3b1b-style-animation

使用时机

使用 Manim（ManimCE）创建数学动画、可视化内容或教育视频时，请使用此技能。

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快速参考（核心模式）

颜色

BG = "#1c1c1c"           # Background (MUST use)
BLUE = "#3b82f6"         # Primary, nodes
YELLOW = "#fbbf24"       # Highlights, emphasis
GREEN = "#22c55e"        # Success, done, positive
RED = "#ef4444"          # Error, negative
GRAY = "#9ca3af"         # Inactive, labels

场景模板

from manim import *

class MyScene(Scene):
    def construct(self):
        self.camera.background_color = "#1c1c1c"
        # Your code here
        self.wait(2)  # End padding

音频同步场景（StrictSync）

TIMING = {
    "01": {"start": 0, "end": 5.5},
    "02": {"start": 5.5, "end": 10.0},
}

class SyncedScene(Scene):
    def construct(self):
        self.camera.background_color = "#1c1c1c"
        for seg_id in sorted(TIMING.keys()):
            method = getattr(self, f"seg_{seg_id}", None)
            if method:
                self._run(seg_id, method)
        self.wait(2)

    def _run(self, seg_id, method):
        t = TIMING[seg_id]
        target = t["end"] - t["start"]
        start = self.renderer.time
        method()
        elapsed = self.renderer.time - start
        if elapsed < target:
            self.wait(target - elapsed)

    def seg_01(self):
        pass  # Your animation

动画模式

# Cascading appear
self.play(LaggedStartMap(FadeIn, VGroup(*items), lag_ratio=0.15), run_time=1)

# Highlight
self.play(Flash(mob, color=YELLOW, line_length=0.2), run_time=0.3)
self.play(Indicate(mob, color=YELLOW), run_time=0.5)

# Transform text
self.play(TransformMatchingStrings(old_text, new_text), run_time=0.5)

# Coordinated (not sequential)
self.play(FadeIn(a), Create(b), Write(c), run_time=1)  # Good
# self.play(FadeIn(a)); self.play(Create(b))  # Bad

布局

# Screen zones
title.to_edge(UP, buff=0.5)
content.move_to(ORIGIN)
info.to_edge(DOWN, buff=0.8)
sidebar.to_edge(RIGHT, buff=1.0)

# Spacing constants
NODE_GAP = 1.5        # Minimum between nodes
EDGE_LABEL_OFFSET = 0.22  # Perpendicular to edge

# Edge label placement
mid = line.get_center()
direction = end - start
perp = np.array([-direction[1], direction[0], 0])
perp = perp / np.linalg.norm(perp) * 0.22
label.move_to(mid + perp)

图形创建模式

self.node_to_circle = {}  # Dictionary mapping
for name, pos in positions.items():
    circle = Circle(radius=0.3, color=BLUE, fill_opacity=0.5, stroke_width=2)
    circle.move_to(pos)
    self.node_to_circle[name] = circle

教学法（3b1b 风格）

1. HOOK: Pose interesting question
2. INTUITION: Visual understanding (NO formulas yet)
3. STEP-BY-STEP: Concrete example with numbers
4. FORMALIZATION: NOW introduce formula/name

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规则（详细参考）

设置与基础

• rules/manim-setup.md - 安装
• rules/scene-basics.md - 场景结构
• rules/color-scheme.md - 完整配色方案

动画

• rules/animation-patterns.md - LaggedStartMap、状态保存与恢复
• rules/text-transforms.md - TransformMatchingStrings
• rules/updaters.md - 用于动态运动的 add_updater
• rules/seamless-transitions.md - 平滑过渡

布局与视觉效果

• rules/layout-spacing.md - 间距、屏幕区域
• rules/mobject-grouping.md - VGroup 组织方式
• rules/visual-quality.md - 质量检查
• rules/camera-work.md - MovingCameraScene

内容类型

• rules/equations.md - LaTeX、MathTex
• rules/graphs.md - 函数绘图
• rules/3d-surfaces.md - ThreeDScene

音频与同步

• rules/audio-sync.md - 音画同步
• rules/strict-sync.md - StrictSyncScene

理念

• rules/pedagogy.md - 先讲直觉，再讲形式化

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必须 / 禁止

必须

• 使用 #1c1c1c 作为背景
• 使用 LaggedStartMap 实现级联效果
• 用 VGroup + 字典对相关元素分组
• 以 self.wait(2) 结束，留出缓冲时间
• 保持 NODE_GAP >= 1.5
• 将边标签垂直于边放置

禁止

• 使用纯黑色（#000000）背景
• 通过单独调用 play() 逐个为元素制作动画
• 将节点放得过近（间距 < 1.5 个单位）
• 尚未建立直觉就展示公式
• 在没有 wait() 的情况下结束 play()