rate_functions¶
选择速率函数，即动画的速度曲线。 请查看标准列表https://easings.net/。这里是非标准速率函数的图片
示例：RateFuncExample ¶
from manim import *
class RateFuncExample(Scene):
def construct(self):
x = VGroup()
for k, v in rate_functions.__dict__.items():
if "function" in str(v):
if (
not k.startswith("__")
and not k.startswith("sqrt")
and not k.startswith("bezier")
):
try:
rate_func = v
plot = (
ParametricFunction(
lambda x: [x, rate_func(x), 0],
t_range=[0, 1, .01],
use_smoothing=False,
color=YELLOW,
)
.stretch_to_fit_width(1.5)
.stretch_to_fit_height(1)
)
plot_bg = SurroundingRectangle(plot).set_color(WHITE)
plot_title = (
Text(rate_func.__name__, weight=BOLD)
.scale(0.5)
.next_to(plot_bg, UP, buff=0.1)
)
x.add(VGroup(plot_bg, plot, plot_title))
except: # because functions `not_quite_there`, `function squish_rate_func` are not working.
pass
x.arrange_in_grid(cols=8)
x.height = config.frame_height
x.width = config.frame_width
x.move_to(ORIGIN).scale(0.95)
self.add(x)
class RateFuncExample(Scene):
def construct(self):
x = VGroup()
for k, v in rate_functions.__dict__.items():
if "function" in str(v):
if (
not k.startswith("__")
and not k.startswith("sqrt")
and not k.startswith("bezier")
):
try:
rate_func = v
plot = (
ParametricFunction(
lambda x: [x, rate_func(x), 0],
t_range=[0, 1, .01],
use_smoothing=False,
color=YELLOW,
)
.stretch_to_fit_width(1.5)
.stretch_to_fit_height(1)
)
plot_bg = SurroundingRectangle(plot).set_color(WHITE)
plot_title = (
Text(rate_func.__name__, weight=BOLD)
.scale(0.5)
.next_to(plot_bg, UP, buff=0.1)
)
x.add(VGroup(plot_bg, plot, plot_title))
except: # because functions `not_quite_there`, `function squish_rate_func` are not working.
pass
x.arrange_in_grid(cols=8)
x.height = config.frame_height
x.width = config.frame_width
x.move_to(ORIGIN).scale(0.95)
self.add(x)
主要有三种标准缓动函数：
缓入 - 动画有一个平滑的开始。
缓出 - 动画有一个平滑的结束。
缓入缓出 - 动画有一个平滑的开始和平滑的结束。
注意
标准函数不会被导出，因此要使用它们，你需要这样做： rate_func=rate_functions.ease_in_sine 另一方面，非标准函数更常用，它们被导出并可以直接使用。
示例：RateFunctions1示例 ¶
from manim import *
class RateFunctions1Example(Scene):
def construct(self):
line1 = Line(3*LEFT, 3*RIGHT).shift(UP).set_color(RED)
line2 = Line(3*LEFT, 3*RIGHT).set_color(GREEN)
line3 = Line(3*LEFT, 3*RIGHT).shift(DOWN).set_color(BLUE)
dot1 = Dot().move_to(line1.get_left())
dot2 = Dot().move_to(line2.get_left())
dot3 = Dot().move_to(line3.get_left())
label1 = Tex("Ease In").next_to(line1, RIGHT)
label2 = Tex("Ease out").next_to(line2, RIGHT)
label3 = Tex("Ease In Out").next_to(line3, RIGHT)
self.play(
FadeIn(VGroup(line1, line2, line3)),
FadeIn(VGroup(dot1, dot2, dot3)),
Write(VGroup(label1, label2, label3)),
)
self.play(
MoveAlongPath(dot1, line1, rate_func=rate_functions.ease_in_sine),
MoveAlongPath(dot2, line2, rate_func=rate_functions.ease_out_sine),
MoveAlongPath(dot3, line3, rate_func=rate_functions.ease_in_out_sine),
run_time=7
)
self.wait()
class RateFunctions1Example(Scene):
def construct(self):
line1 = Line(3*LEFT, 3*RIGHT).shift(UP).set_color(RED)
line2 = Line(3*LEFT, 3*RIGHT).set_color(GREEN)
line3 = Line(3*LEFT, 3*RIGHT).shift(DOWN).set_color(BLUE)
dot1 = Dot().move_to(line1.get_left())
dot2 = Dot().move_to(line2.get_left())
dot3 = Dot().move_to(line3.get_left())
label1 = Tex("Ease In").next_to(line1, RIGHT)
label2 = Tex("Ease out").next_to(line2, RIGHT)
label3 = Tex("Ease In Out").next_to(line3, RIGHT)
self.play(
FadeIn(VGroup(line1, line2, line3)),
FadeIn(VGroup(dot1, dot2, dot3)),
Write(VGroup(label1, label2, label3)),
)
self.play(
MoveAlongPath(dot1, line1, rate_func=rate_functions.ease_in_sine),
MoveAlongPath(dot2, line2, rate_func=rate_functions.ease_out_sine),
MoveAlongPath(dot3, line3, rate_func=rate_functions.ease_in_out_sine),
run_time=7
)
self.wait()
函数
- not_quite_there(func=<function smooth>, proportion=0.7)[source]¶
- Parameters:
func (Callable[[float], float])
比例 (浮点数)
- Return type:
可调用[[float], float]
- running_start(t, pull_factor=-0.5)[source]¶
- Parameters:
t (浮点数)
pull_factor (float)
- Return type:
可迭代
- smoothererstep(t)[source]¶
实现三阶SmoothStep sigmoid函数。 在端点处，一阶、二阶和三阶导数（速度、加速度和加加速度）为零。 https://en.wikipedia.org/wiki/Smoothstep
- Parameters:
t (浮点数)
- Return type:
浮点数
- smootherstep(t)[来源]¶
实现二阶SmoothStep sigmoid函数。 一阶和二阶导数（速度和加速度）在端点处为零。 https://en.wikipedia.org/wiki/Smoothstep
- Parameters:
t (浮点数)
- Return type:
浮点数
- smoothstep(t)[来源]¶
实现一阶SmoothStep sigmoid函数。 一阶导数（速度）在端点处为零。 https://en.wikipedia.org/wiki/Smoothstep
- Parameters:
t (浮点数)
- Return type:
浮点数
- squish_rate_func(func, a=0.4, b=0.6)[source]¶
- Parameters:
func (Callable[[float], float])
a (浮点数)
b (浮点数)
- Return type:
可调用[[float], float]