2021_01_01_new_year_post_parametric_firework.py

class NewYearPost(MovingCameraScene):
    def construct(self):
        self.camera_frame.move_to(3 * UP)
        text = MathTex(
            r" s(t) &=\left( \begin{array}{c} "
            r"x(t)"
            r"\\ y(t)"
            r"\end{array} \right)"
            r"\\ &=\left( \begin{array}{c} "
            r"v_0 t \cos(\theta)"
            r"\\ v_0 t \sin(\theta) - \frac{1}{2}gt^2"
            r"\end{array} \right)"
        )

        text.to_corner(DL).shift(3 * UP)

        def func(t):
            v0 = 10
            theta = 0.85 * PI / 2
            g = 9.81
            return np.array(
                (v0 * t * np.cos(theta), v0 * t * np.sin(theta) - 0.5 * g * t ** 2, 0)
            )

        rocket = ParametricFunction(func, t_max=1, fill_opacity=0).set_color(WHITE)
        dot = Dot().set_color(WHITE)
        dot2 = Dot().set_color(WHITE).move_to(rocket.get_end())
        self.add(dot)
        self.play(Write(rocket), rate_func=linear)
        self.add(dot2)
        all_sparcs = VGroup()
        for theta in np.random.uniform(0, TAU, 90):

            def func2(t):
                v0 = 10
                g = 9.81
                return np.array(
                    (
                        v0 * t * np.cos(theta) + dot2.get_x(),
                        v0 * t * np.sin(theta) - 0.5 * g * t ** 2 + dot2.get_y(),
                        0,
                    )
                )

            sparcle = ParametricFunction(
                func2, t_min=0.04, t_max=0.3, fill_opacity=0
            ).set_color(ORANGE)
            all_sparcs.add((sparcle))
        self.play(
            *[Write(x) for x in all_sparcs.submobjects], run_time=0.8, rate_func=linear
        )
        dots = [
            Dot(point=[x, y, 0])
            for x, y in zip(np.random.uniform(-4, 4, 10), np.random.uniform(0, 6, 10))
        ]
        self.play(*[Flash(dot) for dot in dots], lag_ratio=0.2)
        dots = [
            Dot(point=[x, y, 0])
            for x, y in zip(np.random.uniform(-4, 4, 10), np.random.uniform(0, 6, 10))
        ]
        self.play(FadeIn(text), *[Flash(dot) for dot in dots], lag_ratio=0.2)
        dots = [
            Dot(point=[x, y, 0])
            for x, y in zip(np.random.uniform(-4, 4, 30), np.random.uniform(0, 6, 30))
        ]
        self.play(*[Flash(dot) for dot in dots], lag_ratio=0.2)

        banner = ManimBanner(dark_theme=True).scale(0.3).to_corner(DR)
        self.play(FadeIn(banner.shift(3 * UP)))
        self.play(banner.expand())
        self.play(FadeOut(banner))