. Micro-drift runs INTEGER sine cycles (2 on x-phase, 3 on
    y-phase) that end at exactly zero when the final section lands, so the
    held final section is byte-still.

    Seek-safety trap (banked): cq-unit transform tweens blow up under seeks.
    Nothing here tweens a cq unit. The world height is set ONCE at mount in
    cqh; every tweened transform is percent-based (translate percent of the
    element's own box, gsap yPercent on section cards) derived from plain
    numbers, so no container-query re-resolution ever happens inside a tween.

    Sections are SLOTS. Callers supply content by placing an inert template
    at HOST DOCUMENT level (templates never render, and the runtime wipes the
    host clip's own children on mount):

      <template data-slot="scroll-camera-story-sections">
        <div>first section content</div>
        <div>second section content</div>
      </template>

    Each direct child of the template becomes one section's card content, in
    order (clamped to 2-4 sections). Sections without a slot child keep their
    token skeleton default. Without a slot, the `sections` variable picks how
    many skeleton sections ride the pass.

    Variables (declared in data-composition-variables below):
      - sections (number 2-4, default 3): skeleton section count; a sections
        slot overrides it with its own child count.
      - travel (number cqh, default 220): total camera travel. The world is
        (100 + travel) cqh tall; sections spread evenly along the travel.
      - cues (string, default ""): comma-separated seconds, arrival times for
        the sections AFTER the first (the first section is on screen at
        mount). Empty keeps the authored default rhythm. If one extra value
        is supplied, the first is treated as the mount section's and dropped.
      - accent ("green" | "blue" | "violet", default "green"): green rides
        --brand, blue rides --accent, violet rides --accent-2.
      - exit ("none" | "fade" | "up", default "none"): frame roots own
        transitions; the default holds the final section to the last pixel.

    Envelope, fixed IN and OUT with elastic HOLD only (never timeScale):
      IN_BASE  = 0.85s  stage fade + first section rise
      PASS     = camera moves ending on each arrival cue, quiet register
                 (power2.inOut, longer final move: the pass decelerates)
      HOLD     = elastic; drift ends at zero on the last arrival, then the
                 held final section is dead still
      OUT_BASE = 0.50s  only when exit != none
      If D is too short the fixed phases compress together.

    Wave K laws: L1, camera segments never overlap (each move starts after
    the previous ends, so no mid-motion redirect exists to snap velocity);
    L2, the quiet register is the only register here, no percussive variant.

    Mount contract: the runtime clones only this template. #root fills the
    host box (no data-width/data-height, container-type: size, cq units in
    static styles only), is styled via #root only, and registers one paused
    timeline under the LITERAL "scroll-camera-story" key.
  -->
  <html
    lang="en"
    data-composition-id="scroll-camera-story"
    data-composition-duration="5.5"
    data-composition-variables='[
      { "id": "sections", "type": "number", "role": "content", "label": "Sections", "description": "How many skeleton sections ride the pass. A sections slot overrides this with its own child count.", "default": 3, "min": 2, "max": 4, "step": 1 },
      { "id": "travel", "type": "number", "role": "content", "label": "Travel", "description": "Total camera travel in cqh. The world is 100 + travel cqh tall.", "default": 220, "min": 100, "max": 400, "step": 10, "unit": "cqh" },
      { "id": "cues", "type": "string", "role": "timing", "label": "Cues", "description": "Comma-separated seconds: arrival times for the sections after the first. Empty keeps the authored default rhythm.", "default": "" },
      { "id": "accent", "type": "enum", "role": "style", "label": "Accent", "description": "Token the skeleton accents and foreground motes ride.", "default": "green", "options": [{ "value": "green", "label": "Green" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
      { "id": "exit", "type": "enum", "role": "style", "label": "Exit", "description": "Optional departure. None holds the final section.", "default": "none", "options": [{ "value": "none", "label": "None" }, { "value": "fade", "label": "Fade" }, { "value": "up", "label": "Up" }] }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Scroll Camera Story</title>
    </head>
    <body>
      <template>
        <div id="root" data-composition-id="scroll-camera-story" data-duration="5.5" data-fps="30">
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

            #root {
              position: absolute;
              inset: 0;
              overflow: hidden;
              container-type: size;
              isolation: isolate;
              color: var(--fg, #f8fafc);
              font-family: var(--font-body, ui-sans-serif, system-ui, sans-serif);
              pointer-events: none;
            }

            .scs-clip {
              position: absolute;
              inset: 0;
              overflow: hidden;
              background: var(--bg, transparent);
            }

            .scs-stage {
              position: absolute;
              inset: 0;
              overflow: hidden;
              background:
                radial-gradient(
                  ellipse 120% 70% at 50% 0%,
                  color-mix(in srgb, var(--scs-accent) 6%, transparent) 0%,
                  transparent 60%
                ),
                var(--bg, #0b0c0e);
              will-change: transform, opacity;
            }

            /* ONE world wrapper: the camera translate lives here; depth layers
               below carry derived parallax offsets from the same writer. */
            .scs-world {
              position: absolute;
              top: 0;
              right: 0;
              left: 0;
              will-change: transform;
            }

            .scs-layer {
              position: absolute;
              inset: 0;
              will-change: transform;
            }

            /* far layer: large soft washes, slowest */
            .scs-blob {
              position: absolute;
              width: 64cqmin;
              height: 64cqmin;
              border-radius: 50%;
              background: radial-gradient(
                circle,
                color-mix(in srgb, var(--scs-accent) 11%, transparent) 0%,
                color-mix(in srgb, var(--scs-accent) 5%, transparent) 45%,
                transparent 70%
              );
            }

            .scs-blob:nth-child(1) {
              top: 2%;
              left: -14cqmin;
            }

            .scs-blob:nth-child(2) {
              top: 17%;
              right: -18cqmin;
              width: 78cqmin;
              height: 78cqmin;
              background: radial-gradient(
                circle,
                color-mix(in srgb, var(--fg, #f8fafc) 6%, transparent) 0%,
                color-mix(in srgb, var(--fg, #f8fafc) 3%, transparent) 45%,
                transparent 70%
              );
            }

            .scs-blob:nth-child(3) {
              top: 34%;
              left: 6cqw;
            }

            .scs-blob:nth-child(4) {
              top: 48%;
              right: 2cqw;
              width: 56cqmin;
              height: 56cqmin;
            }

            /* mid layer: hairline geometry */
            .scs-ring {
              position: absolute;
              width: 16cqmin;
              height: 16cqmin;
              border: 0.16cqmin solid color-mix(in srgb, var(--fg, #f8fafc) 12%, transparent);
              border-radius: 50%;
            }

            .scs-rule {
              position: absolute;
              width: 12cqmin;
              height: 0.16cqmin;
              background: color-mix(in srgb, var(--fg, #f8fafc) 14%, transparent);
            }

            .scs-plus {
              position: absolute;
              width: 3.4cqmin;
              height: 3.4cqmin;
            }

            .scs-plus::before,
            .scs-plus::after {
              position: absolute;
              content: "";
              background: color-mix(in srgb, var(--fg, #f8fafc) 18%, transparent);
            }

            .scs-plus::before {
              top: 0;
              bottom: 0;
              left: calc(50% - 0.08cqmin);
              width: 0.16cqmin;
            }

            .scs-plus::after {
              top: calc(50% - 0.08cqmin);
              right: 0;
              left: 0;
              height: 0.16cqmin;
            }

            .scs-ring:nth-of-type(1) {
              top: 6%;
              right: 12cqw;
            }

            .scs-ring:nth-of-type(2) {
              top: 30%;
              left: 9cqw;
              width: 10cqmin;
              height: 10cqmin;
            }

            .scs-ring:nth-of-type(3) {
              top: 52%;
              right: 8cqw;
              width: 22cqmin;
              height: 22cqmin;
              border-color: color-mix(in srgb, var(--fg, #f8fafc) 8%, transparent);
            }

            .scs-rule:nth-of-type(1) {
              top: 14%;
              left: 12cqw;
              transform: rotate(90deg);
            }

            .scs-rule:nth-of-type(2) {
              top: 40%;
              right: 16cqw;
            }

            .scs-plus:nth-of-type(1) {
              top: 22%;
              right: 22cqw;
            }

            .scs-plus:nth-of-type(2) {
              top: 47%;
              left: 18cqw;
            }

            .scs-plus:nth-of-type(3) {
              top: 9%;
              left: 30cqw;
            }

            /* foreground layer: small accent motes, fastest */
            .scs-mote {
              position: absolute;
              width: 1cqmin;
              height: 1cqmin;
              border-radius: 50%;
              background: color-mix(in srgb, var(--scs-accent) 55%, transparent);
            }

            .scs-mote:nth-child(1) {
              top: 7%;
              left: 8cqw;
            }

            .scs-mote:nth-child(2) {
              top: 21%;
              right: 10cqw;
              width: 0.7cqmin;
              height: 0.7cqmin;
            }

            .scs-mote:nth-child(3) {
              top: 43%;
              left: 6cqw;
              width: 1.3cqmin;
              height: 1.3cqmin;
              background: color-mix(in srgb, var(--scs-accent) 40%, transparent);
            }

            .scs-mote:nth-child(4) {
              top: 66%;
              right: 7cqw;
            }

            .scs-mote:nth-child(5) {
              top: 88%;
              left: 4cqw;
              width: 0.8cqmin;
              height: 0.8cqmin;
            }

            /* sections: a static positioner zone per section, a rising card in it */
            .scs-section {
              position: absolute;
              right: 10cqw;
              left: 10cqw;
              display: grid;
              place-items: center;
              height: 84cqh;
            }

            .scs-card {
              display: flex;
              flex-direction: column;
              gap: var(--space-2, 2.2cqmin);
              width: min(64cqw, 150cqh);
              max-height: 76cqh;
              padding: var(--space-3, 3.4cqmin);
              overflow: hidden;
              border: 0.16cqmin solid color-mix(in srgb, var(--border, #475569) 70%, transparent);
              border-radius: var(--radius, 2cqmin);
              background: color-mix(in srgb, var(--surface, #0b1016) 88%, var(--bg, #05070c));
              box-shadow: 0 2.4cqh 7cqh color-mix(in srgb, var(--bg, #000000) 34%, transparent);
              will-change: transform, opacity;
            }

            .scs-chiprow {
              display: flex;
              align-items: center;
              gap: var(--space-1, 1.6cqmin);
            }

            .scs-chip {
              padding: 0.7cqmin 1.5cqmin;
              border: 0.14cqmin solid color-mix(in srgb, var(--scs-accent) 45%, transparent);
              border-radius: 999px;
              color: color-mix(in srgb, var(--scs-accent) 80%, var(--fg, #f8fafc));
              font-family: var(--font-mono, ui-monospace, "SF Mono", Menlo, Consolas, monospace);
              font-size: 2cqmin;
              font-weight: 600;
              letter-spacing: 0.14em;
              line-height: 1;
            }

            .scs-chiprule {
              flex: 1;
              height: 0.14cqmin;
              background: color-mix(in srgb, var(--border, #475569) 60%, transparent);
            }

            .scs-bar {
              height: 1.4cqmin;
              border-radius: 999px;
              background: color-mix(in srgb, var(--fg, #f8fafc) 12%, transparent);
            }

            .scs-bar.scs-heading {
              width: 62%;
              height: 3.4cqmin;
              background: color-mix(in srgb, var(--fg, #f8fafc) 24%, transparent);
            }

            .scs-bar.scs-sub {
              width: 44%;
            }

            .scs-minis {
              display: grid;
              grid-template-columns: repeat(3, minmax(0, 1fr));
              gap: 2cqmin;
              margin-top: 0.6cqmin;
            }

            .scs-mini {
              display: flex;
              flex-direction: column;
              gap: 1.4cqmin;
              padding: 2cqmin;
              border: 0.14cqmin solid color-mix(in srgb, var(--border, #475569) 55%, transparent);
              border-radius: calc(var(--radius, 2cqmin) * 0.7);
              background: color-mix(in srgb, var(--bg, #05070c) 32%, transparent);
            }

            .scs-mini .scs-bar {
              width: 62%;
            }

            .scs-mini-block {
              height: 7cqmin;
              border-radius: calc(var(--radius, 2cqmin) * 0.5);
              background: color-mix(in srgb, var(--fg, #f8fafc) 7%, transparent);
            }

            .scs-mini:nth-child(2) .scs-mini-block {
              background: color-mix(in srgb, var(--scs-accent) 18%, transparent);
            }

            .scs-rowline {
              display: flex;
              align-items: center;
              gap: var(--space-1, 1.6cqmin);
            }

            .scs-dot {
              flex: 0 0 auto;
              width: 1.5cqmin;
              height: 1.5cqmin;
              border-radius: 50%;
              background: color-mix(in srgb, var(--fg, #f8fafc) 22%, transparent);
            }

            .scs-rowline:nth-of-type(2) .scs-dot {
              background: color-mix(in srgb, var(--scs-accent) 70%, transparent);
            }

            .scs-rowline .scs-bar {
              flex: 1;
              max-width: 72%;
            }

            .scs-section[data-close] .scs-card {
              align-items: center;
              text-align: center;
            }

            .scs-section[data-close] .scs-bar.scs-heading {
              width: 52%;
            }

            .scs-section[data-close] .scs-bar.scs-sub {
              width: 34%;
            }

            .scs-pill {
              margin-top: 1.2cqmin;
              padding: 1.4cqmin 3.4cqmin;
              border-radius: 999px;
              background: color-mix(in srgb, var(--scs-accent) 82%, var(--surface, #0b1016));
              color: var(--bg, #0b0c0e);
              font-family: var(--font-mono, ui-monospace, "SF Mono", Menlo, Consolas, monospace);
              font-size: 2.1cqmin;
              font-weight: 600;
              letter-spacing: 0.12em;
              line-height: 1;
            }
          </style>

          <div
            id="scroll-camera-story-clip"
            class="scs-clip clip"
            data-start="0"
            data-duration="5.5"
            data-track-index="0"
          >
            <div class="scs-stage" role="img" aria-label="Cinematic scroll pass over a tall scene">
              <div class="scs-world">
                <div class="scs-layer scs-far" aria-hidden="true">
                  <span class="scs-blob"></span>
                  <span class="scs-blob"></span>
                  <span class="scs-blob"></span>
                  <span class="scs-blob"></span>
                </div>
                <div class="scs-layer scs-mid" aria-hidden="true">
                  <span class="scs-ring"></span>
                  <span class="scs-ring"></span>
                  <span class="scs-ring"></span>
                  <span class="scs-rule"></span>
                  <span class="scs-rule"></span>
                  <span class="scs-plus"></span>
                  <span class="scs-plus"></span>
                  <span class="scs-plus"></span>
                </div>
                <div class="scs-layer scs-content">
                  <div class="scs-section" aria-hidden="true">
                    <div class="scs-card">
                      <div class="scs-chiprow">
                        <span class="scs-chip">01</span>
                        <span class="scs-chiprule"></span>
                      </div>
                      <span class="scs-bar scs-heading"></span>
                      <span class="scs-bar" style="width: 74%"></span>
                      <span class="scs-bar scs-sub"></span>
                    </div>
                  </div>
                  <div class="scs-section" aria-hidden="true">
                    <div class="scs-card">
                      <div class="scs-chiprow">
                        <span class="scs-chip">02</span>
                        <span class="scs-chiprule"></span>
                      </div>
                      <span class="scs-bar scs-heading" style="width: 46%"></span>
                      <div class="scs-minis">
                        <div class="scs-mini">
                          <span class="scs-bar"></span>
                          <span class="scs-mini-block"></span>
                        </div>
                        <div class="scs-mini">
                          <span class="scs-bar"></span>
                          <span class="scs-mini-block"></span>
                        </div>
                        <div class="scs-mini">
                          <span class="scs-bar"></span>
                          <span class="scs-mini-block"></span>
                        </div>
                      </div>
                    </div>
                  </div>
                  <div class="scs-section" aria-hidden="true">
                    <div class="scs-card">
                      <div class="scs-chiprow">
                        <span class="scs-chip">03</span>
                        <span class="scs-chiprule"></span>
                      </div>
                      <span class="scs-bar scs-heading" style="width: 40%"></span>
                      <div class="scs-rowline">
                        <span class="scs-dot"></span>
                        <span class="scs-bar"></span>
                      </div>
                      <div class="scs-rowline">
                        <span class="scs-dot"></span>
                        <span class="scs-bar" style="max-width: 58%"></span>
                      </div>
                      <div class="scs-rowline">
                        <span class="scs-dot"></span>
                        <span class="scs-bar" style="max-width: 66%"></span>
                      </div>
                    </div>
                  </div>
                  <div class="scs-section" data-close aria-hidden="true">
                    <div class="scs-card">
                      <div class="scs-chiprow" style="align-self: stretch">
                        <span class="scs-chip">04</span>
                        <span class="scs-chiprule"></span>
                      </div>
                      <span class="scs-bar scs-heading"></span>
                      <span class="scs-bar scs-sub"></span>
                      <span class="scs-pill">&gt;_</span>
                    </div>
                  </div>
                </div>
                <div class="scs-layer scs-fore" aria-hidden="true">
                  <span class="scs-mote"></span>
                  <span class="scs-mote"></span>
                  <span class="scs-mote"></span>
                  <span class="scs-mote"></span>
                  <span class="scs-mote"></span>
                </div>
              </div>
            </div>
          </div>

          <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
          <script>
            (function () {
              "use strict";

              var root = document.getElementById("root");
              var stage = root.querySelector(".scs-stage");
              var world = root.querySelector(".scs-world");
              var layerFar = root.querySelector(".scs-far");
              var layerMid = root.querySelector(".scs-mid");
              var layerFore = root.querySelector(".scs-fore");
              var sectionElements = Array.prototype.slice.call(root.querySelectorAll(".scs-section"));
              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};

              function num(value, fallback, min, max) {
                var parsed = parseFloat(value);
                if (!isFinite(parsed)) parsed = fallback;
                return Math.min(max, Math.max(min, parsed));
              }

              var travel = num(vars.travel, 220, 100, 400);
              var sectionsVar = Math.round(num(vars.sections, 3, 2, 4));
              // Each enum choice routes to a DIFFERENT contract token so the
              // variable stays meaningful under a theme.
              var accentColors = {
                green: "var(--brand, #71f5a7)",
                blue: "var(--accent, #61a8ff)",
                violet: "var(--accent-2, #c5a3ff)",
              };
              var accent = Object.prototype.hasOwnProperty.call(accentColors, vars.accent)
                ? vars.accent
                : "green";
              var exitMode = vars.exit === "fade" || vars.exit === "up" ? vars.exit : "none";

              root.style.setProperty("--scs-accent", accentColors[accent]);

              // SLOT. Caller templates live at HOST DOCUMENT level (the mount
              // wipes host-clip children, and templates never render). Each
              // direct child of the slot template becomes one section's card
              // content, in order.
              var hostDoc = root.ownerDocument;
              var slotChildren = [];
              try {
                var slotTemplate = hostDoc.querySelector(
                  'template[data-slot="scroll-camera-story-sections"]',
                );
                if (slotTemplate)
                  slotChildren = Array.prototype.slice.call(slotTemplate.content.children);
              } catch (error) {
                slotChildren = [];
              }

              var count = Math.min(4, Math.max(2, slotChildren.length || sectionsVar));
              sectionElements.forEach(function (section, index) {
                if (index >= count) {
                  section.remove();
                  return;
                }
                if (slotChildren[index]) {
                  var card = section.querySelector(".scs-card");
                  while (card.firstChild) card.removeChild(card.firstChild);
                  card.appendChild(hostDoc.importNode(slotChildren[index], true));
                }
              });
              var sections = sectionElements.slice(0, count);
              var cards = sections.map(function (section) {
                return section.querySelector(".scs-card");
              });

              // World geometry, set ONCE at mount in cqh (static style, never
              // tweened; the seek trap is cq units INSIDE tweens). Section i
              // centers at camera progress i / (count - 1) along the travel.
              world.style.height = (100 + travel).toFixed(2) + "cqh";
              sections.forEach(function (section, index) {
                var progress = index / (count - 1);
                section.style.top = (50 + progress * travel - 42).toFixed(2) + "cqh";
              });

              /* ===== Camera (camera-servo law): one plain state object, one
                 writer. cam.t is the pass progress 0..1. The world translates
                 by percent of its OWN height (a pure number: travel out of
                 100 + travel), and each depth layer gets a derived parallax
                 offset so its net rate is RATE x the camera rate. No cq units
                 are ever tweened. ===== */
              var F = (100 * travel) / (100 + travel); // percent of world height per full pass
              var RATE_FAR = 0.35;
              var RATE_MID = 0.65;
              var RATE_FORE = 1.12;
              var cam = { t: 0 };
              var drift = { p: 0, dx: 0, dy: 0 };
              function applyCamera() {
                var y = -cam.t * F;
                world.style.transform = "translate(" + drift.dx + "%, " + (y + drift.dy) + "%)";
                layerFar.style.transform = "translateY(" + cam.t * F * (1 - RATE_FAR) + "%)";
                layerMid.style.transform = "translateY(" + cam.t * F * (1 - RATE_MID) + "%)";
                layerFore.style.transform = "translateY(" + cam.t * F * (1 - RATE_FORE) + "%)";
              }
              applyCamera();

              // Envelope: fixed IN/OUT, elastic HOLD, never time-scaled.
              var IN_BASE = 0.85;
              var OUT_BASE = exitMode === "none" ? 0 : 0.5;
              var PASS_MIN = 1.2;
              var duration = Math.max(0.001, parseFloat(root.dataset.duration || "5.5"));
              var totalBase = IN_BASE + PASS_MIN + OUT_BASE;
              var scale = duration < totalBase ? duration / totalBase : 1;
              var IN = IN_BASE * scale;
              var OUT = OUT_BASE * scale;
              var usable = duration - OUT;

              // Arrival schedule: defaults decelerate into a held final
              // section; the cues variable overrides arrivals for sections
              // after the first.
              var HOLD_MIN = Math.min(1.3, Math.max(0.45, usable * 0.24));
              var lastDefault = Math.max(IN + 0.9 * scale, usable - HOLD_MIN);
              var firstDefault = Math.min(lastDefault, IN + 1.15 * scale);
              var arrivals = [];
              var index;
              for (index = 1; index < count; index += 1) {
                arrivals.push(
                  count === 2
                    ? lastDefault
                    : firstDefault + ((index - 1) / (count - 2)) * (lastDefault - firstDefault),
                );
              }
              var cueValues = String(vars.cues == null ? "" : vars.cues)
                .split(",")
                .map(function (part) {
                  return parseFloat(part);
                })
                .filter(function (value) {
                  return isFinite(value);
                });
              // Lenient by one: a list with an extra leading value is treated
              // as including the mount section's arrival.
              if (cueValues.length === count) cueValues = cueValues.slice(1);
              if (cueValues.length >= count - 1) {
                arrivals = cueValues.slice(0, count - 1);
              }
              var floor = IN + 0.35 * scale;
              for (index = 0; index < arrivals.length; index += 1) {
                var clamped = Math.min(usable - 0.3 * scale, Math.max(floor, arrivals[index]));
                arrivals[index] = clamped;
                floor = clamped + 0.4 * scale;
              }
              var lastArrival = arrivals.length > 0 ? arrivals[arrivals.length - 1] : IN;

              var tl = gsap.timeline({ paused: true });

              // IN: the stage fades up while the first section rises.
              tl.fromTo(
                stage,
                { opacity: 0 },
                { opacity: 1, duration: Math.min(0.6 * scale, IN), ease: "power2.out" },
                0,
              );

              // Section rises: each card lands exactly on its arrival cue.
              // yPercent only (percent of the card's own box), never cq units.
              cards.forEach(function (card, cardIndex) {
                var arrive = cardIndex === 0 ? IN : arrivals[cardIndex - 1];
                var rise = Math.min(
                  0.75 * scale,
                  Math.max(0.25, arrive - (cardIndex === 0 ? 0.1 : 0)),
                );
                tl.fromTo(
                  card,
                  { opacity: 0, yPercent: 10 },
                  { opacity: 1, yPercent: 0, duration: rise, ease: "power3.out" },
                  arrive - rise,
                );
              });

              // Camera pass: one non-overlapping segment per arrival, quiet
              // register (L2). Each move ends exactly on its cue; the final
              // move runs longer, so the pass decelerates into the hold. No
              // segment starts before the previous ends (L1: no mid-motion
              // redirect exists to snap velocity).
              var previousEnd = IN * 0.7;
              arrivals.forEach(function (arrive, arriveIndex) {
                var isLast = arriveIndex === arrivals.length - 1;
                var gap = arrive - previousEnd - 0.1 * scale;
                var move = Math.max(0.3, Math.min(isLast ? 1.7 : 1.25, gap));
                tl.to(
                  cam,
                  {
                    t: (arriveIndex + 1) / (count - 1),
                    duration: move,
                    ease: "power2.inOut",
                    onUpdate: applyCamera,
                  },
                  arrive - move,
                );
                previousEnd = arrive;
              });

              // Micro-drift: 2 and 3 INTEGER sine cycles ending at exactly
              // zero when the final section lands, so the held final section
              // is byte-still and every seek reproduces the same frame.
              if (lastArrival >= 1.2) {
                tl.to(
                  drift,
                  {
                    p: Math.PI * 2 * 2,
                    duration: lastArrival,
                    ease: "none",
                    onUpdate: function () {
                      drift.dx = Math.sin(drift.p) * 0.06;
                      drift.dy = Math.sin(drift.p * 1.5) * 0.08;
                      applyCamera();
                    },
                  },
                  0,
                );
              }

              // OUT: only when exit != none; the default holds the last frame.
              if (exitMode !== "none") {
                var outStart = duration - OUT;
                tl.to(stage, { opacity: 0, duration: OUT, ease: "power2.in" }, outStart);
                if (exitMode === "up") {
                  tl.to(stage, { yPercent: -4, duration: OUT, ease: "power2.in" }, outStart);
                }
              }

              tl.seek(0);
              window.__timelines = window.__timelines || {};
              window.__timelines["scroll-camera-story"] = tl;
            })();
          </script>
        </div>
      </template>
    </body>
  </html>
  ```
</Accordion>

Tagged `camera` `scroll` `parallax` `story` `sections` `slot` `servo`.

## Related topics

* [Browse the complete Catalog](/catalog)
* [Add assets and Catalog items in Studio](/studio/assets-and-blocks)
* [Build a richer composition](/go-further)


## Related topics

- [Scroll Feed](/catalog/components/scroll-feed.md)
- [Code animations](/prompting/code-blocks.md)
- [Chart Story](/catalog/components/chart-story.md)
