五芒星

预览

代码

from manim import *

class Studying(Scene):
    def construct(self):
        circle = Circle(radius=0.81,color=BLUE_B)
        self.play(Create(circle))
        # 点的透明度为0，即看不到点
        dot = Dot(point=[0.8,0,0],color=BLUE_B,fill_opacity=0)
        self.play(FadeIn(dot))

        # 五角星的五个点
        points = VGroup()
        R = 0.8
        for k in range(5):
            angle = k * (2 * PI * 2 / 5)  # 每个点间隔 144°（=2/5圈）
            x = R * np.cos(angle)
            y = R * np.sin(angle)
            dot_k = dot.copy().move_to([x, y, 0])
            points.add(dot_k)

        # 第一个创建的点渐隐
        self.play(FadeOut(dot))

        # 五个点渐现
        for point in points:
            self.play(FadeIn(point),run_time=0.1)
            self.wait(0.5)
        # 五个点连成五角星  
        hexagon = always_redraw(lambda:
            Polygon(
                *[point.get_center() for point in points],
                stroke_width=2,
                color=BLUE_B)
                )
        self.play(Create(hexagon),run_time=2)
        self.wait(1)

        # 旋转五芒星
        self.play(
            Rotating(VGroup(points,hexagon),
            about_point=ORIGIN,
            angle=4*TAU,
            run_time=4,
            rate_func=linear)
        )