Files
manim/old_projects/hilbert/fractal_porn.py
2018-09-19 08:53:28 +05:30

339 lines
9.2 KiB
Python

from big_ol_pile_of_manim_imports import *
from old_projects.hilbert.curves import *
class Intro(TransformOverIncreasingOrders):
@staticmethod
def args_to_string(*args):
return ""
@staticmethod
def string_to_args(string):
raise Exception("string_to_args Not Implemented!")
def construct(self):
words1 = TextMobject(
"If you watched my video about Hilbert's space-filling curve\\dots"
)
words2 = TextMobject(
"\\dots you might be curious to see what a few other space-filling curves look like."
)
words2.scale(0.8)
for words in words1, words2:
words.to_edge(UP, buff = 0.2)
self.setup(HilbertCurve)
self.play(ShimmerIn(words1))
for x in range(4):
self.increase_order()
self.remove(words1)
self.increase_order(
ShimmerIn(words2)
)
for x in range(4):
self.increase_order()
class BringInPeano(Intro):
def construct(self):
words1 = TextMobject("""
For each one, see if you can figure out what
the pattern of construction is.
""")
words2 = TextMobject("""
This one is the Peano curve.
""")
words3 = TextMobject("""
It is the original space-filling curve.
""")
self.setup(PeanoCurve)
self.play(ShimmerIn(words1))
self.wait(5)
self.remove(words1)
self.add(words2.to_edge(UP))
for x in range(3):
self.increase_order()
self.remove(words2)
self.increase_order(ShimmerIn(words3.to_edge(UP)))
for x in range(2):
self.increase_order()
class FillOtherShapes(Intro):
def construct(self):
words1 = TextMobject("""
But of course, there's no reason we should limit
ourselves to filling in squares.
""")
words2 = TextMobject("""
Here's a simple triangle-filling curve I defined
in a style reflective of a Hilbert curve.
""")
words1.to_edge(UP)
words2.scale(0.8).to_edge(UP, buff = 0.2)
self.setup(TriangleFillingCurve)
self.play(ShimmerIn(words1))
for x in range(3):
self.increase_order()
self.remove(words1)
self.add(words2)
for x in range(5):
self.increase_order()
class SmallerFlowSnake(FlowSnake):
CONFIG = {
"radius" : 4
}
class MostDelightfulName(Intro):
def construct(self):
words1 = TextMobject("""
This one has the most delightful name,
thanks to mathematician/programmer Bill Gosper:
""")
words2 = TextMobject("``Flow Snake''")
words3 = TextMobject("""
What makes this one particularly interesting
is that the boundary itself is a fractal.
""")
for words in words1, words2, words3:
words.to_edge(UP)
self.setup(SmallerFlowSnake)
self.play(ShimmerIn(words1))
for x in range(3):
self.increase_order()
self.remove(words1)
self.add(words2)
for x in range(3):
self.increase_order()
self.remove(words2)
self.play(ShimmerIn(words3))
class SurpriseFractal(Intro):
def construct(self):
words = TextMobject("""
It might come as a surprise how some well-known
fractals can be described with curves.
""")
words.to_edge(UP)
self.setup(Sierpinski)
self.add(TextMobject("Speaking of other fractals\\dots"))
self.wait(3)
self.clear()
self.play(ShimmerIn(words))
for x in range(9):
self.increase_order()
class IntroduceKoch(Intro):
def construct(self):
words = list(map(TextMobject, [
"This is another famous fractal.",
"The ``Koch Snowflake''",
"Let's finish things off by seeing how to turn \
this into a space-filling curve"
]))
for text in words:
text.to_edge(UP)
self.setup(KochCurve)
self.add(words[0])
for x in range(3):
self.increase_order()
self.remove(words[0])
self.add(words[1])
for x in range(4):
self.increase_order()
self.remove(words[1])
self.add(words[2])
self.wait(6)
class StraightKoch(KochCurve):
CONFIG = {
"axiom" : "A"
}
class SharperKoch(StraightKoch):
CONFIG = {
"angle" : 0.9*np.pi/2,
}
class DullerKoch(StraightKoch):
CONFIG = {
"angle" : np.pi/6,
}
class SpaceFillingKoch(StraightKoch):
CONFIG = {
"angle" : np.pi/2,
}
class FromKochToSpaceFilling(Scene):
def construct(self):
self.max_order = 7
self.revisit_koch()
self.show_angles()
self.show_change_side_by_side()
def revisit_koch(self):
words = list(map(TextMobject, [
"First, look at how one section of this curve is made.",
"This pattern of four lines is the ``seed''",
"With each iteration, every straight line is \
replaced with an appropriately small copy of the seed",
]))
for text in words:
text.to_edge(UP)
self.add(words[0])
curve = StraightKoch(order = self.max_order)
self.play(Transform(
curve,
StraightKoch(order = 1),
run_time = 5
))
self.remove(words[0])
self.add(words[1])
self.wait(4)
self.remove(words[1])
self.add(words[2])
self.wait(3)
for order in range(2, self.max_order):
self.play(Transform(
curve,
StraightKoch(order = order)
))
if order == 2:
self.wait(2)
elif order == 3:
self.wait()
self.clear()
def show_angles(self):
words = TextMobject("""
Let's see what happens as we change
the angle in this seed
""")
words.to_edge(UP)
koch, sharper_koch, duller_koch = curves = [
CurveClass(order = 1)
for CurveClass in (StraightKoch, SharperKoch, DullerKoch)
]
arcs = [
Arc(
2*(np.pi/2 - curve.angle),
radius = r,
start_angle = np.pi+curve.angle
).shift(curve.points[curve.get_num_points()/2])
for curve, r in zip(curves, [0.6, 0.7, 0.4])
]
theta = TexMobject("\\theta")
theta.shift(arcs[0].get_center()+2.5*DOWN)
arrow = Arrow(theta, arcs[0])
self.add(words, koch)
self.play(ShowCreation(arcs[0]))
self.play(
ShowCreation(arrow),
ShimmerIn(theta)
)
self.wait(2)
self.remove(theta, arrow)
self.play(
Transform(koch, duller_koch),
Transform(arcs[0], arcs[2]),
)
self.play(
Transform(koch, sharper_koch),
Transform(arcs[0], arcs[1]),
)
self.clear()
def show_change_side_by_side(self):
seed = TextMobject("Seed")
seed.shift(3*LEFT+2*DOWN)
fractal = TextMobject("Fractal")
fractal.shift(3*RIGHT+2*DOWN)
words = list(map(TextMobject, [
"A sharper angle results in a richer curve",
"A more obtuse angle gives a sparser curve",
"And as the angle approaches 0\\dots",
"We have a new space-filling curve."
]))
for text in words:
text.to_edge(UP)
sharper, duller, space_filling = [
CurveClass(order = 1).shift(3*LEFT)
for CurveClass in (SharperKoch, DullerKoch, SpaceFillingKoch)
]
shaper_f, duller_f, space_filling_f = [
CurveClass(order = self.max_order).shift(3*RIGHT)
for CurveClass in (SharperKoch, DullerKoch, SpaceFillingKoch)
]
self.add(words[0])
left_curve = SharperKoch(order = 1)
right_curve = SharperKoch(order = 1)
self.play(
Transform(left_curve, sharper),
ApplyMethod(right_curve.shift, 3*RIGHT),
)
self.play(
Transform(
right_curve,
SharperKoch(order = 2).shift(3*RIGHT)
),
ShimmerIn(seed),
ShimmerIn(fractal)
)
for order in range(3, self.max_order):
self.play(Transform(
right_curve,
SharperKoch(order = order).shift(3*RIGHT)
))
self.remove(words[0])
self.add(words[1])
kwargs = {
"run_time" : 4,
}
self.play(
Transform(left_curve, duller, **kwargs),
Transform(right_curve, duller_f, **kwargs)
)
self.wait()
kwargs["run_time"] = 7
kwargs["rate_func"] = None
self.remove(words[1])
self.add(words[2])
self.play(
Transform(left_curve, space_filling, **kwargs),
Transform(right_curve, space_filling_f, **kwargs)
)
self.remove(words[2])
self.add(words[3])
self.wait()