Quick Start

This guide walks through the main parts of manim_extensions and shows how to use them in a Manim scene.

Installation

Install the latest stable release from PyPI:

pip install manim_extensions

The only runtime dependency is manim.

If you want to use ChineseMathTex, make sure xelatex and the xeCJK LaTeX package are available on your system.

Basic import

Import the public API directly from manim_extensions:

from manim_extensions import (
    ChineseMathTex,
    LabelDot,
    MathTexLine,
    MathTexBrace,
    MathTexDoublearrow,
    ExtendedLine,
    PerpendicularLine,
    PerpendicularSign,
    CircleInt,
    LineCircleInt,
    LineInt,
    LineArcInt,
    TangentPoint,
    VisDrawArc,
    TypeWriter,
)

Annotated mobjects

CircleInt() and LabelDot are useful when you want to label key points or show intersections:

Example: QuickstartAnnotatedScene

../_images/QuickstartAnnotatedScene-1.png 
from manim import *
from manim_extensions import CircleInt, LabelDot

class QuickstartAnnotatedScene(Scene):
    def construct(self):
        c1 = Circle(radius=2, color=BLUE).shift(LEFT)
        c2 = Circle(radius=2, color=GREEN).shift(RIGHT)
        pts = CircleInt(c1, c2)

        self.add(c1, c2)
        if pts:
            for p in pts:
                self.add(LabelDot("P", p, label_pos=UP, buff=0.15))

from manim import *
from manim_extensions import CircleInt, LabelDot

class QuickstartAnnotatedScene(Scene):
    def construct(self):
        c1 = Circle(radius=2, color=BLUE).shift(LEFT)
        c2 = Circle(radius=2, color=GREEN).shift(RIGHT)
        pts = CircleInt(c1, c2)

        self.add(c1, c2)
        if pts:
            for p in pts:
                self.add(LabelDot("P", p, label_pos=UP, buff=0.15))

Geometry helpers

The geometry module provides analytic-geometry functions that return plain points, so you can use them with any Manim mobject:

Example: QuickstartGeometry

../_images/QuickstartGeometry-1.png 
from manim import *
from manim_extensions import LineInt, PerpendicularLine, LabelDot

class QuickstartGeometry(Scene):
    def construct(self):
        line = Line(LEFT * 3, RIGHT * 3)
        perp = PerpendicularLine(UP * 1.5, line, color=YELLOW)
        self.add(line, perp)

from manim import *
from manim_extensions import LineInt, PerpendicularLine, LabelDot

class QuickstartGeometry(Scene):
    def construct(self):
        line = Line(LEFT * 3, RIGHT * 3)
        perp = PerpendicularLine(UP * 1.5, line, color=YELLOW)
        self.add(line, perp)

Animations

VisDrawArc() draws an arc while showing a moving radius, and TypeWriter reveals Text character by character:

Example: QuickstartAnimations 

from manim import *
from manim_extensions import VisDrawArc, TypeWriter

class QuickstartAnimations(Scene):
    def construct(self):
        arc = Arc(start_angle=0, angle=PI, radius=2, color=YELLOW)
        VisDrawArc(self, arc, axis=OUT, run_time=2)

        text = Text("Hello Extensions").shift(DOWN * 2)
        self.play(TypeWriter(text, interval=0.1))

from manim import *
from manim_extensions import VisDrawArc, TypeWriter

class QuickstartAnimations(Scene):
    def construct(self):
        arc = Arc(start_angle=0, angle=PI, radius=2, color=YELLOW)
        VisDrawArc(self, arc, axis=OUT, run_time=2)

        text = Text("Hello Extensions").shift(DOWN * 2)
        self.play(TypeWriter(text, interval=0.1))

Bundled plugins

manim_extensions also ships three ready-to-use plugins. Each is documented in the Reference Manual section:

  • GearBox – involute gears and gear trains.

  • Compass – compass, ruler, and pencil animations.

  • MindMap – mind maps, timelines, and catalog trees.

For example, a gear pair can be created with:

Example: QuickstartGear 

from manim import *
from manim_extensions.gearbox import Gear

class QuickstartGear(Scene):
    def construct(self):
        gear1 = Gear(15, stroke_opacity=0, fill_color=WHITE, fill_opacity=1)
        gear2 = Gear(25, stroke_opacity=0, fill_color=RED, fill_opacity=1)
        gear1.shift(-gear1.rp * 1.5 * RIGHT)
        gear2.mesh_to(gear1)

        self.add(gear1, gear2)
        self.play(
            Rotate(gear1, gear1.pitch_angle, rate_func=linear),
            Rotate(gear2, -gear2.pitch_angle, rate_func=linear),
            run_time=4,
        )

from manim import *
from manim_extensions.gearbox import Gear

class QuickstartGear(Scene):
    def construct(self):
        gear1 = Gear(15, stroke_opacity=0, fill_color=WHITE, fill_opacity=1)
        gear2 = Gear(25, stroke_opacity=0, fill_color=RED, fill_opacity=1)
        gear1.shift(-gear1.rp * 1.5 * RIGHT)
        gear2.mesh_to(gear1)

        self.add(gear1, gear2)
        self.play(
            Rotate(gear1, gear1.pitch_angle, rate_func=linear),
            Rotate(gear2, -gear2.pitch_angle, rate_func=linear),
            run_time=4,
        )

See GearBox for more details.

Next steps