Mobjects Reference
Everything visible on screen is a Mobject. They have position, color, opacity, and can be animated.
Text
`python
title = Text("Hello World", font_size=48, color=BLUE)
eq = MathTex(r"E = mc^2", font_size=40)
Multi-part (for selective coloring)
eq = MathTex(r"a^2", r"+", r"b^2", r"=", r"c^2")
eq[0].set_color(RED)
eq[4].set_color(BLUE)
Mixed text and math
t = Tex(r"The area is $\pi r^2$", font_size=36)
Styled markup
t = MarkupText('Blue text', font_size=30)
`
Always use raw strings (r"") for any string with backslashes.
Shapes
`python
circle = Circle(radius=1, color=BLUE, fill_opacity=0.5)
square = Square(side_length=2, color=RED)
rect = Rectangle(width=4, height=2, color=GREEN)
dot = Dot(point=ORIGIN, radius=0.08, color=YELLOW)
line = Line(LEFT 2, RIGHT 2, color=WHITE)
arrow = Arrow(LEFT, RIGHT, color=ORANGE)
rrect = RoundedRectangle(corner_radius=0.3, width=4, height=2)
brace = Brace(rect, DOWN, color=YELLOW)
`
Polygons and Arcs
`python
Arbitrary polygon from vertices
poly = Polygon(LEFT, UP * 2, RIGHT, color=GREEN, fill_opacity=0.3)
Regular n-sided polygon
hexagon = RegularPolygon(n=6, color=TEAL, fill_opacity=0.4)
Triangle (shorthand for RegularPolygon(n=3))
tri = Triangle(color=YELLOW, fill_opacity=0.5)
Arc (portion of a circle)
arc = Arc(radius=2, start_angle=0, angle=PI / 2, color=BLUE)
Arc between two points
arc_between = ArcBetweenPoints(LEFT 2, RIGHT 2, angle=TAU / 4, color=RED)
Curved arrow (arc with tip)
curved_arrow = CurvedArrow(LEFT 2, RIGHT 2, color=ORANGE)
`
Sectors and Annuli
`python
Sector (pie slice)
sector = Sector(outer_radius=2, start_angle=0, angle=PI / 3, fill_opacity=0.7, color=BLUE)
Annulus (ring)
ring = Annulus(inner_radius=1, outer_radius=2, fill_opacity=0.5, color=GREEN)
Annular sector (partial ring)
partial_ring = AnnularSector(
inner_radius=1, outer_radius=2,
angle=PI / 2, start_angle=0,
fill_opacity=0.7, color=TEAL
)
Cutout (punch holes in a shape)
background = Square(side_length=4, fill_opacity=1, color=BLUE)
hole = Circle(radius=0.5)
cutout = Cutout(background, hole, fill_opacity=1, color=BLUE)
`
Use cases: pie charts, ring progress indicators, Venn diagrams with arcs, geometric proofs.
Positioning
`python
mob.move_to(ORIGIN) # center
mob.move_to(UP * 2 + RIGHT) # relative
label.next_to(circle, DOWN, buff=0.3) # next to another
title.to_edge(UP, buff=0.5) # screen edge (buff >= 0.5!)
mob.to_corner(UL, buff=0.5) # corner
`
VGroup vs Group
VGroup is for collections of shapes (VMobjects only — Circle, Square, Arrow, Line, MathTex):
`python
shapes = VGroup(circle, square, arrow)
shapes.arrange(DOWN, buff=0.5)
shapes.set_color(BLUE)
`
Group is for mixed collections (Text + shapes, or any Mobject types):
`python
Text objects are Mobjects, not VMobjects — use Group when mixing
labeled_shape = Group(circle, Text("Label").next_to(circle, DOWN))
labeled_shape.move_to(ORIGIN)
FadeOut everything on screen (may contain mixed types)
self.play(FadeOut(Group(*self.mobjects)))
`
Rule: if your group contains any Text() objects, use Group, not VGroup. VGroup will raise a TypeError on Manim CE v0.20+. MathTex and Tex are VMobjects and work with VGroup.
Both support arrange(), arrange_in_grid(), set_opacity(), shift(), scale(), move_to().
Styling
`python
mob.set_color(BLUE)
mob.set_fill(RED, opacity=0.5)
mob.set_stroke(WHITE, width=2)
mob.set_opacity(0.4)
mob.set_z_index(1) # layering
`
Specialized Mobjects
`python
nl = NumberLine(x_range=[-3, 3, 1], length=8, include_numbers=True)
table = Table([["A", "B"], ["C", "D"]], row_labels=[Text("R1"), Text("R2")])
code = Code("example.py", tab_width=4, font_size=20, language="python")
highlight = SurroundingRectangle(target, color=YELLOW, buff=0.2)
bg = BackgroundRectangle(equation, fill_opacity=0.7, buff=0.2)
`
Custom Mobjects
`python
class NetworkNode(Group):
def __init__(self, label_text, color=BLUE, **kwargs):
super().__init__(**kwargs)
self.circle = Circle(radius=0.4, color=color, fill_opacity=0.3)
self.label = Text(label_text, font_size=20).move_to(self.circle)
self.add(self.circle, self.label)
`
Matrix Mobjects
Display matrices as grids of numbers or mobjects:
`python
Integer matrix
m = IntegerMatrix([[1, 2], [3, 4]])
Decimal matrix (control decimal places)
m = DecimalMatrix([[1.5, 2.7], [3.1, 4.9]], element_to_mobject_config={"num_decimal_places": 2})
Mobject matrix (any mobject in each cell)
m = MobjectMatrix([
[MathTex(r"\pi"), MathTex(r"e")],
[MathTex(r"\phi"), MathTex(r"\tau")]
])
Bracket types: "(" "[" "|" or "\\{"
m = IntegerMatrix([[1, 0], [0, 1]], left_bracket="[", right_bracket="]")
`
Use cases: linear algebra, transformation matrices, system-of-equations coefficient display.
Constants
Directions: UP, DOWN, LEFT, RIGHT, ORIGIN, UL, UR, DL, DR
Colors: RED, BLUE, GREEN, YELLOW, WHITE, GRAY, ORANGE, PINK, PURPLE, TEAL, GOLD
Frame: config.frame_width = 14.222, config.frame_height = 8.0
SVGMobject — Import SVG Files
`python
logo = SVGMobject("path/to/logo.svg")
logo.set_color(WHITE).scale(0.5).to_corner(UR)
self.play(FadeIn(logo))
SVG submobjects are individually animatable
for part in logo.submobjects:
self.play(part.animate.set_color(random_color()))
`
ImageMobject — Display Images
`python
img = ImageMobject("screenshot.png")
img.set_height(3).to_edge(RIGHT)
self.play(FadeIn(img))
`
Note: images cannot be animated with .animate (they're raster, not vector). Use FadeIn/FadeOut and shift/scale only.
Variable — Auto-Updating Display
`python
var = Variable(0, Text("x"), num_decimal_places=2)
var.move_to(ORIGIN)
self.add(var)
Animate the value
self.play(var.tracker.animate.set_value(5), run_time=2)
Display auto-updates: "x = 5.00"
`
Cleaner than manual DecimalNumber + add_updater for simple labeled-value displays.
BulletedList
`python
bullets = BulletedList(
"First key point",
"Second important fact",
"Third conclusion",
font_size=28
)
bullets.to_edge(LEFT, buff=1.0)
self.play(Write(bullets))
Highlight individual items
self.play(bullets[1].animate.set_color(YELLOW))
`
DashedLine and Angle Markers
`python
Dashed line (asymptotes, construction lines)
dashed = DashedLine(LEFT 3, RIGHT 3, color=SUBTLE, dash_length=0.15)
Angle marker between two lines
line1 = Line(ORIGIN, RIGHT * 2)
line2 = Line(ORIGIN, UP * 2 + RIGHT)
angle = Angle(line1, line2, radius=0.5, color=YELLOW)
angle_label = angle.get_value() # returns the angle in radians
Right angle marker
right_angle = RightAngle(line1, Line(ORIGIN, UP * 2), length=0.3, color=WHITE)
`
Boolean Operations (CSG)
Combine, subtract, or intersect 2D shapes:
`python
circle = Circle(radius=1.5, color=BLUE, fill_opacity=0.5).shift(LEFT * 0.5)
square = Square(side_length=2, color=RED, fill_opacity=0.5).shift(RIGHT * 0.5)
Union, Intersection, Difference, Exclusion
union = Union(circle, square, color=GREEN, fill_opacity=0.5)
intersect = Intersection(circle, square, color=YELLOW, fill_opacity=0.5)
diff = Difference(circle, square, color=PURPLE, fill_opacity=0.5)
exclude = Exclusion(circle, square, color=ORANGE, fill_opacity=0.5)
`
Use cases: Venn diagrams, set theory, geometric proofs, area calculations.
LabeledArrow / LabeledLine
`python
Arrow with built-in label (auto-positioned)
arr = LabeledArrow(Text("force", font_size=18), start=LEFT, end=RIGHT, color=RED)
Line with label
line = LabeledLine(Text("d = 5m", font_size=18), start=LEFT 2, end=RIGHT 2)
`
Auto-handles label positioning — cleaner than manual Arrow + Text().next_to().
Text Color/Font/Style Per-Substring (t2c, t2f, t2s, t2w)
`python
Color specific words (t2c = text-to-color)
text = Text(
"Gradient descent minimizes the loss function",
t2c={"Gradient descent": BLUE, "loss function": RED}
)
Different fonts per word (t2f = text-to-font)
text = Text(
"Use Menlo for code and Inter for prose",
t2f={"Menlo": "Menlo", "Inter": "Inter"}
)
Italic/slant per word (t2s = text-to-slant)
text = Text("Normal and italic text", t2s={"italic": ITALIC})
Bold per word (t2w = text-to-weight)
text = Text("Normal and bold text", t2w={"bold": BOLD})
`
These are much cleaner than creating separate Text objects and grouping them.
Backstroke for Readability Over Backgrounds
When text overlaps other content (graphs, diagrams, images), add a dark stroke behind it:
`python
CE syntax:
label.set_stroke(BLACK, width=5, background=True)
Apply to a group
for mob in labels:
mob.set_stroke(BLACK, width=4, background=True)
`
This is how 3Blue1Brown keeps text readable over complex backgrounds without using BackgroundRectangle.
Complex Function Transforms
Apply complex functions to entire mobjects — transforms the plane:
`python
c_grid = ComplexPlane()
moving_grid = c_grid.copy()
moving_grid.prepare_for_nonlinear_transform() # adds more sample points for smooth deformation
self.play(
moving_grid.animate.apply_complex_function(lambda z: z**2),
run_time=5,
)
Also works with R3->R3 functions:
self.play(grid.animate.apply_function(
lambda p: [p[0] + 0.5 math.sin(p[1]), p[1] + 0.5 math.sin(p[0]), p[2]]
), run_time=5)
`
Critical: Call prepare_for_nonlinear_transform() before applying nonlinear functions — without it, the grid has too few sample points and the deformation looks jagged.