Merge pull request #752 from 3b1b/hyperdarts

Hyperdarts

active_projects/hyperdarts.py

@@ -0,0 +1,920 @@
+from manimlib.imports import *
+
+
+OUTPUT_DIRECTORY = "hyperdarts"
+
+
+class HyperdartScene(Scene):
+    CONFIG = {
+        "square_width": 6,
+        "square_style": {
+            "stroke_width": 2,
+            "fill_color": BLUE,
+            "fill_opacity": 0.5,
+        },
+        "circle_style": {
+            "fill_color": RED_E,
+            "fill_opacity": 1,
+            "stroke_width": 0,
+        },
+        "circle_center_dot_radius": 0.025,
+        "default_line_style": {
+            "stroke_width": 2,
+            "stroke_color": WHITE,
+        },
+        "default_dot_config": {
+            "fill_color": WHITE,
+            "background_stroke_width": 1,
+            "background_stroke_color": BLACK,
+            "radius": 0.5 * DEFAULT_DOT_RADIUS,
+        },
+        "dart_sound": "dart_low",
+        "default_bullseye_shadow_opacity": 0.35,
+    }
+
+    def setup(self):
+        self.square = self.get_square()
+        self.circle = self.get_circle()
+        self.circle_center_dot = self.get_circle_center_dot()
+
+        self.add(self.square)
+        self.add(self.circle)
+        self.add(self.circle_center_dot)
+
+    def get_square(self):
+        return Square(
+            side_length=self.square_width,
+            **self.square_style
+        )
+
+    def get_circle(self, square=None):
+        square = square or self.square
+        circle = Circle(**self.circle_style)
+        circle.replace(square)
+        return circle
+
+    def get_circle_center_dot(self, circle=None):
+        circle = circle or self.circle
+        return Dot(
+            circle.get_center(),
+            radius=self.circle_center_dot_radius,
+            fill_color=BLACK,
+        )
+
+    def get_number_plane(self):
+        square = self.square
+        unit_size = square.get_width() / 2
+        plane = NumberPlane(
+            axis_config={
+                "unit_size": unit_size,
+            }
+        )
+        plane.add_coordinates()
+        plane.shift(square.get_center() - plane.c2p(0, 0))
+        return plane
+
+    def get_random_points(self, n):
+        square = self.square
+        points = np.random.uniform(-1, 1, 3 * n).reshape((n, 3))
+
+        points[:, 0] *= square.get_width() / 2
+        points[:, 1] *= square.get_height() / 2
+        points[:, 2] = 0
+        points += square.get_center()
+        return points
+
+    def get_random_point(self):
+        return self.get_random_points(1)[0]
+
+    def get_dot(self, point):
+        return Dot(point, **self.default_dot_config)
+
+    # Hit transform rules
+    def is_inside(self, point, circle=None):
+        circle = circle or self.circle
+        return get_norm(point - circle.get_center()) <= circle.get_width() / 2
+
+    def get_new_radius(self, point, circle=None):
+        circle = circle or self.circle
+        center = circle.get_center()
+        radius = circle.get_width() / 2
+        p_dist = get_norm(point - center)
+        return np.sqrt(radius**2 - p_dist**2)
+
+    def get_hit_distance_line(self, point, circle=None):
+        circle = circle or self.circle
+
+        line = Line(
+            circle.get_center(), point,
+            **self.default_line_style
+        )
+        return line
+
+    def get_chord(self, point, circle=None):
+        circle = circle or self.circle
+
+        center = circle.get_center()
+        p_angle = angle_of_vector(point - center)
+        chord = Line(DOWN, UP)
+        new_radius = self.get_new_radius(point, circle)
+        chord.scale(new_radius)
+        chord.rotate(p_angle)
+        chord.move_to(point)
+        chord.set_style(**self.default_line_style)
+        return chord
+
+    def get_radii_to_chord(self, chord, circle=None):
+        circle = circle or self.circle
+
+        center = circle.get_center()
+        radii = VGroup(*[
+            DashedLine(center, point)
+            for point in chord.get_start_and_end()
+        ])
+        radii.set_style(**self.default_line_style)
+        return radii
+
+    def get_all_hit_lines(self, point, circle=None):
+        h_line = self.get_hit_distance_line(point, circle)
+        chord = self.get_chord(point, circle)
+        radii = self.get_radii_to_chord(chord, circle)
+        return VGroup(h_line, chord, radii)
+
+    def get_dart(self, length=1.5):
+        dart = SVGMobject(file_name="dart")
+        dart.rotate(135 * DEGREES)
+        dart.set_width(length)
+        dart.rotate(45 * DEGREES, UP)
+        dart.rotate(-10 * DEGREES)
+
+        dart.set_fill(GREY)
+        dart.set_sheen(2, UL)
+        dart.set_stroke(BLACK, 0.5, background=True)
+        return dart
+
+    # New circle
+    def get_new_circle_from_point(self, point, circle=None):
+        return self.get_new_circle(
+            self.get_new_radius(point, circle),
+            circle,
+        )
+
+    def get_new_circle_from_chord(self, chord, circle=None):
+        return self.get_new_circle(
+            chord.get_length() / 2,
+            circle,
+        )
+
+    def get_new_circle(self, new_radius, circle=None):
+        circle = circle or self.circle
+        new_circle = self.get_circle()
+        new_circle.set_width(2 * new_radius)
+        new_circle.move_to(circle)
+        return new_circle
+
+    # Sound
+    def add_dart_sound(self, time_offset=0, gain=-20, **kwargs):
+        self.add_sound(
+            self.dart_sound,
+            time_offset=time_offset,
+            gain=-20,
+            **kwargs,
+        )
+
+    # Animations
+    def show_full_hit_process(self, point, pace="slow", with_dart=True):
+        assert(pace in ["slow", "fast"])
+
+        to_fade = VGroup()
+
+        if with_dart:
+            dart, dot = self.show_hit_with_dart(point)
+            to_fade.add(dart, dot)
+        else:
+            dot = self.show_hit(point)
+            to_fade.add(dot)
+
+        if pace == "slow":
+            self.wait(0.5)
+
+        # TODO, automatically act based on hit or miss?
+
+        lines = self.show_geometry(point, pace)
+        chord_and_shadow = self.show_circle_shrink(lines[1], pace=pace)
+
+        to_fade.add_to_back(chord_and_shadow, lines)
+
+        self.play(
+            FadeOut(to_fade),
+            run_time=(1 if pace == "slow" else 0.5)
+        )
+
+    def show_hits_with_darts(self, points, run_time=0.5, added_anims=None):
+        if added_anims is None:
+            added_anims = []
+
+        darts = VGroup(*[
+            self.get_dart().move_to(point, DR)
+            for point in points
+        ])
+        dots = VGroup(*[
+            self.get_dot(point)
+            for point in points
+        ])
+
+        for dart in darts:
+            dart.save_state()
+            dart.set_x(-(FRAME_WIDTH + dart.get_width()) / 2)
+            dart.rotate(20 * DEGREES)
+
+        n_points = len(points)
+        self.play(
+            ShowIncreasingSubsets(
+                dots,
+                rate_func=squish_rate_func(linear, 0.5, 1),
+            ),
+            LaggedStart(*[
+                Restore(
+                    dart,
+                    path_arc=-20 * DEGREES,
+                    rate_func=linear,
+                    run_time=run_time,
+                )
+                for dart in darts
+            ], lag_ratio=(1 / n_points)),
+            *added_anims,
+            run_time=run_time
+        )
+        for n in range(n_points):
+            self.add_dart_sound(
+                time_offset=(-n / (2 * n_points))
+            )
+
+        return darts, dots
+
+    def show_hit_with_dart(self, point, run_time=0.25, **kwargs):
+        darts, dots = self.show_hits_with_darts([point], run_time, **kwargs)
+        return darts[0], dots[0]
+
+    def show_hit(self, point, pace="slow", added_anims=None):
+        assert(pace in ["slow", "fast"])
+        if added_anims is None:
+            added_anims = []
+
+        dot = self.get_dot(point)
+        if pace == "slow":
+            self.play(
+                FadeInFromLarge(dot, rate_func=rush_into),
+                *added_anims,
+                run_time=0.5,
+            )
+        elif pace == "fast":
+            self.add(dot)
+        # self.add_dart_sound()
+        return dot
+
+    def show_geometry(self, point, pace="slow"):
+        assert(pace in ["slow", "fast"])
+
+        lines = self.get_all_hit_lines(point, self.circle)
+        h_line, chord, radii = lines
+
+        if pace == "slow":
+            self.play(
+                ShowCreation(h_line),
+                GrowFromCenter(chord),
+            )
+            self.play(*map(ShowCreation, radii))
+        elif pace == "fast":
+            self.play(
+                ShowCreation(h_line),
+                GrowFromCenter(chord),
+                *map(ShowCreation, radii),
+                run_time=0.5
+            )
+        return lines
+
+    def show_circle_shrink(self, chord, pace="slow", shadow_opacity=None):
+        circle = self.circle
+        chord_copy = chord.copy()
+        new_circle = self.get_new_circle_from_chord(chord)
+        to_fade = VGroup(chord_copy)
+
+        if shadow_opacity is None:
+            shadow_opacity = self.default_bullseye_shadow_opacity
+        if shadow_opacity > 0:
+            shadow = circle.copy()
+            shadow.set_opacity(shadow_opacity)
+            to_fade.add_to_back(shadow)
+            if circle in self.mobjects:
+                index = self.mobjects.index(circle)
+                self.mobjects.insert(index, shadow)
+            else:
+                self.add(shadow, self.circle_center_dot)
+
+        outline = VGroup(*[
+            VMobject().pointwise_become_partial(new_circle, a, b)
+            for (a, b) in [(0, 0.5), (0.5, 1)]
+        ])
+        outline.rotate(chord.get_angle())
+        outline.set_fill(opacity=0)
+        outline.set_stroke(YELLOW, 2)
+
+        assert(pace in ["slow", "fast"])
+
+        if pace == "slow":
+            self.play(
+                chord_copy.move_to, circle.get_center(),
+                circle.set_opacity, 0.5,
+            )
+            self.play(
+                Rotating(
+                    chord_copy,
+                    radians=PI,
+                ),
+                ShowCreation(
+                    outline,
+                    lag_ratio=0
+                ),
+                run_time=1,
+                rate_func=smooth,
+            )
+            self.play(
+                Transform(circle, new_circle),
+                FadeOut(outline),
+            )
+        elif pace == "fast":
+            outline = new_circle.copy()
+            outline.set_fill(opacity=0)
+            outline.set_stroke(YELLOW, 2)
+            outline.move_to(chord)
+            outline.generate_target()
+            outline.target.move_to(circle)
+            self.play(
+                chord_copy.move_to, circle,
+                Transform(circle, new_circle),
+                # MoveToTarget(
+                #     outline,
+                #     remover=True
+                # )
+            )
+            # circle.become(new_circle)
+            # circle.become(new_circle)
+            # self.remove(new_circle)
+        return to_fade
+
+    def show_miss(self, point, with_dart=True):
+        square = self.square
+        miss = TextMobject("Miss!")
+        miss.next_to(point, UP)
+        to_fade = VGroup(miss)
+
+        if with_dart:
+            dart, dot = self.show_hit_with_dart(point)
+            to_fade.add(dart, dot)
+        else:
+            dot = self.show_hit(point)
+            to_fade.add(dot)
+        self.play(
+            ApplyMethod(
+                square.set_color, YELLOW,
+                rate_func=lambda t: (1 - t),
+            ),
+            GrowFromCenter(miss),
+            run_time=0.25
+        )
+        return to_fade
+
+    def show_game_over(self):
+        game_over = TextMobject("GAME OVER")
+        game_over.set_width(FRAME_WIDTH - 1)
+        rect = FullScreenFadeRectangle(opacity=0.25)
+
+        self.play(
+            FadeIn(rect),
+            FadeInFromLarge(game_over),
+        )
+        return VGroup(rect, game_over)
+
+
+class Dartboard(VGroup):
+    CONFIG = {
+        "radius": 3,
+        "n_sectors": 20,
+    }
+
+    def __init__(self, **kwargs):
+        super().__init__(**kwargs)
+        n_sectors = self.n_sectors
+        angle = TAU / n_sectors
+
+        segments = VGroup(*[
+            VGroup(*[
+                AnnularSector(
+                    inner_radius=in_r,
+                    outer_radius=out_r,
+                    start_angle=n * angle,
+                    angle=angle,
+                    color=color,
+                )
+                for n, color in zip(
+                    range(n_sectors),
+                    it.cycle(colors)
+                )
+            ])
+            for colors, in_r, out_r in [
+                ([LIGHT_GREY, DARKER_GREY], 0, 1),
+                ([GREEN_E, RED_E], 0.5, 0.55),
+                ([GREEN_E, RED_E], 0.95, 1),
+            ]
+        ])
+        segments.rotate(-angle / 2)
+        bullseyes = VGroup(*[
+            Circle(radius=r)
+            for r in [0.07, 0.035]
+        ])
+        bullseyes.set_fill(opacity=1)
+        bullseyes.set_stroke(width=0)
+        bullseyes[0].set_color(GREEN_E)
+        bullseyes[1].set_color(RED_E)
+
+        self.add(*segments, *bullseyes)
+        self.scale(self.radius)
+
+
+# Problem statement
+
+class IntroduceGame(HyperdartScene):
+    CONFIG = {
+        "random_seed": 0,
+        "square_width": 5,
+        "num_darts_in_initial_flurry": 5,
+    }
+
+    def construct(self):
+        self.show_flurry_of_points()
+        self.show_board_dimensions()
+        self.introduce_bullseye()
+        self.show_miss_example()
+        self.show_shrink_rule()
+
+    def show_flurry_of_points(self):
+        square = self.square
+        circle = self.circle
+
+        title = TextMobject("Hyperdarts")
+        title.scale(1.5)
+        title.to_edge(UP)
+
+        n = self.num_darts_in_initial_flurry
+        points = np.random.normal(size=n * 3).reshape((n, 3))
+        points[:, 2] = 0
+        points *= 0.75
+
+        board = Dartboard()
+        board.match_width(square)
+        board.move_to(square)
+
+        pre_square = Circle(color=WHITE)
+        pre_square.replace(square)
+
+        self.remove(circle, square)
+        self.add(board)
+
+        darts, dots = self.show_hits_with_darts(
+            points,
+            added_anims=[FadeInFromDown(title)]
+        )
+        self.wait()
+
+        def func(p):
+            theta = angle_of_vector(p) % (TAU / 4)
+            if theta > TAU / 8:
+                theta = TAU / 4 - theta
+            p *= 1 / np.cos(theta)
+            return p
+
+        self.play(
+            *[
+                ApplyPointwiseFunction(func, pieces, run_time=1)
+                for pieces in [*board[:3], *dots]
+            ],
+            *[
+                MaintainPositionRelativeTo(dart, dot)
+                for dart, dot in zip(darts, dots)
+            ]
+        )
+
+        self.flurry_dots = dots
+        self.darts = darts
+        self.title = title
+        self.board = board
+
+    def show_board_dimensions(self):
+        square = self.square
+
+        labels = VGroup(*[
+            TextMobject("2 ft").next_to(
+                square.get_edge_center(vect), vect,
+            )
+            for vect in [DOWN, RIGHT]
+        ])
+        labels.set_color(YELLOW)
+
+        h_line, v_line = lines = VGroup(*[
+            DashedLine(
+                square.get_edge_center(v1),
+                square.get_edge_center(-v1),
+            ).next_to(label, v2)
+            for label, v1, v2 in zip(labels, [LEFT, UP], [UP, LEFT])
+        ])
+        lines.match_color(labels)
+
+        self.play(
+            LaggedStartMap(ShowCreation, lines),
+            LaggedStartMap(FadeInFromDown, labels),
+            lag_ratio=0.5
+        )
+        self.wait()
+
+        self.square_dimensions = VGroup(lines, labels)
+
+    def introduce_bullseye(self):
+        square = self.square
+        circle = self.circle
+        board = self.board
+        circle.save_state()
+        circle.replace(board[-1])
+
+        label = TextMobject("Bullseye")
+        label.scale(1.5)
+        label.next_to(square, LEFT, aligned_edge=UP)
+        label.set_color(RED)
+        arrow = Arrow(
+            label.get_bottom(),
+            circle.get_corner(DR)
+        )
+
+        radius = DashedLine(
+            square.get_center(),
+            square.get_left(),
+            stroke_width=2,
+        )
+        radius_label = TextMobject("1 ft")
+        radius_label.next_to(radius, DOWN, SMALL_BUFF)
+
+        self.add(circle, self.square_dimensions)
+        self.play(
+            FadeInFromLarge(circle),
+            FadeInFromDown(label),
+            ShowCreation(arrow),
+            LaggedStartMap(FadeOut, self.flurry_dots, run_time=1),
+            LaggedStartMap(FadeOut, self.darts, run_time=1),
+        )
+        self.wait()
+        self.add(square, board, arrow, circle)
+        self.play(
+            Restore(circle),
+            ApplyMethod(
+                arrow.scale, 0.4,
+                {"about_point": arrow.get_start()}
+            ),
+        )
+        self.add(radius, self.circle_center_dot)
+        self.play(
+            ShowCreation(radius),
+            FadeInFrom(radius_label, RIGHT),
+            FadeIn(self.circle_center_dot),
+        )
+        self.play(
+            FadeOut(label),
+            Uncreate(arrow),
+            FadeOut(board)
+        )
+        self.wait()
+
+        s_lines, s_labels = self.square_dimensions
+        self.play(
+            FadeOut(s_lines),
+            FadeOut(radius),
+            FadeOut(radius_label),
+            FadeOut(self.title),
+        )
+
+        self.circle_dimensions = VGroup(
+            radius, radius_label,
+        )
+
+    def show_miss_example(self):
+        square = self.square
+        point = square.get_corner(UL) + 0.5 * DR
+
+        miss_word = TextMobject("Miss!")
+        miss_word.scale(1.5)
+        miss_word.next_to(point, UP, LARGE_BUFF)
+
+        dart, dot = self.show_hit_with_dart(point)
+        self.play(FadeInFromDown(miss_word))
+        self.wait()
+        game_over = self.show_game_over()
+        self.wait()
+        self.play(
+            *map(FadeOut, [dart, dot, miss_word, game_over])
+        )
+
+    def show_shrink_rule(self):
+        circle = self.circle
+        point = 0.5 * circle.point_from_proportion(0.2)
+
+        # First example
+        self.show_full_hit_process(point)
+        self.wait()
+
+        # Close to border
+        label = TextMobject("Bad shot $\\Rightarrow$ much shrinkage")
+        label.scale(1.5)
+        label.to_edge(UP)
+
+        point = 0.98 * circle.point_from_proportion(3 / 8)
+        circle.save_state()
+        self.play(FadeInFromDown(label))
+        self.show_full_hit_process(point)
+        self.wait()
+        self.play(Restore(circle))
+
+        # Close to center
+        new_label = TextMobject("Good shot $\\Rightarrow$ less shrinkage")
+        new_label.scale(1.5)
+        new_label.to_edge(UP)
+        point = 0.2 * circle.point_from_proportion(3 / 8)
+        self.play(
+            FadeInFromDown(new_label),
+            FadeOutAndShift(label, UP),
+        )
+        self.show_full_hit_process(point)
+        self.wait()
+        self.play(FadeOut(new_label))
+
+        # Play on
+        for x in range(3):
+            r1, r2 = np.random.random(size=2)
+            point = r1 * circle.point_from_proportion(r2)
+            self.show_full_hit_process(point)
+        point = circle.get_right() + 0.5 * UR
+        self.show_miss(point)
+        self.wait()
+        self.show_game_over()
+
+
+class ShowScoring(HyperdartScene):
+    def setup(self):
+        super().setup()
+        self.add_score_counter()
+
+    def construct(self):
+        self.comment_on_score()
+        self.show_several_hits()
+
+    def comment_on_score(self):
+        score_label = self.score_label
+        comment = TextMobject("\\# Bullseyes")
+        # rect = SurroundingRectangle(comment)
+        # rect.set_stroke(width=1)
+        # comment.add(rect)
+        comment.set_color(YELLOW)
+        comment.next_to(score_label, DOWN, LARGE_BUFF)
+        comment.set_x(midpoint(
+            self.square.get_left(),
+            LEFT_SIDE,
+        )[0])
+        arrow = Arrow(
+            comment.get_top(),
+            score_label[1].get_bottom(),
+            buff=0.2,
+        )
+        arrow.match_color(comment)
+
+        self.play(
+            FadeInFromDown(comment),
+            GrowArrow(arrow),
+        )
+
+    def show_several_hits(self):
+        points = [UR, DL, 0.5 * UL, 0.5 * DR]
+        for point in points:
+            self.show_full_hit_process(point, pace="fast")
+        self.show_miss(2 * UR)
+        self.wait()
+
+    #
+    def add_score_counter(self):
+        score = Integer(0)
+        score_label = VGroup(
+            TextMobject("Score: "),
+            score
+        )
+        score_label.arrange(RIGHT, aligned_edge=DOWN)
+        score_label.scale(1.5)
+        score_label.to_corner(UL)
+
+        self.add(score_label)
+
+        self.score = score
+        self.score_label = score_label
+
+    def increment_score(self):
+        score = self.score
+        new_score = score.copy()
+        new_score.increment_value(1)
+        self.play(
+            FadeOutAndShift(score, UP),
+            FadeInFrom(new_score, DOWN),
+            run_time=1,
+        )
+        self.remove(new_score)
+        score.increment_value()
+        score.move_to(new_score)
+        self.add(score)
+
+    def show_hit(self, point, *args, **kwargs):
+        result = super().show_hit(point, *args, **kwargs)
+        if self.is_inside(point):
+            self.increment_score()
+        return result
+
+    def show_hit_with_dart(self, point, *args, **kwargs):
+        result = super().show_hit_with_dart(point, *args, **kwargs)
+        if self.is_inside(point):
+            self.increment_score()
+        return result
+
+
+class ShowSeveralRounds(ShowScoring):
+    CONFIG = {
+        "n_rounds": 5,
+    }
+
+    def construct(self):
+        for x in range(self.n_rounds):
+            self.show_single_round()
+            self.reset_board()
+
+    def show_single_round(self, pace="fast"):
+        while True:
+            point = self.get_random_point()
+            if self.is_inside(point):
+                self.show_full_hit_process(point, pace=pace)
+            else:
+                to_fade = self.show_miss(point)
+                self.wait(0.5)
+                self.play(
+                    ShowCreationThenFadeAround(self.score_label),
+                    FadeOut(to_fade)
+                )
+                return
+
+    def reset_board(self):
+        score = self.score
+        new_score = score.copy()
+        new_score.set_value(0)
+        self.play(
+            self.circle.match_width, self.square,
+            FadeOutAndShift(score, UP),
+            FadeInFrom(new_score, DOWN),
+        )
+        score.set_value(0)
+        self.add(score)
+        self.remove(new_score)
+
+
+class ShowSeveralRoundsQuickly(ShowSeveralRounds):
+    CONFIG = {
+        "n_rounds": 15,
+    }
+
+    def show_full_hit_process(self, point, *args, **kwargs):
+        lines = self.get_all_hit_lines(point)
+
+        dart = self.show_hit_with_dart(point)
+        self.add(lines)
+        self.score.increment_value(1)
+        to_fade = self.show_circle_shrink(lines[1], pace="fast")
+        to_fade.add(*lines, *dart)
+        self.play(FadeOut(to_fade), run_time=0.5)
+
+    def increment_score(self):
+        pass  # Handled elsewhere
+
+
+class ShowSeveralRoundsVeryQuickly(ShowSeveralRoundsQuickly):
+    def construct(self):
+        pass
+
+
+class ShowUniformDistribution(HyperdartScene):
+    CONFIG = {
+        "dart_sound": "dart_high",
+        "n_points": 1000,
+    }
+
+    def construct(self):
+        self.add_title()
+        self.show_random_points()
+        self.exchange_titles()
+        self.show_random_points()
+
+    def get_square(self):
+        return super().get_square().to_edge(DOWN)
+
+    def add_title(self):
+        # square = self.square
+        title = TextMobject("All points in the square are equally likely")
+        title.scale(1.5)
+        title.to_edge(UP)
+
+        new_title = TextMobject("``Uniform distribution'' on the square")
+        new_title.scale(1.5)
+        new_title.to_edge(UP)
+
+        self.play(FadeInFromDown(title))
+
+        self.title = title
+        self.new_title = new_title
+
+    def show_random_points(self):
+        points = self.get_random_points(self.n_points)
+        dots = VGroup(*[
+            Dot(point, radius=0.02)
+            for point in points
+        ])
+        dots.set_fill(opacity=0.75)
+
+        run_time = 5
+        self.play(LaggedStartMap(
+            FadeInFromLarge, dots,
+            run_time=run_time,
+        ))
+        for x in range(1000):
+            self.add_dart_sound(
+                time_offset=-run_time * np.random.random(),
+                gain=-10,
+                gain_to_background=-5,
+            )
+        self.wait()
+
+    def exchange_titles(self):
+        self.play(
+            FadeInFromDown(self.new_title),
+            FadeOutAndShift(self.title, UP),
+        )
+
+
+class ExpectedScoreEqualsQMark(Scene):
+    def construct(self):
+        equation = TextMobject(
+            "\\textbf{E}[Score] = ???",
+            tex_to_color_map={
+                "???": YELLOW,
+            }
+        )
+        aka = TextMobject("a.k.a. Long-term average")
+        aka.next_to(equation, DOWN)
+
+        self.play(Write(equation))
+        self.wait(2)
+        self.play(FadeInFrom(aka, UP))
+        self.wait()
+
+
+class ScoreHistogram(Scene):
+    CONFIG = {
+        "axes_config": {
+            ""
+        }
+    }
+
+    def construct(self):
+        self.add_axes()
+        self.add_score_label()
+        self.setup_histogram()
+        self.show_many_runs()
+
+    def add_axes(self):
+        axes = Axes(**self.axes_config)
+
+    def add_score_label(self):
+        pass
+
+    def setup_histogram(self):
+        pass
+
+    def show_many_runs(self):
+        pass
+
+
+    #
+    def add_one_run(self, animate=True):
+        pass
+
+    def get_random_score(self):
+        pass

manimlib/animation/composition.py

@@ -33,6 +33,7 @@ class AnimationGroup(Animation):
             self.group = Group(*remove_list_redundancies(
                 [anim.mobject for anim in animations]
             ))
+        self.init_run_time()
         Animation.__init__(self, self.group, **kwargs)
 
     def get_all_mobjects(self):
@@ -41,7 +42,7 @@ class AnimationGroup(Animation):
     def begin(self):
         for anim in self.animations:
             anim.begin()
-        self.init_run_time()
+        # self.init_run_time()
 
     def finish(self):
         for anim in self.animations:

manimlib/animation/creation.py

@@ -1,5 +1,7 @@
 from manimlib.animation.animation import Animation
+from manimlib.animation.composition import Succession
 from manimlib.mobject.types.vectorized_mobject import VMobject
+from manimlib.mobject.mobject import Group
 from manimlib.utils.bezier import integer_interpolate
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.rate_functions import linear
@@ -7,6 +9,7 @@ from manimlib.utils.rate_functions import double_smooth
 from manimlib.utils.rate_functions import smooth
 
 import numpy as np
+import itertools as it
 
 
 class ShowPartial(Animation):
@@ -132,4 +135,42 @@ class ShowIncreasingSubsets(Animation):
     def interpolate_mobject(self, alpha):
         n_submobs = len(self.all_submobs)
         index = int(self.int_func(alpha * n_submobs))
+        self.update_submobject_list(index)
+
+    def update_submobject_list(self, index):
         self.mobject.submobjects = self.all_submobs[:index]
+
+
+class ShowSubmobjectsOneByOne(ShowIncreasingSubsets):
+    def __init__(self, group, **kwargs):
+        new_group = Group(*group)
+        super().__init__(new_group, **kwargs)
+
+    def update_submobject_list(self, index):
+        # N = len(self.all_submobs)
+        if index == 0:
+            self.mobject.submobjects = []
+        else:
+            self.mobject.submobjects = self.all_submobs[index - 1]
+
+
+# TODO, this is broken...
+class AddTextWordByWord(Succession):
+    CONFIG = {
+        # If given a value for run_time, it will
+        # override the time_per_char
+        "run_time": None,
+        "time_per_char": 0.06,
+    }
+
+    def __init__(self, text_mobject, **kwargs):
+        digest_config(self, kwargs)
+        tpc = self.time_per_char
+        anims = it.chain(*[
+            [
+                ShowIncreasingSubsets(word, run_time=tpc * len(word)),
+                Animation(word, run_time=0.005 * len(word)**1.5),
+            ]
+            for word in text_mobject
+        ])
+        super().__init__(*anims, **kwargs)

manimlib/for_3b1b_videos/common_scenes.py

@@ -154,8 +154,7 @@ class PatreonEndScreen(PatreonThanks, PiCreatureScene):
         "randomize_order": True,
         "capitalize": True,
         "name_y_spacing": 0.7,
-        # "thanks_words": "Funded by the community, with special thanks to:",
+        "thanks_words": "My thanks to all the patrons among you",
-        "thanks_words": "Early access, name in credits and more at 3b1b.org/support",
     }
 
     def construct(self):
@@ -245,7 +244,7 @@ class PatreonEndScreen(PatreonThanks, PiCreatureScene):
         columns.next_to(underline, DOWN, buff=2)
 
         columns.generate_target()
-        columns.target.to_edge(DOWN, buff=2)
+        columns.target.to_edge(DOWN, buff=4)
         vect = columns.target.get_center() - columns.get_center()
         distance = get_norm(vect)
         wait_time = 20
@@ -259,11 +258,15 @@ class PatreonEndScreen(PatreonThanks, PiCreatureScene):
         self.wait(wait_time)
 
     def modify_patron_name(self, name):
-        if name.lower() == "RedAgent14".lower():
+        modification_map = {
-            return "Brian Shepetofsky"
+            "RedAgent14": "Brian Shepetofsky",
-        elif name.lower() == "DeathByShrimp".lower():
+            "DeathByShrimp": "Henry Bresnahan",
-            return "Henry Bresnahan"
+            "akostrikov": "Aleksandr Kostrikov",
-
+            "Jacob Baxter": "Will Fleshman",
+        }
+        for n1, n2 in modification_map.items():
+            if name.lower() == n1.lower():
+                return n2
         return name
 
 

manimlib/mobject/geometry.py

@@ -202,8 +202,6 @@ class TipableVMobject(VMobject):
         return get_norm(start - end)
 
 
-
-
 class Arc(TipableVMobject):
     CONFIG = {
         "radius": 1.0,

manimlib/mobject/types/point_cloud_mobject.py

@@ -50,6 +50,15 @@ class PMobject(Mobject):
         self.color = color
         return self
 
+    def get_stroke_width(self):
+        return self.stroke_width
+
+    def set_stroke_width(self, width, family=True):
+        mobs = self.family_members_with_points() if family else [self]
+        for mob in mobs:
+            mob.stroke_width = width
+        return self
+
     # def set_color_by_gradient(self, start_color, end_color):
     def set_color_by_gradient(self, *colors):
         self.rgbas = np.array(list(map(
@@ -158,6 +167,12 @@ class PMobject(Mobject):
         self.rgbas = interpolate(
             mobject1.rgbas, mobject2.rgbas, alpha
         )
+        self.set_stroke_width(interpolate(
+            mobject1.get_stroke_width(),
+            mobject2.get_stroke_width(),
+            alpha,
+        ))
+        return self
 
     def pointwise_become_partial(self, mobject, a, b):
         lower_index, upper_index = [
@@ -206,6 +221,14 @@ class Mobject2D(PMobject):
         Mobject.__init__(self, **kwargs)
 
 
+class PGroup(PMobject):
+    def __init__(self, *pmobs, **kwargs):
+        if not all([isinstance(m, PMobject) for m in pmobs]):
+            raise Exception("All submobjects must be of type PMobject")
+        super().__init__(**kwargs)
+        self.add(*pmobs)
+
+
 class PointCloudDot(Mobject1D):
     CONFIG = {
         "radius": 0.075,

manimlib/scene/scene.py

@@ -543,6 +543,8 @@ class Scene(Container):
             self.file_writer.write_frame(frame)
 
     def add_sound(self, sound_file, time_offset=0, gain=None, **kwargs):
+        if self.skip_animations:
+            return
         time = self.get_time() + time_offset
         self.file_writer.add_sound(sound_file, time, gain, **kwargs)
 

old_projects/name_animation.py

@@ -88,7 +88,9 @@ class NameAnimationScene(Scene):
         return self.animated_name.replace(" ", "") + "Animation"
 
 
-names = []
+names = [
+    "Happy 18th Birthday\\\\Pranavi Hiremath!"
+]
 
 if __name__ == "__main__":
     for name in names:

stage_scenes.py

@@ -45,7 +45,7 @@ def stage_scenes(module_name):
     animation_dir = os.path.join(
         os.path.expanduser('~'),
         "Dropbox (3Blue1Brown)/3Blue1Brown Team Folder/videos",
-        "windmill", "1440p60"
+        "spirals", "1440p60"
     )
     # 
     files = os.listdir(animation_dir)