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hyperframes/skills/hyperframes-animation/rules/svg-path-draw.md
WaterrrForeverandClaude Fable 5 a6a9e2f89e feat(skills): anchored-connector rule + source-traceable visuals doctrine (#3354)
* feat(skills): anchored-connector rule + source-traceable visuals doctrine

Two advisory rules absorbed from a community-skill comparison study
(4-cell sandbox replay vs geekjourneyx/hyperframes-motion-director;
ideas only — no upstream text, the repo is AGPL-3.0):

- Connector lines earn their place: any beam/rail/scan/underline must
  name both anchors and its job (reveal/route/validate) or be cut.
  Lands in motion-principles (composition) + svg-path-draw (constraints).
- Visuals point back to the source: when a video derives from concrete
  material, each frame's key visual should trace to a specific source
  line — real filenames/numbers over stock props. Lands as story-spine
  rule 4; the four SKILL.md index lines that enumerate story-spine's
  rules are synced.

Both are self-checks, not hard gates. lint:skills + skill-mirror green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(skills): regen stale manifest + add emphasize to connector job list

Review 4975048154 follow-ups:
- skills-manifest.json was hashed mid-commit before oxfmt renormalized
  the four SKILL.md tables (lefthook pre-commit runs format and
  skills-manifest in parallel — they raced). Regenerated at head;
  second regen is a no-op.
- The connector rule's job list read literally would cut lines this
  same doctrine prescribes (dividers, hairlines, underline_sweep):
  emphasis was a missing job, not a forbidden one. Added 'emphasize'
  to both motion-principles and svg-path-draw.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-20 14:21:31 +08:00

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name, description, metadata
name description metadata
svg-path-draw Animate SVG paths drawing progressively using stroke-dasharray and stroke-dashoffset.
tags
svg, stroke, draw, path, reveal, icon, vector

SVG Path Draw

Reveals an SVG shape by animating its stroke as if a pen were tracing it. Two stroke properties together: stroke-dasharray = <pathLength> makes the entire path one dash; stroke-dashoffset starts at the path length (dash shifted fully out of view → invisible) and tweens to 0 (fully drawn). The length comes from the DOM API path.getTotalLength() — measured, never guessed.

Works on anything with a stroke: <path>, <circle>, <rect>, <line>, <polyline>, <polygon>, <ellipse>.

Recipe

<!-- inside a standard scene clip -->
<svg class="logo-mark" viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
  <path id="bar-left" d="M 60 40 L 60 160" />
  <path id="bar-right" d="M 140 40 L 140 160" />
  <path id="bar-mid" d="M 60 100 L 140 100" />
</svg>
.logo-mark path {
  fill: none; /* outline-only draw — a fill would appear immediately and ruin the reveal */
  stroke: {accentColor};
  stroke-width: 12;
  stroke-linecap: round; /* softer endpoints */
  stroke-linejoin: round;
}
// Setup: measure each path and set its dash pattern. Real measured geometry, not a magic number.
document.querySelectorAll(".logo-mark path").forEach((p) => {
  const len = p.getTotalLength();
  p.style.strokeDasharray = `${len}`;
  p.style.strokeDashoffset = `${len}`;
});

// Stagger draws so the eye reads continuous motion — each segment starts at
// ~70-80% of the previous segment's duration, before it finishes.
tl.to(
  "#bar-left",
  { strokeDashoffset: 0, duration: SEGMENT_DRAW_DUR, ease: "power2.out" },
  SEG_1_START,
);
tl.to(
  "#bar-right",
  { strokeDashoffset: 0, duration: SEGMENT_DRAW_DUR, ease: "power2.out" },
  SEG_2_START,
);
tl.to(
  "#bar-mid",
  { strokeDashoffset: 0, duration: FINAL_SEGMENT_DUR, ease: "power2.out" },
  SEG_3_START,
);

// Companion wordmark fades in only after the last stroke settles.
tl.to(
  ".brand-line",
  { opacity: 1, duration: BRAND_FADE_DUR, ease: "power1.out" },
  BRAND_FADE_START,
);

Variations

  • Ring starting at 12 o'clock<circle> / <rect> strokes start at 3 o'clock by default; rotate the element -90deg so a progress ring draws from the top:
<circle
  cx="100"
  cy="100"
  r="60"
  id="ring"
  style="transform-origin: 100px 100px; transform: rotate(-90deg)"
/>
  • Linear (constant-speed) drawease: "none" for a steady-rate "real pen" trace.
  • Draw then fill — for filled shapes, tween fillOpacity: 0 → 1 AFTER the stroke completes (requires fill-opacity: 0 initially and a real fill in CSS):
tl.to(
  "#path",
  { strokeDashoffset: 0, duration: SEGMENT_DRAW_DUR, ease: "power2.out" },
  SEG_1_START,
);
tl.to(
  "#path",
  { fillOpacity: 1, duration: FILL_FADE_DUR, ease: "power1.out" },
  SEG_1_START + SEGMENT_DRAW_DUR,
);

Values

token range notes
SEGMENT_DRAW_DUR 0.30.8s fast snap vs deliberate pen trace; >~1s feels sluggish for a logo reveal
FINAL_SEGMENT_DUR 6080% of SEGMENT_DRAW_DUR proportional to segment length — a short connector at full duration reads slower than its siblings
SEG_N_START previous start + 7080% of its duration reads as continuous motion, not N isolated animations
SEG_1_START 00.4s a small ~0.2s lead-in lets the viewer settle before motion
BRAND_FADE_START ≥ last stroke end (+ ~0.2s beat) earlier and the wordmark competes with the draw
BRAND_FADE_DUR 0.30.8s snap (urgent) vs glide (premium)

Ease families are discrete choices: stroke draws use power2.out (a hand lifting at end of stroke) or none for constant speed — never back.out / elastic.out (pens don't bounce). Fades use power1.out.

Critical Constraints

  • fill: none for outline-only draws — otherwise the fill appears immediately.
  • Dasharray/dashoffset = the measured getTotalLength(), set at setup; requires the SVG in the DOM (inline SVG is fine; a loaded <image> SVG is not).
  • Complex paths: if getTotalLength() looks wrong, overestimate slightly (len * 1.05) — too large is invisible at animation start; too small clips the end.
  • Stagger multi-path draws at ~7080% of the previous segment's duration.
  • A drawn line must land on something. When the path is a connector (rail, beam, underline, callout) rather than a shape, both endpoints must sit on real elements and the draw must do a job — reveal, route, validate, or emphasize. A stroke that only decorates empty space reads as filler; attach it or cut it.

See also

svg-icon-enrichment (internal parts animate after the outline draws) · counting-dynamic-scale (stroke draws an icon while a number counts up) · hacker-flip-3d (logo draws, wordmark decodes beneath).