> ## Documentation Index
> Fetch the complete documentation index at: https://hyperframes-release-v0-8-51.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Shutter Slam

> One word thrown through six single-property beats under integrated shutter blur — two translate slams, a scale punch, then a full turn about each axis — on the measured easing of the After Effects export the shutter model was fitted to

export const InstallCommand = ({command, item}) => {
  const [copied, setCopied] = React.useState(false);
  const [tuned, setTuned] = React.useState("");
  React.useEffect(() => {
    if (!item) return;
    const read = () => {
      try {
        const raw = new URLSearchParams(window.location.search).get(`vars-${item}`);
        if (!raw) return setTuned("");
        const parsed = JSON.parse(raw);
        if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) return setTuned("");
        if (Object.keys(parsed).length === 0) return setTuned("");
        setTuned(` --vars '${JSON.stringify(parsed)}'`);
      } catch {
        setTuned("");
      }
    };
    read();
    window.addEventListener("hf-vars-changed", read);
    window.addEventListener("popstate", read);
    return () => {
      window.removeEventListener("hf-vars-changed", read);
      window.removeEventListener("popstate", read);
    };
  }, [item]);
  const fullCommand = `${command}${tuned}`;
  const copy = async () => {
    try {
      if (navigator.clipboard && window.isSecureContext) {
        await navigator.clipboard.writeText(fullCommand);
      } else {
        const previous = document.activeElement;
        const scratch = document.createElement("textarea");
        scratch.value = fullCommand;
        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">
        {fullCommand}
      </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>;
};

## Install

<InstallCommand command="npx hyperframes add shutter-slam" item="shutter-slam" />

That writes one file: `compositions/components/shutter-slam.html`.

<iframe className="w-full aspect-video rounded-xl border-0 bg-zinc-100 dark:bg-zinc-800" title="shutter-slam 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@latest/dist/hyperframes-player.global.js"><\/script></head><body><script>fetch("/public/catalog/components/shutter-slam.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/shutter-slam.png");document.body.appendChild(p)});<\/script></body></html>`} />

## Paste it into your composition

Open `compositions/components/shutter-slam.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.

## Source

<Accordion title="shutter-slam.html">
  ```html theme={null}
  <!doctype html>
  <!--
    shutter-slam: HyperFrames video primitive

    One word thrown through six single-property beats, every frame integrated
    over the camera shutter: two hard translate slams, a scale punch, then a
    full turn about each of the three axes. It is the motion-blur primitive's
    reference case — the beats are the ones measured off the After Effects
    export the shutter model was fitted to, so every driver the model covers
    (translate, scale, rotate, 3D rotate) is exercised in one mount.

    Variables:
      text: the slammed word
      accent: green, blue, or violet word color
      blur: shutter (integrated) or none (one instant per frame)
      cues: comma seconds from mount start for each of the six beats
      exit: none, fade, or up

    Envelope, fixed beats with elastic HOLD:
      BEATS = 5.97s at the authored rhythm (0.3s per slam, 0.6s per 3D turn,
              0.73s for the Z turn)
      HOLD  = max(0, D - BEATS - OUT), the word at rest
      OUT   = 0.40s when exit is fade or up, else 0
      If D is shorter than BEATS + OUT the beat clock compresses; the timeline
      is never time-scaled.

    Easing is power2.inOut because it measured best, not because it was the
    default. A bezier fitted to the reference's own bbox centres looks like the
    better curve on paper and renders worse: 1.3 dB down on the horizontal slam,
    1.0 dB up on the vertical turn, 0.25 dB down over the clip. A blurred bbox
    centre is the shutter window's average, not the instant, so on an
    accelerating segment the fit is measuring its own blur.

    Amplitudes are fractions of the host box (32.1cqw, 30.5cqh), so the slams
    leave the frame on a wide mount exactly as far as they do on the reference.
    The scale punch overflows on purpose; the clip crops it.

    Mount contract: the runtime clones only this template. #root fills the host
    box, establishes the container query basis, and has no data-width or
    data-height. One paused timeline registers under the literal shutter-slam
    key.
  -->
  <html
    lang="en"
    data-composition-id="shutter-slam"
    data-composition-duration="6"
    data-composition-variables='[
      { "id": "text", "type": "string", "role": "content", "label": "Word", "description": "The word driven through the six beats.", "default": "MOTION" },
      { "id": "accent", "type": "enum", "role": "style", "label": "Accent", "description": "Word color.", "default": "green", "options": [{ "value": "green", "label": "Green" }, { "value": "blue", "label": "Blue" }, { "value": "violet", "label": "Violet" }] },
      { "id": "blur", "type": "enum", "role": "motion", "label": "Blur", "description": "Integrate each frame over the shutter window, or capture one instant per frame.", "default": "shutter", "options": [{ "value": "shutter", "label": "Shutter" }, { "value": "none", "label": "None" }] },
      { "id": "cues", "type": "string", "role": "motion", "label": "Cues", "description": "Comma seconds from mount start for each of the six beats; empty keeps the authored rhythm.", "default": "" },
      { "id": "exit", "type": "enum", "role": "motion", "label": "Exit", "description": "How the word leaves.", "default": "none", "options": [{ "value": "none", "label": "None" }, { "value": "fade", "label": "Fade" }, { "value": "up", "label": "Up" }] }
    ]'
  >
    <head>
      <meta charset="UTF-8" />
      <title>Shutter Slam</title>
    </head>
    <body>
      <template>
        <div id="root" data-composition-id="shutter-slam" data-duration="6" data-fps="30">
          <style>
            *,
            *::before,
            *::after {
              box-sizing: border-box;
            }

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

            .ss-clip {
              position: absolute;
              inset: 0;
              width: 100cqw;
              height: 100cqh;
              overflow: hidden;
            }

            /* The turns need a perspective ancestor, and the blur reads its
               perspective off the word's own parent, so the stage that carries
               it must be the word's direct parent. */
            .ss-stage {
              position: absolute;
              inset: 0;
              display: grid;
              place-items: center;
              perspective: 104cqw;
            }

            .ss-word {
              color: var(--ss-accent, #71f5a7);
              font-size: var(--ss-font-size, min(14cqw, 26cqh));
              font-weight: 900;
              line-height: 1;
              letter-spacing: -0.02em;
              white-space: nowrap;
              transform-origin: 50% 50%;
              will-change: transform;
            }
          </style>

          <div
            id="shutter-slam-clip"
            class="ss-clip clip"
            data-start="0"
            data-duration="6"
            data-track-index="0"
          >
            <div class="ss-stage">
              <div class="ss-word" id="shutter-slam-word" role="heading" aria-level="1"></div>
            </div>
          </div>

          <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
          <script>
            (function () {
              /* SHUTTER_SNIPPET_START */
              if (!window._hfMbUid) window._hfMbUid = 0;
              if (!window._hfMbAttached) window._hfMbAttached = new WeakSet();
              if (!window._hfMbSkipped) window._hfMbSkipped = new WeakSet();
              if (!window._hfMbProxies) window._hfMbProxies = new WeakSet();
              if (!window._hfMbTimeline) window._hfMbTimeline = new WeakMap();
              if (!window._hfMbWarned) window._hfMbWarned = new WeakSet();

              // The declarative form. A copy of a target must not carry it, or the copy is swept
              // as a target of its own; the group's own marker is `data-hf-motion-blur-group`.
              var SWEEP_ATTR = "data-hf-motion-blur";
              // About eight seconds. Long enough for an asynchronously mounted sub-composition, short
              // enough that a page with a genuine mistake in it reports before anyone stops watching.
              var POLL_MS = 32;
              var POLL_TICKS = 250;
              var SWEEP_SELECTOR = "[" + SWEEP_ATTR + "]";
              var OPTION_KEYS = ["shutterAngle", "shutterPhase", "samplesPerFrame", "fps"];

              // A copy is a deep clone, so the attribute rides along on the root AND on every marked
              // descendant. Any one left behind is swept as a target of its own, which clones again.
              var COPY_STRIP = [SWEEP_ATTR, "data-composition-id", "data-fps"];

              function stripAttrs(el) {
                for (var a = 0; a < COPY_STRIP.length; a++) el.removeAttribute(COPY_STRIP[a]);
              }

              function stripCopyAttrs(root) {
                stripAttrs(root);
                var inner = root.querySelectorAll("[" + COPY_STRIP.join("],[") + "]");
                for (var i = 0; i < inner.length; i++) stripAttrs(inner[i]);
              }

              // Shutter length is measured in frames, so the snippet must know the composition
              // frame rate: explicit option, else the target's OWN root, else the first root in
              // the document, else 30. The target's root is what makes two compositions on one
              // page read their own data-fps instead of sharing the first one written.
              function resolveFps(optionFps, target) {
                var explicit = Number(optionFps);
                if (explicit > 0) return explicit;

                var scoped = target ? target.closest("[data-composition-id][data-fps]") : null;
                var root = scoped || document.querySelector("[data-composition-id][data-fps]");
                var rootFps = root ? Number(root.getAttribute("data-fps")) : 0;
                if (rootFps > 0) return rootFps;

                return 30;
              }

              function numOption(value, fallback) {
                return value !== undefined ? Number(value) : fallback;
              }

              // A resolved `transform` is either "none", a 2D matrix(a,b,c,d,e,f) or a 3D
              // matrix3d of 16. Splitting the numbers into the linear part and the
              // translation is what lets the deadband below use a pixel tolerance on the
              // one and an angle/ratio tolerance on the other.
              function parseTransform(value) {
                if (!value || value === "none") return { linear: [1, 0, 0, 1], translate: [0, 0, 0] };
                var nums = value
                  .slice(value.indexOf("(") + 1, -1)
                  .split(",")
                  .map(parseFloat);
                if (nums.length === 16) {
                  return {
                    linear: [
                      nums[0],
                      nums[1],
                      nums[2],
                      nums[4],
                      nums[5],
                      nums[6],
                      nums[8],
                      nums[9],
                      nums[10],
                      nums[3],
                      nums[7],
                      nums[11],
                      nums[15],
                    ],
                    translate: [nums[12], nums[13], nums[14]],
                  };
                }
                return {
                  linear: [nums[0], nums[1], nums[2], nums[3]],
                  translate: [nums[4], nums[5], 0],
                };
              }

              // Deadband: half a pixel of travel, a thousandth of a unit of linear change,
              // about 0.06 degrees or 0.1% of scale. Below it the average is the source.
              // The 2D and 3D forms have different arities, so a change of form counts as
              // movement rather than being compared component by component.
              function differs(a, b) {
                if (a.linear.length !== b.linear.length) return true;
                for (var i = 0; i < a.linear.length; i++) {
                  if (Math.abs(a.linear[i] - b.linear[i]) > 0.001) return true;
                }
                for (var j = 0; j < 3; j++) {
                  if (Math.abs(a.translate[j] - b.translate[j]) > 0.5) return true;
                }
                return false;
              }

              window.attachMotionBlur = function (selector, tl, opts) {
                opts = opts || {};
                var shutterAngle = numOption(opts.shutterAngle, 720);
                var shutterPhase = numOption(opts.shutterPhase, -360);
                var requestedSamples = numOption(opts.samplesPerFrame, 16);
                var samples = Number.isFinite(requestedSamples)
                  ? Math.max(2, Math.min(64, Math.round(requestedSamples)))
                  : 16;
                var items = Array.isArray(selector) ? selector : [selector];
                var targets = items.reduce(function (acc, s) {
                  if (typeof s === "string") {
                    document.querySelectorAll(s).forEach(function (el) {
                      acc.push(el);
                    });
                  } else if (s instanceof Element) {
                    acc.push(s);
                  }
                  return acc;
                }, []);

                // `samples` counts sub-intervals of the shutter window, so there is one copy at
                // every interval boundary — both ends of the window included — and each carries
                // 1/samples of the source. That is what the reference export shows: the outermost
                // copy sits exactly one frame away from the frame time, not half a step short.
                var copies = samples + 1;
                var alpha = String(1 / samples);

                // A copy is styled by nothing that selected the original: dropping the id also
                // drops every `#id` rule that gave it size, colour and font. So each copy carries
                // its own resolved style inline. Chrome returns "" for a computed style's cssText,
                // so the declarations are enumerated rather than taken wholesale.
                function resolvedStyles(source, out) {
                  var cs = getComputedStyle(source);
                  var text = "";
                  for (var i = 0; i < cs.length; i++) {
                    text += cs[i] + ":" + cs.getPropertyValue(cs[i]) + ";";
                  }
                  // A copy is a still of one instant. Left live, an inherited transition or
                  // keyframe animation would carry it somewhere the timeline never sampled.
                  out.push(text + "transition:none;animation:none;");
                  for (var c = 0; c < source.children.length; c++) {
                    resolvedStyles(source.children[c], out);
                  }
                  return out;
                }

                function paintResolvedStyles(copy, styles, cursor) {
                  copy.style.cssText = styles[cursor.i++];
                  for (var c = 0; c < copy.children.length; c++) {
                    paintResolvedStyles(copy.children[c], styles, cursor);
                  }
                }

                // Perspective applies to a parent's children only, and a copy is a grandchild.
                // Sharing the parent's 3D context would need preserve-3d on the group, which
                // mix-blend-mode flattens, so each copy carries the perspective itself. See the
                // header for what that does to the vanishing point.
                function parentPerspective(el) {
                  var value = el.parentNode ? getComputedStyle(el.parentNode).perspective : "none";
                  return value && value !== "none" ? "perspective(" + value + ") " : "";
                }

                function attachOne(el) {
                  var group = document.createElement("div");
                  group.setAttribute("data-hf-motion-blur-group", "hf-mb-" + window._hfMbUid++);
                  group.style.cssText =
                    "position:absolute;left:0;top:0;width:0;height:0;isolation:isolate;pointer-events:none;display:none;";

                  var clones = [];
                  for (var k = 0; k < copies; k++) {
                    var clone = el.cloneNode(true);
                    clone.removeAttribute("id");
                    stripCopyAttrs(clone);
                    clones.push(clone);
                    group.appendChild(clone);
                  }
                  var s = {
                    el: el,
                    group: group,
                    clones: clones,
                    samples: [],
                    perspective: "",
                    watch: null,
                  };

                  // Resolved styles and the parent's perspective are px once read, so a
                  // container-relative element needs them again when its box changes. Per frame
                  // that would walk the whole subtree once per copy; on resize it costs nothing
                  // on a fixed-size render and keeps a live preview honest.
                  function snapshot() {
                    var styles = resolvedStyles(el, []);
                    s.perspective = parentPerspective(el);
                    for (var c = 0; c < clones.length; c++) {
                      paintResolvedStyles(clones[c], styles, { i: 0 });
                      clones[c].style.position = "absolute";
                      clones[c].style.margin = "0";
                      clones[c].style.opacity = alpha;
                      clones[c].style.mixBlendMode = "plus-lighter";
                    }
                  }

                  // Snapshot BEFORE the group enters the page, so a throw in the style walk leaves
                  // nothing behind: the record the rollback needs does not exist until it returns.
                  snapshot();
                  el.parentNode.insertBefore(group, el);
                  if (typeof ResizeObserver === "function") {
                    s.watch = new ResizeObserver(snapshot);
                    s.watch.observe(el);
                  }
                  return s;
                }

                var state = [];
                // Every element this call marked. A throw inside `attachOne` never returns its
                // record, so `state` alone cannot give the marks back.
                var claimed = [];
                try {
                  for (var q = 0; q < targets.length; q++) {
                    var candidate = targets[q];
                    // One group per element, whether a second call names it or one call names it
                    // twice: a second set of copies over the first would double the ink. Marked
                    // BEFORE the copies go in: inserting them runs custom-element reactions
                    // synchronously, and one that registers a timeline re-enters the write trap.
                    if (window._hfMbAttached.has(candidate)) continue;
                    window._hfMbAttached.add(candidate);
                    window._hfMbTimeline.set(candidate, tl);
                    claimed.push(candidate);
                    state.push(attachOne(candidate));
                  }
                } catch (e) {
                  unmark(claimed);
                  discard(state);
                  throw e;
                }
                // Nothing to blur means nothing to seek: a tracker here would run the whole sample
                // loop every frame over an empty set.
                if (state.length === 0) return;

                // One seek loop drives the whole call, so the window is ONE length, and it belongs
                // to the composition of an element this call actually attached.
                var fps = resolveFps(opts.fps, state[0].el);
                for (var d = 1; d < state.length; d++) {
                  if (resolveFps(opts.fps, state[d].el) === fps) continue;
                  var line = "one call cannot blur compositions at different frame rates; using ";
                  console.warn("[motion-blur] " + line + fps, state[d].el);
                  break;
                }

                function readTransform(el) {
                  var cs = getComputedStyle(el);
                  return {
                    css: cs.transform,
                    origin: cs.transformOrigin,
                    opacity: cs.opacity,
                    parsed: parseTransform(cs.transform),
                  };
                }

                var scheduled = false;

                function applyShutter() {
                  var shutterTime = shutterAngle / 360 / fps;
                  if (!(shutterTime > 0)) {
                    state.forEach(function (s) {
                      s.group.style.display = "none";
                    });
                    return;
                  }

                  var t0 = tl.time();
                  var duration = tl.duration();
                  var windowStart = t0 + shutterPhase / 360 / fps;

                  // Sample the real trajectory: seek to each sub-frame time with events
                  // suppressed (so no tween callbacks, including this tracker's, fire),
                  // read the resolved transform, then restore the frame time.
                  try {
                    for (var k = 0; k < copies; k++) {
                      var tk = windowStart + (k / samples) * shutterTime;
                      tl.time(Math.min(duration, Math.max(0, tk)), true);
                      state.forEach(function (s) {
                        s.samples[k] = readTransform(s.el);
                      });
                    }
                  } finally {
                    tl.time(t0, true);
                  }

                  state.forEach(function (s) {
                    var current = readTransform(s.el);
                    var moved = false;
                    for (var i = 0; i < copies; i++) {
                      if (differs(s.samples[i].parsed, current.parsed)) {
                        moved = true;
                        break;
                      }
                    }
                    if (!moved) {
                      s.group.style.display = "none";
                      return;
                    }

                    // The copies are absolutely positioned inside the group, and the group sits at
                    // the origin of the element's own containing block, so the element's offset box
                    // places them. Re-read every frame: a beat is free to move the box itself.
                    var left = s.el.offsetLeft + "px";
                    var top = s.el.offsetTop + "px";
                    var width = s.el.offsetWidth + "px";
                    var height = s.el.offsetHeight + "px";
                    for (var j = 0; j < copies; j++) {
                      var clone = s.clones[j];
                      clone.style.left = left;
                      clone.style.top = top;
                      clone.style.width = width;
                      clone.style.height = height;
                      clone.style.transformOrigin = s.samples[j].origin;
                      clone.style.transform =
                        s.perspective + (s.samples[j].css === "none" ? "" : s.samples[j].css);
                    }
                    // The copies are the element's own ink, so they have to carry its opacity too:
                    // a beat that moves and fades at once would otherwise leave a full-strength
                    // smear behind a vanishing element. It rides the group, not the copies, whose
                    // own opacity is the 1/N shutter weight.
                    s.group.style.opacity = current.opacity;
                    s.group.style.display = "";
                  });
                }

                // tl.eventCallback("onUpdate") is unavailable under the HyperFrames runtime proxy, so a
                // tracker tween's onUpdate fires on every seek. Sampling is deferred to a microtask:
                // seeking GSAP from inside its own render reads stale tween state, while the microtask
                // runs after the seek returns and before the frame is captured or painted.
                var _proxy = { t: 0 };
                try {
                  tl.to(
                    _proxy,
                    {
                      t: 1,
                      duration: Math.max(tl.duration(), 0.1),
                      ease: "none",
                      onUpdate: function () {
                        if (scheduled) return;
                        scheduled = true;
                        Promise.resolve().then(function () {
                          scheduled = false;
                          applyShutter();
                        });
                      },
                    },
                    0,
                  );
                } catch (e) {
                  unmark(claimed);
                  discard(state);
                  throw e;
                }
              };

              // An empty attribute means defaults; anything else is a JSON options object. A value that
              // is not an options object is skipped loudly rather than read as defaults, because a typo
              // in it would otherwise render as a silently unblurred element.
              function sweepOptions(el) {
                var text = (el.getAttribute(SWEEP_ATTR) || "").trim();
                if (text === "") return {};
                var parsed = null;
                try {
                  parsed = JSON.parse(text);
                } catch (e) {
                  return refuse(el, "is not JSON: " + text);
                }
                // `null`, a number and a string all parse. None of them is a set of options.
                if (parsed === null || typeof parsed !== "object" || Array.isArray(parsed)) {
                  return refuse(el, "is not a JSON object: " + text);
                }
                var bad = unknownKey(parsed);
                if (bad !== null) return refuse(el, "names no such option: " + bad);
                var wrong = nonNumber(parsed);
                if (wrong !== null) return refuse(el, "needs a number for " + wrong);
                return parsed;
              }

              // A misspelled key is the likeliest typo in a JSON object, and reading it as
              // defaults is the silent no-op this attribute exists to remove.
              function unknownKey(parsed) {
                for (var key in parsed) {
                  if (OPTION_KEYS.indexOf(key) < 0) return key;
                }
                return null;
              }

              // A key with a value the shutter cannot use is the same silent no-op as a key it does
              // not know: a non-numeric angle hides the smear, a non-numeric phase parks every copy
              // at the timeline's start. JSON gives real numbers, so anything else is a typo.
              function nonNumber(parsed) {
                for (var i = 0; i < OPTION_KEYS.length; i++) {
                  var held = parsed[OPTION_KEYS[i]];
                  if (held === undefined) continue;
                  if (typeof held !== "number" || !Number.isFinite(held)) return OPTION_KEYS[i];
                }
                return null;
              }

              // A throw partway through an attach leaves an element blurred by nothing, so the copies
              // go too, along with the observer that would otherwise keep walking a detached subtree
              // on every resize of an element nothing blurs.
              // The mark is what a second trigger reads, so it is the first thing to give back.
              function unmark(els) {
                for (var i = 0; i < els.length; i++) {
                  window._hfMbAttached.delete(els[i]);
                  window._hfMbTimeline.delete(els[i]);
                }
              }

              function discard(state) {
                for (var i = 0; i < state.length; i++) {
                  var s = state[i];
                  if (s.watch !== null) s.watch.disconnect();
                  if (s.group.parentNode !== null) s.group.parentNode.removeChild(s.group);
                }
              }

              function refuse(el, why) {
                window._hfMbSkipped.add(el);
                console.warn("[motion-blur] " + SWEEP_ATTR + " " + why, el);
                return null;
              }

              // An element belongs to the nearest composition above it, so a sub-composition's
              // targets follow that sub-composition's own timeline.
              function compositionOf(el) {
                var host = el.closest("[data-composition-id]");
                return host ? host.getAttribute("data-composition-id") : null;
              }

              // Anything else registered on the container is somebody else's bookkeeping: a
              // timeline is the thing this snippet can seek and extend.
              function isTimeline(value) {
                return !!value && typeof value.time === "function" && typeof value.to === "function";
              }

              // Attached, or skipped as unparseable. Both are terminal, so a later trigger must not
              // report or attach the element twice.
              function handled(el) {
                return window._hfMbAttached.has(el) || window._hfMbSkipped.has(el);
              }

              // The timeline registered for an element's own composition, or null. Read from the
              // registry rather than taken from whoever wrote it, so every trigger agrees.
              function timelineFor(el) {
                var id = compositionOf(el);
                if (id === null) return null;
                var registry = window.__timelines;
                var found = registry ? registry[id] : null;
                return isTimeline(found) ? found : null;
              }

              // A marked element whose parent is not an Element has no target above it: the parent
              // of a root is the Document, which has no `closest`.
              function nestedInTarget(el) {
                var parent = el.parentNode;
                if (parent === null || typeof parent.closest !== "function") return false;
                return parent.closest(SWEEP_SELECTOR) !== null;
              }

              // One owner of attaching one element. Answers whether the element still needs a trigger.
              function claim(el) {
                var tl = timelineFor(el);
                if (handled(el)) {
                  var owner = window._hfMbTimeline.get(el);
                  // Re-registering a key with a DIFFERENT timeline leaves the copies driven by the one
                  // nobody seeks, which renders sharp and says nothing. Report it rather than guess.
                  var changed = tl !== null && owner !== undefined && owner !== tl;
                  if (changed && !window._hfMbWarned.has(el)) {
                    window._hfMbWarned.add(el);
                    console.warn(
                      "[motion-blur] a second timeline registered for this element; the copies still follow the first",
                      el,
                    );
                  }
                  return true;
                }
                // Its group would be inserted into the live outer element, so the outer target's
                // style replay would walk a subtree its cursor no longer matches.
                if (nestedInTarget(el)) {
                  refuse(el, "cannot blur a target inside another target; blur one of them");
                  return true;
                }
                var opts = sweepOptions(el);
                if (opts === null) return true;
                if (tl === null) return false;
                window.attachMotionBlur(el, tl, opts);
                return true;
              }

              // Returns the elements still waiting for their composition to register a timeline.
              // The trap below runs this INSIDE the author's registration statement, so one bad
              // target must not abort the rest of their composition script.
              function sweep() {
                var pending = [];
                document.querySelectorAll(SWEEP_SELECTOR).forEach(function (el) {
                  try {
                    if (!claim(el)) pending.push(el);
                  } catch (e) {
                    window._hfMbSkipped.add(el);
                    console.warn("[motion-blur] could not blur this element: " + e, el);
                  }
                });
                return pending;
              }

              // Registering a timeline is the moment the author has finished building it, so trapping
              // the write attaches before the renderer captures a frame. A microtask would be too
              // early: it runs before the next `<script>` tag.
              function registrationProxy(container) {
                var proxy = new Proxy(container, {
                  set: function (target, key, value) {
                    target[key] = value;
                    if (typeof key === "string") sweep();
                    return true;
                  },
                });
                window._hfMbProxies.add(proxy);
                return proxy;
              }

              function hookRegistration() {
                var held = window.__timelines;
                Object.defineProperty(window, "__timelines", {
                  configurable: true,
                  enumerable: true,
                  get: function () {
                    return held;
                  },
                  set: function (value) {
                    var container = !!value && typeof value === "object";
                    var fresh = container && !window._hfMbProxies.has(value);
                    held = fresh ? registrationProxy(value) : value;
                    if (fresh) sweep();
                  },
                });
                // A container assigned before this snippet ran is replayed through the setter, so a
                // timeline already registered on it is swept too.
                if (held !== undefined) window.__timelines = held;
              }

              // The trap above cannot see every registration: the runtime owns the registry object,
              // wraps it per sub-composition, and mounts nested compositions asynchronously. So the
              // registry is also POLLED, which needs no cooperation from whoever writes it.
              function poll(ticks) {
                var pending = sweep();
                // The WHOLE budget, every time. Stopping the first tick nothing is pending kills the
                // poll one tick into an ordinary page, which is before a late composition arrives.
                if (ticks > 0) {
                  setTimeout(function () {
                    poll(ticks - 1);
                  }, POLL_MS);
                  return;
                }
                if (pending.length === 0) return;
                var count = pending.length + " element(s) carry " + SWEEP_ATTR;
                console.warn(
                  "[motion-blur] " + count + ", and no composition registered a timeline for them",
                  pending,
                );
              }

              if (!window._hfMbHooked) {
                window._hfMbHooked = true;
                hookRegistration();
                poll(POLL_TICKS);
              }
              /* SHUTTER_SNIPPET_END */
            })();
          </script>
          <script>
            (function () {
              "use strict";

              var root = document.getElementById("root");
              var word = root.querySelector(".ss-word");
              var vars =
                window.__hyperframes && window.__hyperframes.getVariables
                  ? window.__hyperframes.getVariables()
                  : {};

              var text = vars.text == null ? "MOTION" : String(vars.text);
              var accentColors = {
                green: "var(--brand, #71f5a7)",
                blue: "var(--accent, #61a8ff)",
                violet: "var(--accent-2, #b895ff)",
              };
              var accent = Object.prototype.hasOwnProperty.call(accentColors, vars.accent)
                ? vars.accent
                : "green";
              var blurred = vars.blur !== "none";
              var exit = vars.exit === "fade" || vars.exit === "up" ? vars.exit : "none";

              root.style.setProperty("--ss-accent", accentColors[accent]);
              word.textContent = text;

              // One em per character keeps any word inside the box at rest, which is what
              // the slam amplitudes are measured against; the scale punch is meant to
              // overflow and the clip crops it.
              var fittedCqw = Math.min(14, 76 / Math.max(1, Array.from(text).length));
              root.style.setProperty("--ss-font-size", "min(" + fittedCqw.toFixed(3) + "cqw, 26cqh)");

              // Measured best, not defaulted. A bezier fitted to the reference's own bbox
              // centres renders 0.25 dB worse over the clip, because a blurred bbox centre
              // is the shutter window's average rather than the instant. See the header.
              var EASE = "power2.inOut";
              var SLAM_X = 32.1; // cqw, the reference's 617 px on a 1920 px frame
              var SLAM_Y = 30.5; // cqh, its 329 px on a 1080 px frame
              var SLAM = 0.3;
              var TURN = 0.6;
              var TURN_Z = 0.733;
              // Authored start of each beat.
              var CUES_BASE = [0, 1.2, 2.4, 3.7, 4.5, 5.233];
              var BEATS_BASE = CUES_BASE[5] + TURN_Z;
              var OUT_BASE = exit === "none" ? 0 : 0.4;

              var duration = Math.max(0.001, parseFloat(root.dataset.duration || "6"));
              var baseTotal = BEATS_BASE + OUT_BASE;
              var beatScale = duration < baseTotal ? duration / baseTotal : 1;

              var slam = SLAM * beatScale;
              var turn = TURN * beatScale;
              var turnZ = TURN_Z * beatScale;
              var out = OUT_BASE * beatScale;
              // How long each beat runs, in beat order.
              var LENGTHS = [slam * 4, slam * 4, slam * 4, turn, turn, turnZ];

              // An authored cue replaces the rhythm rather than scaling it, so a beat locked
              // to narration lands where the narration does. A missing or unreadable entry
              // keeps its authored start; one that would run its beat past the mount is
              // pulled back to end on the last frame, since past the end it never renders.
              var authored = String(vars.cues == null ? "" : vars.cues)
                .split(",")
                .map(function (part) {
                  return parseFloat(part.trim());
                });
              var cues = CUES_BASE.map(function (base, index) {
                var value = authored[index];
                if (!Number.isFinite(value)) return base * beatScale;
                return Math.min(Math.max(value, 0), Math.max(0, duration - out - LENGTHS[index]));
              });

              var tl = gsap.timeline({ paused: true, defaults: { ease: EASE } });

              // Beat 1 — translate X, out and back twice.
              tl.to(word, { x: SLAM_X + "cqw", duration: slam }, cues[0])
                .to(word, { x: -SLAM_X + "cqw", duration: slam }, cues[0] + slam)
                .to(word, { x: SLAM_X + "cqw", duration: slam }, cues[0] + slam * 2)
                .to(word, { x: 0, duration: slam }, cues[0] + slam * 3);

              // Beat 2 — translate Y, up first.
              tl.to(word, { y: -SLAM_Y + "cqh", duration: slam }, cues[1])
                .to(word, { y: SLAM_Y + "cqh", duration: slam }, cues[1] + slam)
                .to(word, { y: -SLAM_Y + "cqh", duration: slam }, cues[1] + slam * 2)
                .to(word, { y: 0, duration: slam }, cues[1] + slam * 3);

              // Beat 3 — scale punch, up then down then up.
              tl.to(word, { scale: 4.04, duration: slam }, cues[2])
                .to(word, { scale: 0.466, duration: slam }, cues[2] + slam)
                .to(word, { scale: 4.04, duration: slam }, cues[2] + slam * 2)
                .to(word, { scale: 1, duration: slam }, cues[2] + slam * 3);

              // Beats 4 to 6 — one full turn about each axis. A full turn ends where it
              // started, so each is a single tween rather than an out-and-back pair.
              tl.to(word, { rotationX: 360, duration: turn }, cues[3]);
              tl.to(word, { rotationY: 360, duration: turn }, cues[4]);
              tl.to(word, { rotation: 360, duration: turnZ }, cues[5]);

              var beatsEnd = Math.max.apply(
                null,
                cues.map(function (cue, index) {
                  return cue + LENGTHS[index];
                }),
              );
              var outStart = Math.max(beatsEnd, duration - out);

              if (exit !== "none") {
                var leaving = { opacity: 0, duration: out, ease: "power2.in" };
                if (exit === "up") leaving.y = "-12cqh";
                tl.to(word, leaving, outStart);
              }

              // Seeks past the last tween must still reach the blur's tracker, so the
              // timeline runs to the mount's full duration.
              tl.set(document.body, {}, duration);

              // After every tween, before registration: the tracker tween the blur adds
              // needs the timeline's final duration.
              if (blurred) attachMotionBlur(word, tl, { fps: 30 });

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

Tagged `effect` `motion-blur` `shutter` `after-effects` `slam` `animation`.

## Related topics

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