可视化库之三 3brown1blue 秘密利器 manim
2022-03-23 本文已影响0人
Python_Camp
这个图库包含了一系列的最佳实践代码片段，以及相应的视频/图片输出，说明了整个库的不同功能。这些都是在MIT许可下的，所以可以随意复制和粘贴到你的项目中。请享受这个Manim的味道!
提示
在我们的文档中，这个画廊并不是唯一可以看到明确的代码和视频例子的地方：在我们的参考手册中还有很多--例如，参见我们关于tex_mobject, geometry, moving_camera_scene等模块的文档。
看看我们的交互式Jupyter环境，它允许在线运行这些例子，而不需要本地安装。
另外，请访问我们的推，以获得更多的演示文稿。
image.png
from manim import *
class ExampleRotation(Scene):
def construct(self):
self.camera.background_color = WHITE
m1a = Square().set_color(RED).shift(LEFT)
m1b = Circle().set_color(RED).shift(LEFT)
m2a= Square().set_color(BLUE).shift(RIGHT)
m2b= Circle().set_color(BLUE).shift(RIGHT)
points = m2a.points
points = np.roll(points, int(len(points)/4), axis=0)
m2a.points = points
self.play(Transform(m1a,m1b),Transform(m2a,m2b), run_time=1)
image.png
from manim import *
class PointMovingOnShapes(Scene):
def construct(self):
circle = Circle(radius=1, color=BLUE)
dot = Dot()
dot2 = dot.copy().shift(RIGHT)
self.add(dot)
line = Line([3, 0, 0], [5, 0, 0])
self.add(line)
self.play(GrowFromCenter(circle))
self.play(Transform(dot, dot2))
self.play(MoveAlongPath(dot, circle), run_time=2, rate_func=linear)
self.play(Rotating(dot, about_point=[2, 0, 0]), run_time=1.5)
self.wait()
image.png
from manim import *
class MovingGroupToDestination(Scene):
def construct(self):
group = VGroup(Dot(LEFT), Dot(ORIGIN), Dot(RIGHT, color=RED), Dot(2 * RIGHT)).scale(1.4)
dest = Dot([4, 3, 0], color=YELLOW)
self.add(group, dest)
self.play(group.animate.shift(dest.get_center() - group[2].get_center()))
self.wait(0.5)
image.png
from manim import *
class MovingFrameBox(Scene):
def construct(self):
text=MathTex(
"\\frac{d}{dx}f(x)g(x)=","f(x)\\frac{d}{dx}g(x)","+",
"g(x)\\frac{d}{dx}f(x)"
)
self.play(Write(text))
framebox1 = SurroundingRectangle(text[1], buff = .1)
framebox2 = SurroundingRectangle(text[3], buff = .1)
self.play(
Create(framebox1),
)
self.wait()
self.play(
ReplacementTransform(framebox1,framebox2),
)
self.wait()
image.png
from manim import *
class SinAndCosFunctionPlot(Scene):
def construct(self):
axes = Axes(
x_range=[-10, 10.3, 1],
y_range=[-1.5, 1.5, 1],
x_length=10,
axis_config={"color": GREEN},
x_axis_config={
"numbers_to_include": np.arange(-10, 10.01, 2),
"numbers_with_elongated_ticks": np.arange(-10, 10.01, 2),
},
tips=False,
)
axes_labels = axes.get_axis_labels()
sin_graph = axes.plot(lambda x: np.sin(x), color=BLUE)
cos_graph = axes.plot(lambda x: np.cos(x), color=RED)
sin_label = axes.get_graph_label(
sin_graph, "\\sin(x)", x_val=-10, direction=UP / 2
)
cos_label = axes.get_graph_label(cos_graph, label="\\cos(x)")
vert_line = axes.get_vertical_line(
axes.i2gp(TAU, cos_graph), color=YELLOW, line_func=Line
)
line_label = axes.get_graph_label(
cos_graph, "x=2\pi", x_val=TAU, direction=UR, color=WHITE
)
plot = VGroup(axes, sin_graph, cos_graph, vert_line)
labels = VGroup(axes_labels, sin_label, cos_label, line_label)
self.add(plot, labels)
image.png
from manim import *
class GraphAreaPlot(Scene):
def construct(self):
ax = Axes(
x_range=[0, 5],
y_range=[0, 6],
x_axis_config={"numbers_to_include": [2, 3]},
tips=False,
)
labels = ax.get_axis_labels()
curve_1 = ax.plot(lambda x: 4 * x - x ** 2, x_range=[0, 4], color=BLUE_C)
curve_2 = ax.plot(
lambda x: 0.8 * x ** 2 - 3 * x + 4,
x_range=[0, 4],
color=GREEN_B,
)
line_1 = ax.get_vertical_line(ax.input_to_graph_point(2, curve_1), color=YELLOW)
line_2 = ax.get_vertical_line(ax.i2gp(3, curve_1), color=YELLOW)
riemann_area = ax.get_riemann_rectangles(curve_1, x_range=[0.3, 0.6], dx=0.03, color=BLUE, fill_opacity=0.5)
area = ax.get_area(curve_2, [2, 3], bounded_graph=curve_1, color=GREY, opacity=0.5)
self.add(ax, labels, curve_1, curve_2, line_1, line_2, riemann_area, area)
image.png
from manim import *
class ThreeDSurfacePlot(ThreeDScene):
def construct(self):
resolution_fa = 42
self.set_camera_orientation(phi=75 * DEGREES, theta=-30 * DEGREES)
def param_gauss(u, v):
x = u
y = v
sigma, mu = 0.4, [0.0, 0.0]
d = np.linalg.norm(np.array([x - mu[0], y - mu[1]]))
z = np.exp(-(d ** 2 / (2.0 * sigma ** 2)))
return np.array([x, y, z])
gauss_plane = Surface(
param_gauss,
resolution=(resolution_fa, resolution_fa),
v_range=[-2, +2],
u_range=[-2, +2]
)
gauss_plane.scale(2, about_point=ORIGIN)
gauss_plane.set_style(fill_opacity=1,stroke_color=GREEN)
gauss_plane.set_fill_by_checkerboard(ORANGE, BLUE, opacity=0.5)
axes = ThreeDAxes()
self.add(axes,gauss_plane)
image.png
from manim import *
class OpeningManim(Scene):
def construct(self):
title = Tex(r"This is some \LaTeX")
basel = MathTex(r"\sum_{n=1}^\infty \frac{1}{n^2} = \frac{\pi^2}{6}")
VGroup(title, basel).arrange(DOWN)
self.play(
Write(title),
FadeIn(basel, shift=DOWN),
)
self.wait()
transform_title = Tex("That was a transform")
transform_title.to_corner(UP + LEFT)
self.play(
Transform(title, transform_title),
LaggedStart(*[FadeOut(obj, shift=DOWN) for obj in basel]),
)
self.wait()
grid = NumberPlane()
grid_title = Tex("This is a grid", font_size=72)
grid_title.move_to(transform_title)
self.add(grid, grid_title) # Make sure title is on top of grid
self.play(
FadeOut(title),
FadeIn(grid_title, shift=UP),
Create(grid, run_time=3, lag_ratio=0.1),
)
self.wait()
grid_transform_title = Tex(
r"That was a non-linear function \\ applied to the grid"
)
grid_transform_title.move_to(grid_title, UL)
grid.prepare_for_nonlinear_transform()
self.play(
grid.animate.apply_function(
lambda p: p
+ np.array(
[
np.sin(p[1]),
np.sin(p[0]),
0,
]
)
),
run_time=3,
)
self.wait()
self.play(Transform(grid_title, grid_transform_title))
self.wait()
image.png
from manim import *
class SineCurveUnitCircle(Scene):
# contributed by heejin_park, https://infograph.tistory.com/230
def construct(self):
self.show_axis()
self.show_circle()
self.move_dot_and_draw_curve()
self.wait()
def show_axis(self):
x_start = np.array([-6,0,0])
x_end = np.array([6,0,0])
y_start = np.array([-4,-2,0])
y_end = np.array([-4,2,0])
x_axis = Line(x_start, x_end)
y_axis = Line(y_start, y_end)
self.add(x_axis, y_axis)
self.add_x_labels()
self.origin_point = np.array([-4,0,0])
self.curve_start = np.array([-3,0,0])
def add_x_labels(self):
x_labels = [
MathTex("\pi"), MathTex("2 \pi"),
MathTex("3 \pi"), MathTex("4 \pi"),
]
for i in range(len(x_labels)):
x_labels[i].next_to(np.array([-1 + 2*i, 0, 0]), DOWN)
self.add(x_labels[i])
def show_circle(self):
circle = Circle(radius=1)
circle.move_to(self.origin_point)
self.add(circle)
self.circle = circle
def move_dot_and_draw_curve(self):
orbit = self.circle
origin_point = self.origin_point
dot = Dot(radius=0.08, color=YELLOW)
dot.move_to(orbit.point_from_proportion(0))
self.t_offset = 0
rate = 0.25
def go_around_circle(mob, dt):
self.t_offset += (dt * rate)
# print(self.t_offset)
mob.move_to(orbit.point_from_proportion(self.t_offset % 1))
def get_line_to_circle():
return Line(origin_point, dot.get_center(), color=BLUE)
def get_line_to_curve():
x = self.curve_start[0] + self.t_offset * 4
y = dot.get_center()[1]
return Line(dot.get_center(), np.array([x,y,0]), color=YELLOW_A, stroke_width=2 )
self.curve = VGroup()
self.curve.add(Line(self.curve_start,self.curve_start))
def get_curve():
last_line = self.curve[-1]
x = self.curve_start[0] + self.t_offset * 4
y = dot.get_center()[1]
new_line = Line(last_line.get_end(),np.array([x,y,0]), color=YELLOW_D)
self.curve.add(new_line)
return self.curve
dot.add_updater(go_around_circle)
origin_to_circle_line = always_redraw(get_line_to_circle)
dot_to_curve_line = always_redraw(get_line_to_curve)
sine_curve_line = always_redraw(get_curve)
self.add(dot)
self.add(orbit, origin_to_circle_line, dot_to_curve_line, sine_curve_line)
self.wait(8.5)
dot.remove_updater(go_around_circle)
场景
场景类是manim的连接组织。每个mobject都必须被添加到一个场景中才能被显示，或者从场景中移除才能停止显示。每个动画都必须由一个场景来播放，每个没有动画发生的时间间隔都由调用wait()来决定。你的视频的所有代码都必须包含在一个派生自Scene的类的construct()方法中。最后，如果要同时渲染多个场景，一个文件可以包含多个Scene子类。
