def show_ghost_movement(self, vector):
"""
This method plays an animation that partially shows the entire plane moving
in the direction of a particular vector. This is useful when you wish to
convey the idea of mentally moving the entire plane in a direction, without
actually moving the plane.
Parameters
----------
vector (Union[Arrow, list, tuple, np.ndarray])
The vector which indicates the direction of movement.
"""
if isinstance(vector, Arrow):
vector = vector.get_end() - vector.get_start()
elif len(vector) == 2:
vector = np.append(np.array(vector), 0.0)
x_max = int(FRAME_X_RADIUS + abs(vector[0]))
y_max = int(FRAME_Y_RADIUS + abs(vector[1]))
dots = VMobject(*[
Dot(x * RIGHT + y * UP) for x in range(-x_max, x_max)
for y in range(-y_max, y_max)
])
dots.set_fill(BLACK, opacity=0)
dots_halfway = dots.copy().shift(vector / 2).set_fill(WHITE, 1)
dots_end = dots.copy().shift(vector)
self.play(Transform(dots, dots_halfway, rate_func=rush_into))
self.play(Transform(dots, dots_end, rate_func=rush_from))
self.remove(dots)
def show_ghost_movement(self, vector):
if isinstance(vector, Arrow):
vector = vector.get_end() - vector.get_start()
elif len(vector) == 2:
vector = np.append(np.array(vector), 0.0)
x_max = int(FRAME_X_RADIUS + abs(vector[0]))
y_max = int(FRAME_Y_RADIUS + abs(vector[1]))
dots = VMobject(*[
Dot(x * RIGHT + y * UP) for x in range(-x_max, x_max)
for y in range(-y_max, y_max)
])
dots.set_fill(BLACK, opacity=0)
dots_halfway = dots.copy().shift(vector / 2).set_fill(WHITE, 1)
dots_end = dots.copy().shift(vector)
self.play(Transform(dots, dots_halfway, rate_func=rush_into))
self.play(Transform(dots, dots_end, rate_func=rush_from))
self.remove(dots)
def __init__(self, vmobject: VMobject, **kwargs):
super().__init__(**kwargs)
self.vmobject: VMobject = vmobject
self.boundary_copies: list[VMobject] = [
vmobject.copy().set_style(stroke_width=0, fill_opacity=0)
for x in range(2)
]
self.add(*self.boundary_copies)
self.total_time: float = 0
self.add_updater(lambda m, dt: self.update_boundary_copies(dt))
def __init__(self, vmobject: VMobject, stroke_width: float = 2, **kwargs):
digest_config(self, kwargs)
outline = vmobject.copy()
outline.set_fill(opacity=0)
outline.set_stroke(width=stroke_width, opacity=1)
rate_func = kwargs.get("rate_func", smooth)
super().__init__(
FadeIn(vmobject,
rate_func=squish_rate_func(rate_func, self.fade_lag, 1)),
VShowPassingFlash(outline, time_width=1), **kwargs)
def show_ghost_movement(self, vector):
if isinstance(vector, Arrow):
vector = vector.get_end() - vector.get_start()
elif len(vector) == 2:
vector = np.append(np.array(vector), 0.0)
x_max = int(FRAME_X_RADIUS + abs(vector[0]))
y_max = int(FRAME_Y_RADIUS + abs(vector[1]))
dots = VMobject(*[
Dot(x * RIGHT + y * UP)
for x in range(-x_max, x_max)
for y in range(-y_max, y_max)
])
dots.set_fill(BLACK, opacity=0)
dots_halfway = dots.copy().shift(vector / 2).set_fill(WHITE, 1)
dots_end = dots.copy().shift(vector)
self.play(Transform(
dots, dots_halfway, rate_func=rush_into
))
self.play(Transform(
dots, dots_end, rate_func=rush_from
))
self.remove(dots)
def __init__(self, vmobject: VMobject, **kwargs):
digest_config(self, kwargs)
max_stroke_width = vmobject.get_stroke_width()
max_time_width = kwargs.pop("time_width", self.time_width)
AnimationGroup.__init__(self, *[
VShowPassingFlash(
vmobject.copy().set_stroke(width=stroke_width),
time_width=time_width,
**kwargs
)
for stroke_width, time_width in zip(
np.linspace(0, max_stroke_width, self.n_segments),
np.linspace(max_time_width, 0, self.n_segments)
)
])
def get_piece_movement(self, pieces):
start = VMobject(*pieces)
target = VMobject(*[mob.target for mob in pieces])
if self.leave_ghost_vectors:
self.add(start.copy().fade(0.7))
return Transform(start, target, lag_ratio=0)
def get_piece_movement(self, pieces):
start = VMobject(*pieces)
target = VMobject(*[mob.target for mob in pieces])
if self.leave_ghost_vectors:
self.add(start.copy().fade(0.7))
return Transform(start, target, submobject_mode="all_at_once")