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Mobjects Reference ​

Complete reference for mathematical objects (Mobjects) in Fluxion.

Introduction ​

Mobjects (Mathematical Objects) are the fundamental building blocks of Fluxion animations. Everything you see on screen is a mobject.

Base Classes ​

Mobject ​

The base class for all mobjects.

python
class Mobject:
    def __init__(self, **kwargs):
        pass

VMobject ​

Vector-based mobjects (most common).

python
class VMobject(Mobject):
    pass

Basic Shapes ​

Circle ​

python
Circle(radius=1.0, color=WHITE, **kwargs)

Example:

python
circle = Circle(radius=2, color=BLUE)
circle.set_fill(BLUE, opacity=0.5)

Circle Example

Square ​

python
Square(side_length=2.0, color=WHITE, **kwargs)

Rectangle ​

python
Rectangle(width=4.0, height=2.0, **kwargs)

Triangle ​

python
Triangle(**kwargs)

Polygon ​

python
Polygon(*vertices, **kwargs)

Example:

python
pentagon = Polygon(
    UP, UR, DR, DL, UL,
    color=GREEN
)

Lines and Arrows ​

Line ​

python
Line(start=LEFT, end=RIGHT, **kwargs)

Arrow ​

python
Arrow(start=ORIGIN, end=RIGHT, **kwargs)

Vector ​

python
Vector(direction=RIGHT, **kwargs)

DashedLine ​

python
DashedLine(start=LEFT, end=RIGHT, **kwargs)

Advanced Shapes ​

Ellipse ​

python
Ellipse(width=2.0, height=1.0, **kwargs)

Annulus ​

python
Annulus(inner_radius=1, outer_radius=2, **kwargs)

Arc ​

python
Arc(radius=1.0, start_angle=0, angle=TAU/4, **kwargs)

Sector ​

python
Sector(outer_radius=1, inner_radius=0, **kwargs)

Text Mobjects ​

Text ​

python
Text(text, font="Arial", font_size=48, **kwargs)

Example:

python
title = Text("Hello Fluxion!", font="Arial", font_size=60)
title.set_color(BLUE)

MathTex ​

LaTeX mathematical expressions:

python
MathTex(tex_string, **kwargs)

Example:

python
formula = MathTex(r"E = mc^2")
equation = MathTex(
    r"\int_{-\infty}^{\infty} e^{-x^2} dx = \sqrt{\pi}"
)

Tex ​

General LaTeX text:

python
Tex(tex_string, **kwargs)

3D Mobjects ​

Sphere ​

python
Sphere(radius=1, **kwargs)

Cube ​

python
Cube(side_length=2, **kwargs)

Cylinder ​

python
Cylinder(radius=1, height=2, **kwargs)

Cone ​

python
Cone(base_radius=1, height=2, **kwargs)

Mobject Methods ​

Positioning ​

python
# Move to position
mobject.move_to(ORIGIN)
mobject.move_to(UP * 2 + RIGHT * 3)

# Shift by vector
mobject.shift(LEFT * 2)

# Align to edge
mobject.to_edge(UP)
mobject.to_corner(UR)

# Position relative to another
mobject.next_to(other, RIGHT, buff=0.5)

Scaling ​

python
# Scale uniformly
mobject.scale(2)

# Scale on specific axis
mobject.scale(2, axis=0)  # X-axis

# Stretch
mobject.stretch(2, 0)  # Stretch horizontally

Rotation ​

python
# Rotate around origin
mobject.rotate(PI / 4)

# Rotate around point
mobject.rotate(PI / 4, about_point=ORIGIN)

# Rotate around axis
mobject.rotate(PI / 4, axis=OUT)

Colors and Styling ​

python
# Set color
mobject.set_color(BLUE)
mobject.set_color_by_gradient(BLUE, GREEN)

# Set fill
mobject.set_fill(RED, opacity=0.5)

# Set stroke
mobject.set_stroke(WHITE, width=4)

# Set opacity
mobject.set_opacity(0.5)

Alignment ​

python
# Align to another mobject
mobject.align_to(other, UP)
mobject.align_to(other, LEFT)

# Center
mobject.center()

Grouping ​

VGroup ​

Group multiple mobjects:

python
group = VGroup(circle, square, triangle)
group.arrange(RIGHT, buff=1)

Methods:

python
# Add to group
group.add(mobject)

# Remove from group
group.remove(mobject)

# Arrange
group.arrange(direction=RIGHT, buff=0.5)
group.arrange_in_grid(rows=2, cols=3)

Custom Mobjects ​

Create your own:

python
class CustomShape(VMobject):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.set_points_as_corners([
            UP, RIGHT, DOWN, LEFT, UP
        ])
        self.set_fill(BLUE, opacity=0.5)

See Also ​

Released under the MIT License.

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