"""Animations related to rotation."""
from __future__ import annotations
__all__ = ["Rotating", "Rotate"]
from collections.abc import Callable
from typing import TYPE_CHECKING, Any
from ..animation.animation import Animation
from ..animation.transform import Transform
from ..constants import OUT, PI, TAU
from ..utils.rate_functions import linear
if TYPE_CHECKING:
from ..mobject.mobject import Mobject
from ..mobject.opengl.opengl_mobject import OpenGLMobject
from ..typing import Point3DLike, Vector3DLike
[docs]
class Rotating(Animation):
"""Animation that rotates a Mobject.
Parameters
----------
mobject
The mobject to be rotated.
angle
The rotation angle in radians. Predefined constants such as ``DEGREES``
can also be used to specify the angle in degrees.
axis
The rotation axis as a numpy vector.
about_point
The rotation center.
about_edge
If ``about_point`` is ``None``, this argument specifies
the direction of the bounding box point to be taken as
the rotation center.
run_time
The duration of the animation in seconds.
rate_func
The function defining the animation progress based on the relative
runtime (see :mod:`~.rate_functions`) .
**kwargs
Additional keyword arguments passed to :class:`~.Animation`.
Examples
--------
.. manim:: RotatingDemo
class RotatingDemo(Scene):
def construct(self):
circle = Circle(radius=1, color=BLUE)
line = Line(start=ORIGIN, end=RIGHT)
arrow = Arrow(start=ORIGIN, end=RIGHT, buff=0, color=GOLD)
vg = VGroup(circle,line,arrow)
self.add(vg)
anim_kw = {"about_point": arrow.get_start(), "run_time": 1}
self.play(Rotating(arrow, 180*DEGREES, **anim_kw))
self.play(Rotating(arrow, PI, **anim_kw))
self.play(Rotating(vg, PI, about_point=RIGHT))
self.play(Rotating(vg, PI, axis=UP, about_point=ORIGIN))
self.play(Rotating(vg, PI, axis=RIGHT, about_edge=UP))
self.play(vg.animate.move_to(ORIGIN))
.. manim:: RotatingDifferentAxis
class RotatingDifferentAxis(ThreeDScene):
def construct(self):
axes = ThreeDAxes()
cube = Cube()
arrow2d = Arrow(start=[0, -1.2, 1], end=[0, 1.2, 1], color=YELLOW_E)
cube_group = VGroup(cube,arrow2d)
self.set_camera_orientation(gamma=0, phi=40*DEGREES, theta=40*DEGREES)
self.add(axes, cube_group)
play_kw = {"run_time": 1.5}
self.play(Rotating(cube_group, PI), **play_kw)
self.play(Rotating(cube_group, PI, axis=UP), **play_kw)
self.play(Rotating(cube_group, 180*DEGREES, axis=RIGHT), **play_kw)
self.wait(0.5)
See also
--------
:class:`~.Rotate`, :meth:`~.Mobject.rotate`
"""
def __init__(
self,
mobject: Mobject,
angle: float = TAU,
axis: Vector3DLike = OUT,
about_point: Point3DLike | None = None,
about_edge: Vector3DLike | None = None,
run_time: float = 5,
rate_func: Callable[[float], float] = linear,
**kwargs: Any,
) -> None:
self.angle = angle
self.axis = axis
self.about_point = about_point
self.about_edge = about_edge
super().__init__(mobject, run_time=run_time, rate_func=rate_func, **kwargs)
[docs]
def interpolate_mobject(self, alpha: float) -> None:
self.mobject.become(self.starting_mobject)
self.mobject.rotate(
self.rate_func(alpha) * self.angle,
axis=self.axis,
about_point=self.about_point,
about_edge=self.about_edge,
)
[docs]
class Rotate(Transform):
"""Animation that rotates a Mobject.
Parameters
----------
mobject
The mobject to be rotated.
angle
The rotation angle.
axis
The rotation axis as a numpy vector.
about_point
The rotation center.
about_edge
If ``about_point`` is ``None``, this argument specifies
the direction of the bounding box point to be taken as
the rotation center.
Examples
--------
.. manim:: UsingRotate
class UsingRotate(Scene):
def construct(self):
self.play(
Rotate(
Square(side_length=0.5).shift(UP * 2),
angle=2*PI,
about_point=ORIGIN,
rate_func=linear,
),
Rotate(Square(side_length=0.5), angle=2*PI, rate_func=linear),
)
See also
--------
:class:`~.Rotating`, :meth:`~.Mobject.rotate`
"""
def __init__(
self,
mobject: Mobject,
angle: float = PI,
axis: Vector3DLike = OUT,
about_point: Point3DLike | None = None,
about_edge: Vector3DLike | None = None,
**kwargs: Any,
) -> None:
if "path_arc" not in kwargs:
kwargs["path_arc"] = angle
if "path_arc_axis" not in kwargs:
kwargs["path_arc_axis"] = axis
self.angle = angle
self.axis = axis
self.about_edge = about_edge
self.about_point = about_point
if self.about_point is None:
self.about_point = mobject.get_center()
super().__init__(mobject, path_arc_centers=self.about_point, **kwargs)
def create_target(self) -> Mobject | OpenGLMobject:
target = self.mobject.copy()
target.rotate(
self.angle,
axis=self.axis,
about_point=self.about_point,
about_edge=self.about_edge,
)
return target