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Spatial Transformations

Description​

Spatial transformations are used to transform a mobject in space. They typically operate as affine transformations to scale, shift, stretch, or rotate the mobject.

Details​

All mobjects to date inherit from TransformableMobject, where these methods live. However, some classes like Text override these transformation functions to provide more sensible defaults (e.g., Rotated text should rotate in space but remain upright by default).

Methods​

  • rotate(angle: float = PI / 4, axis: Vector3 = OUT, about_point: Point3D | None = ORIGIN) -> Self: Rotates the mobject by a specified angle around a given axis and about a specific point. By default, rotates about the 2D origin, which is the center of the canvas.
  • scale(factor: float, about_point: Point3D = ORIGIN) -> Self: Scales the mobject by a given factor about a specified point. The center of the mobject does not change.
  • stretch(factor: float, dim: int) -> Self: Stretches the mobject by a specified factor along a given dimension. The center of the mobject does not change.
  • shift(vector: Vector3) -> Self: Shifts (or translates) the mobject by a specified vector.
  • stretch_to_fit_width(width: float) -> Self: Stretches the mobject to fit a specified width.
  • stretch_to_fit_height(height: float) -> Self: Stretches the mobject to fit a specified height.
  • scale_to_fit_width(width: float) -> Self: Scales the mobject to fit a specified width.
  • scale_to_fit_height(height: float) -> Self: Scales the mobject to fit a specified height.

Examples​

Example 1​

Simple scaling of a square.

from smanim import *

square = Square(color=GRAY)
large_square = Square(color=GRAY).scale(2)
large_square.next_to(square, RIGHT)
canvas.add(square, large_square)
canvas.draw(crop=True, ignore_bg=True)
Example 1

Example 2​

Stretching and rotating a simple number line (which contains vmobjects and text).

from smanim import *

y_axis = NumberLine()
y_axis.stretch(0.5, dim=0)
y_axis.rotate(PI / 8)
y_axis.set_color(GRAY)
canvas.add(y_axis)
canvas.draw(crop=True, ignore_bg=True)
Example 2

Example 3​

Scaling of a group to fit the width of a text description.

from smanim import *

shape_group = Group(Square(z_index=1, color=GRAY), Circle(color=DARK_GRAY).shift(RIGHT * 0.5))
label = Text("""Mobjects take layer precedence based their z_index or when their z_indexes are equal the order they are added to the canvas.
The z_index of a mobject by default is 0.""", color=GRAY)
shape_group.scale_to_fit_width(label.width)
label.next_to(shape_group, UP, LEFT)
canvas.add(shape_group, label)
canvas.draw(crop=True, ignore_bg=True)
Example 3