Manim Scene Craft

Use before writing a scene or changing render, font, arrow, or layout constants. Skip this skill for changelog, documentation, or non-visual code.

Core invariants

The five rules below are non-negotiable. Detailed rationale + code lives in rules/.

1. Single text entry point. All Text(...) calls go through _make_text so the EN/KO font + weight=NORMAL lock can't slip. Raw Text( is a regression. See rules/scene-skeleton.md.
2. Padding safe zones. Box + header + outline lines arrange as a single VGroup(...).arrange(DOWN, buff=...).next_to(body.get_top(), DOWN, buff=...) — never as separate move_to calls. See rules/safe-zones.md.
3. Section transitions in one play. _set_section_title bundles FadeOut(prior title) + FadeOut(prior content) + FadeIn(new title) into a single self.play(...) so transitions don't show a 0.5–0.8 s empty frame. See rules/scene-skeleton.md.
4. Arrow labels perpendicular. Arrow labels offset ≥ 0.5 perpendicular to the arrow direction. UP * 0.25 from center is forbidden — near-vertical dashed lines slice through the glyphs. See rules/safe-zones.md.
5. Layout ratchet on every box. Every new container + text pair gets a Site(...) entry in verify_hero_layout.py. Run --update-baseline locally, commit layout_baseline.json. See rules/layout-ratchet.md.

File map

File	Purpose
rules/scene-skeleton.md	Imports, palette, _t, _make_text, _set_section_title, Bit construction order
rules/safe-zones.md	Padding rules, arrow geometry, canvas edge limits, _dashed_arrow_with_head
rules/multilingual-render.md	EN/KO lang switch, render commands, output paths, ~/Downloads/ copy
rules/layout-ratchet.md	verify_hero_layout.py SITES + baseline JSON + CI step
references/data-sot.md	Which markdown SoT each scene reads from + parity rules
references/pre-pr-checklist.md	5-item grep checklist before pushing
references/external-oss.md	adithya-s-k/manim_skill (mobject API reference) + other OSS, with stars / last-push verified 2026-05-21

Pre-flight

uv add manim --dev && uv sync
brew install pkg-config cmake                  # macOS, for pycairo
brew install --cask font-pretendard            # KO font

uv run python scripts/visualizations/verify_hero_layout.py --static-check

--static-check validates the committed layout_baseline.json without importing Manim — fast CI gate.

Standard render

uv run manim -qh -o <Name>-EN scripts/visualizations/<file>.py <SceneClass>
GEODE_HERO_LANG=ko uv run manim -qh -o <Name>-KO scripts/visualizations/<file>.py <SceneClass>
cp media/videos/<file>/1080p60/<Name>-{EN,KO}.mp4 ~/Downloads/

After render, run the post-mortem audit workflow in [[viz-frame-audit]].

Workflow differentiator

adithya-s-k/manim_skill (874★) is the recommended external reference for the general ManimCE API. This skill layers GEODE-specific patterns on top that the external skill does not cover: EN/KO lang switch, Helvetica Neue + Pretendard pairing with weight=NORMAL lock, Anthropic-style 6-color palette, verify_hero_layout.py ratchet, _dashed_arrow_with_head stage-coupled head tinting, and the 12+ defect catalogue from four validated scenes.

The defect catalogue (filewalk × 5, hero × 7) lives in [[viz-frame-audit]]'s references/defect-catalogue.md.