Merge branch 'master' into master

Dockerfile

@@ -1,37 +1,24 @@
 FROM ubuntu:18.04
 ENV DEBIAN_FRONTEND noninteractive
-
 RUN apt-get update -qqy
 RUN apt-get install -qqy --no-install-recommends apt-utils
-
 WORKDIR /root
-RUN apt-get install -qqy build-essential libsqlite3-dev sqlite3 bzip2 \
+RUN apt-get install --no-install-recommends -qqy build-essential libsqlite3-dev sqlite3 bzip2 \
-                         libbz2-dev zlib1g-dev libssl-dev openssl libgdbm-dev \
+libbz2-dev zlib1g-dev libssl-dev openssl libgdbm-dev \
-                         libgdbm-compat-dev liblzma-dev libreadline-dev \
+libgdbm-compat-dev liblzma-dev libreadline-dev \
-                         libncursesw5-dev libffi-dev uuid-dev
+libncursesw5-dev libffi-dev uuid-dev wget ffmpeg apt-transport-https texlive-latex-base \
-RUN apt-get install -qqy wget
+texlive-full texlive-fonts-extra sox git libcairo2-dev libjpeg-dev libgif-dev && rm -rf /var/lib/apt/lists/*
 RUN wget -q https://www.python.org/ftp/python/3.7.0/Python-3.7.0.tgz
 RUN tar -xf Python-3.7.0.tgz
 WORKDIR Python-3.7.0
 RUN ./configure > /dev/null && make -s && make -s install
 RUN python3 -m pip install --upgrade pip
-RUN apt-get install -qqy libcairo2-dev libjpeg-dev libgif-dev
 COPY requirements.txt requirements.txt
 RUN python3 -m pip install -r requirements.txt
 RUN rm requirements.txt
 WORKDIR /root
 RUN rm -rf Python-3.7.0*
-
-RUN apt-get install -qqy ffmpeg
-
 ENV TZ=America/Los_Angeles
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
-RUN apt-get install -qqy apt-transport-https
-RUN apt-get install -qqy texlive-latex-base 
-RUN apt-get install -qqy texlive-full
-RUN apt-get install -qqy texlive-fonts-extra
-RUN apt-get install -qqy sox
-RUN apt-get install -qqy git
-
 ENV DEBIAN_FRONTEND teletype
 ENTRYPOINT ["/bin/bash"]

active_projects/clacks.py

@@ -3,34 +3,75 @@ import subprocess
 from pydub import AudioSegment
 
 
-MIN_TIME_BETWEEN_FLASHES = 0.004
+class Block(Square):
+    CONFIG = {
+        "mass": 1,
+        "velocity": 0,
+        "width": None,
+        "label_text": None,
+        "label_scale_value": 0.8,
+        "fill_opacity": 1,
+        "stroke_width": 3,
+        "stroke_color": WHITE,
+        "fill_color": None,
+        "sheen_direction": UL,
+        "sheen": 0.5,
+        "sheen_direction": UL,
+    }
+
+    def __init__(self, **kwargs):
+        digest_config(self, kwargs)
+        if self.width is None:
+            self.width = self.mass_to_width(self.mass)
+        if self.fill_color is None:
+            self.fill_color = self.mass_to_color(self.mass)
+        if self.label_text is None:
+            self.label_text = self.mass_to_label_text(self.mass)
+        Square.__init__(self, side_length=self.width, **kwargs)
+        self.label = self.get_label()
+        self.add(self.label)
+
+    def get_label(self):
+        label = TextMobject(self.label_text)
+        label.scale(self.label_scale_value)
+        label.next_to(self, UP, SMALL_BUFF)
+        return label
+
+    def get_points_defining_boundary(self):
+        return self.points
+
+    def mass_to_color(self, mass):
+        colors = [
+            LIGHT_GREY,
+            BLUE_B,
+            BLUE_D,
+            BLUE_E,
+            BLUE_E,
+            DARK_GREY,
+            DARK_GREY,
+            BLACK,
+        ]
+        index = min(int(np.log10(mass)), len(colors) - 1)
+        return colors[index]
+
+    def mass_to_width(self, mass):
+        return 1 + 0.25 * np.log10(mass)
+
+    def mass_to_label_text(self, mass):
+        return "{:,}\\,kg".format(int(mass))
 
 
 class SlidingBlocks(VGroup):
     CONFIG = {
         "block1_config": {
-            "mass": 1,
-            "velocity": -2,
             "distance": 7,
-            "width": None,
+            "mass": 1e6,
-            "color": None,
+            "velocity": -2,
-            "label_text": None,
         },
         "block2_config": {
+            "distance": 3,
             "mass": 1,
             "velocity": 0,
-            "distance": 3,
-            "width": None,
-            "color": None,
-            "label_text": None,
-        },
-        "block_style": {
-            "fill_opacity": 1,
-            "stroke_width": 3,
-            "stroke_color": WHITE,
-            "sheen_direction": UL,
-            "sheen_factor": 0.5,
-            "sheen_direction": UL,
         },
         "collect_clack_data": True,
     }
@@ -54,30 +95,13 @@ class SlidingBlocks(VGroup):
         if self.collect_clack_data:
             self.clack_data = self.get_clack_data()
 
-    def get_block(self, mass, distance, velocity, width, color, label_text):
+    def get_block(self, distance, **kwargs):
-        if width is None:
+        block = Block(**kwargs)
-            width = self.mass_to_width(mass)
-        if color is None:
-            color = self.mass_to_color(mass)
-        if label_text is None:
-            label_text = "{:,}\\,kg".format(int(mass))
-        block = Square(side_length=width)
-        block.mass = mass
-        block.velocity = velocity
-
-        style = dict(self.block_style)
-        style["fill_color"] = color
-
-        block.set_style(**style)
         block.move_to(
             self.floor.get_top()[1] * UP +
             (self.wall.get_right()[0] + distance) * RIGHT,
             DL,
         )
-        label = block.label = TextMobject(label_text)
-        label.scale(0.8)
-        label.next_to(block, UP, SMALL_BUFF)
-        block.add(label)
         return block
 
     def get_phase_space_point_tracker(self):
@@ -104,36 +128,6 @@ class SlidingBlocks(VGroup):
         )
         self.update_blocks_from_phase_space_point_tracker()
 
-    def old_update_positions(self, dt):
-        # Based on velocity diagram bouncing...didn't work for
-        # large masses, due to frame rate mismatch
-        blocks = self.submobjects
-        for block in blocks:
-            block.shift(block.velocity * dt * RIGHT)
-        if blocks[0].get_left()[0] < blocks[1].get_right()[0]:
-            # Two blocks collide
-            m1 = blocks[0].mass
-            m2 = blocks[1].mass
-            v1 = blocks[0].velocity
-            v2 = blocks[1].velocity
-            v_phase_space_point = np.array([
-                np.sqrt(m1) * v1, -np.sqrt(m2) * v2
-            ])
-            angle = 2 * np.arctan(np.sqrt(m2 / m1))
-            new_vps_point = rotate_vector(v_phase_space_point, angle)
-            for block, value in zip(blocks, new_vps_point):
-                block.velocity = value / np.sqrt(block.mass)
-            blocks[1].move_to(blocks[0].get_corner(DL), DR)
-            self.surrounding_scene.clack(blocks[0].get_left())
-        if blocks[1].get_left()[0] < self.wall.get_right()[0]:
-            # Second block hits wall
-            blocks[1].velocity *= -1
-            blocks[1].move_to(self.wall.get_corner(DR), DL)
-            if blocks[0].get_left()[0] < blocks[1].get_right()[0]:
-                blocks[0].move_to(blocks[1].get_corner(DR), DL)
-            self.surrounding_scene.clack(blocks[1].get_left())
-        return self
-
     def update_blocks_from_phase_space_point_tracker(self):
         block1, block2 = self.block1, self.block2
 
@@ -199,23 +193,6 @@ class SlidingBlocks(VGroup):
             clack_data.append((location, time))
         return clack_data
 
-    def mass_to_color(self, mass):
-        colors = [
-            LIGHT_GREY,
-            BLUE_B,
-            BLUE_D,
-            BLUE_E,
-            BLUE_E,
-            DARK_GREY,
-            DARK_GREY,
-            BLACK,
-        ]
-        index = min(int(np.log10(mass)), len(colors) - 1)
-        return colors[index]
-
-    def mass_to_width(self, mass):
-        return 1 + 0.25 * np.log10(mass)
-
 
 class ClackFlashes(ContinualAnimation):
     CONFIG = {
@@ -225,6 +202,7 @@ class ClackFlashes(ContinualAnimation):
             "flash_radius": 0.2,
         },
         "start_up_time": 0,
+        "min_time_between_flashes": 1 / 30,
     }
 
     def __init__(self, clack_data, **kwargs):
@@ -233,7 +211,7 @@ class ClackFlashes(ContinualAnimation):
         group = Group()
         last_time = 0
         for location, time in clack_data:
-            if (time - last_time) < MIN_TIME_BETWEEN_FLASHES:
+            if (time - last_time) < self.min_time_between_flashes:
                 continue
             last_time = time
             flash = Flash(location, **self.flash_config)
@@ -256,6 +234,33 @@ class ClackFlashes(ContinualAnimation):
                     self.mobject.remove(flash.mobject)
 
 
+class Wall(Line):
+    CONFIG = {
+        "tick_spacing": 0.5,
+        "tick_length": 0.25,
+        "tick_style": {
+            "stroke_width": 1,
+            "stroke_color": WHITE,
+        },
+    }
+
+    def __init__(self, height, **kwargs):
+        Line.__init__(self, ORIGIN, height * UP, **kwargs)
+        self.height = height
+        self.ticks = self.get_ticks()
+        self.add(self.ticks)
+
+    def get_ticks(self):
+        n_lines = int(self.height / self.tick_spacing)
+        lines = VGroup(*[
+            Line(ORIGIN, self.tick_length * UR).shift(n * self.tick_spacing * UP)
+            for n in range(n_lines)
+        ])
+        lines.set_style(**self.tick_style)
+        lines.move_to(self, DR)
+        return lines
+
+
 class BlocksAndWallScene(Scene):
     CONFIG = {
         "include_sound": True,
@@ -268,6 +273,8 @@ class BlocksAndWallScene(Scene):
         "counter_label": "\\# Collisions: ",
         "collision_sound": "clack.wav",
         "show_flash_animations": True,
+        "min_time_between_sounds": 0.004,
+        "allow_sound": True,
     }
 
     def setup(self):
@@ -320,16 +327,10 @@ class BlocksAndWallScene(Scene):
         self.counter_mob = counter_mob
 
     def get_wall(self):
-        wall = Line(self.floor_y * UP, FRAME_HEIGHT * UP / 2)
+        height = (FRAME_HEIGHT / 2) - self.floor_y
+        wall = Wall(height=height)
         wall.shift(self.wall_x * RIGHT)
-        lines = VGroup(*[
+        wall.to_edge(UP, buff=0)
-            Line(ORIGIN, 0.25 * UR)
-            for x in range(self.n_wall_ticks)
-        ])
-        lines.set_stroke(width=1)
-        lines.arrange_submobjects(UP, buff=MED_SMALL_BUFF)
-        lines.move_to(wall, DR)
-        wall.add(lines)
         return wall
 
     def get_floor(self):
@@ -359,7 +360,7 @@ class BlocksAndWallScene(Scene):
         total_time = max(times) + 1
         clacks = AudioSegment.silent(int(1000 * total_time))
         last_position = 0
-        min_diff = int(1000 * MIN_TIME_BETWEEN_FLASHES)
+        min_diff = int(1000 * self.min_time_between_sounds)
         for time in times:
             position = int(1000 * time)
             d_position = position - last_position
@@ -583,8 +584,7 @@ class BlocksAndWallExample(BlocksAndWallScene):
     CONFIG = {
         "sliding_blocks_config": {
             "block1_config": {
-                # "mass": 1e0,
+                "mass": 1e0,
-                "mass": 64,
                 "velocity": -2,
             }
         },
@@ -927,7 +927,7 @@ class PiComputingAlgorithmsAxes(Scene):
             lag_ratio=0.4,
         ))
         self.wait()
-        self.play(CircleThenFadeAround(algorithms[-1][0]))
+        self.play(ShowCreationThenFadeAround(algorithms[-1][0]))
 
     def get_machin_like_formula(self):
         formula = TexMobject(
@@ -1152,7 +1152,7 @@ class CompareToGalacticMass(Scene):
                     "velocity": -0.01,
                     "distance": 4.5,
                     "label_text": "$100^{(20 - 1)}$ kg",
-                    "color": BLACK,
+                    "fill_color": BLACK,
                 },
                 "block2_config": {
                     "distance": 1,

manimlib/animation/creation.py

@@ -113,6 +113,17 @@ class Write(DrawBorderThenFill):
         else:
             self.run_time = 2
 
+
+class ShowIncreasingSubsets(Animation):
+    def __init__(self, group, **kwargs):
+        self.all_submobs = group.submobjects
+        Animation.__init__(self, group, **kwargs)
+
+    def update_mobject(self, alpha):
+        n_submobs = len(self.all_submobs)
+        index = int(alpha * n_submobs)
+        self.mobject.submobjects = self.all_submobs[:index]
+
 # Fading
 
 
@@ -203,6 +214,7 @@ class VFadeIn(Animation):
     to mobjects while they are being animated in some other way (e.g. shifting
     then) in a way that does not work with FadeIn and FadeOut
     """
+
     def update_submobject(self, submobject, starting_submobject, alpha):
         submobject.set_stroke(
             opacity=interpolate(0, starting_submobject.get_stroke_opacity(), alpha)

manimlib/animation/indication.py

@@ -24,6 +24,7 @@ from manimlib.utils.rate_functions import smooth
 from manimlib.utils.rate_functions import squish_rate_func
 from manimlib.utils.rate_functions import there_and_back
 from manimlib.utils.rate_functions import wiggle
+from manimlib.utils.rate_functions import double_smooth
 
 
 class FocusOn(Transform):
@@ -143,6 +144,20 @@ class ShowCreationThenDestruction(ShowPassingFlash):
     }
 
 
+class ShowCreationThenFadeOut(Succession):
+    CONFIG = {
+        "remover": True,
+    }
+
+    def __init__(self, mobject, **kwargs):
+        Succession.__init__(
+            self,
+            ShowCreation, mobject,
+            FadeOut, mobject,
+            **kwargs
+        )
+
+
 class AnimationOnSurroundingRectangle(AnimationGroup):
     CONFIG = {
         "surrounding_rectangle_config": {},
@@ -174,7 +189,7 @@ class ShowCreationThenDestructionAround(AnimationOnSurroundingRectangle):
     }
 
 
-class CircleThenFadeAround(AnimationOnSurroundingRectangle):
+class ShowCreationThenFadeAround(AnimationOnSurroundingRectangle):
     CONFIG = {
         "rect_to_animation": lambda rect: Succession(
             ShowCreation, rect,

manimlib/camera/camera.py

@@ -392,7 +392,10 @@ class Camera(object):
             vmobject
         )
         ctx.set_line_width(
-            width * self.cairo_line_width_multiple
+            width * self.cairo_line_width_multiple *
+            # This ensures lines have constant width
+            # as you zoom in on them.
+            (self.get_frame_width() / FRAME_WIDTH)
         )
         ctx.stroke_preserve()
         return self

manimlib/config.py

@@ -19,32 +19,92 @@ def parse_cli():
         )
         parser.add_argument(
             "scene_names",
-            nargs="+",
+            nargs="*",
             help="Name of the Scene class you want to see",
         )
-        optional_args = [
+        parser.add_argument(
-            ("-p", "--preview"),
+            "-p", "--preview",
-            ("-w", "--write_to_movie"),
+            action="store_true",
-            ("-s", "--show_last_frame"),
+            help="Automatically open movie file once its done",
-            ("-l", "--low_quality"),
+        ),
-            ("-m", "--medium_quality"),
+        parser.add_argument(
-            ("-g", "--save_pngs"),
+            "-w", "--write_to_movie",
-            ("-f", "--show_file_in_finder"),
+            action="store_true",
-            ("-t", "--transparent"),
+            help="Render the scene as a movie file",
-            ("-q", "--quiet"),
+        ),
-            ("-a", "--write_all")
+        parser.add_argument(
-        ]
+            "-s", "--show_last_frame",
-        for short_arg, long_arg in optional_args:
+            action="store_true",
-            parser.add_argument(short_arg, long_arg, action="store_true")
+            help="Save the last frame and open the image file",
-        parser.add_argument("-o", "--output_file_name")
+        ),
-        parser.add_argument("-n", "--start_at_animation_number")
+        parser.add_argument(
-        parser.add_argument("-r", "--resolution")
+            "-l", "--low_quality",
-        parser.add_argument("-c", "--color")
+            action="store_true",
+            help="Render at a low quality (for faster rendering)",
+        ),
+        parser.add_argument(
+            "-m", "--medium_quality",
+            action="store_true",
+            help="Render at a medium quality",
+        ),
+        parser.add_argument(
+            "-g", "--save_pngs",
+            action="store_true",
+            help="Save each frame as a png",
+        ),
+        parser.add_argument(
+            "-f", "--show_file_in_finder",
+            action="store_true",
+            help="Show the output file in finder",
+        ),
+        parser.add_argument(
+            "-t", "--transparent",
+            action="store_true",
+            help="Render to a movie file with an alpha channel",
+        ),
+        parser.add_argument(
+            "-q", "--quiet",
+            action="store_true",
+            help="",
+        ),
+        parser.add_argument(
+            "-a", "--write_all",
+            action="store_true",
+            help="Write all the scenes from a file",
+        ),
+        parser.add_argument(
+            "-o", "--output_file_name",
+            nargs=1,
+            help="Specify the name of the output file, if"
+                 "it should be different from the scene class name",
+        )
+        parser.add_argument(
+            "-n", "--start_at_animation_number",
+            help="Start rendering not from the first animation, but"
+                 "from another, specified by its index.  If you pass"
+                 "in two comma separated values, e.g. \"3,6\", it will end"
+                 "the rendering at the second value",
+        )
+        parser.add_argument(
+            "-r", "--resolution",
+            help="Resolution, passed as \"height,width\"",
+        )
+        parser.add_argument(
+            "-c", "--color",
+            help="Background color",
+        )
         parser.add_argument(
             "--sound",
             action="store_true",
             help="Play a success/failure sound",
         )
+        parser.add_argument(
+            "--leave_progress_bars",
+            action="store_true",
+            help="Leave progress bars displayed in terminal",
+        )
+
+        # For live streaming
         module_location.add_argument(
             "--livestream",
             action="store_true",
@@ -129,6 +189,7 @@ def get_configuration(args):
         "start_at_animation_number": args.start_at_animation_number,
         "end_at_animation_number": None,
         "sound": args.sound,
+        "leave_progress_bars": args.leave_progress_bars
     }
 
     # Camera configuration

manimlib/extract_scene.py

@@ -133,7 +133,8 @@ def main(config):
             "movie_file_extension",
             "start_at_animation_number",
             "end_at_animation_number",
-            "output_file_name"
+            "output_file_name",
+            "leave_progress_bars",
         ]
     ])
     if config["save_pngs"]:

manimlib/for_3b1b_videos/pi_creature_scene.py

@@ -298,7 +298,7 @@ class TeacherStudentsScene(PiCreatureScene):
                 "raise_left_hand",
             ])
             kwargs["target_mode"] = target_mode
-        student = self.get_students()[kwargs.get("student_index", 1)]
+        student = self.get_students()[kwargs.get("student_index", 2)]
         return self.pi_creature_says(
             student, *content, **kwargs
         )
@@ -309,7 +309,7 @@ class TeacherStudentsScene(PiCreatureScene):
         )
 
     def student_thinks(self, *content, **kwargs):
-        student = self.get_students()[kwargs.get("student_index", 1)]
+        student = self.get_students()[kwargs.get("student_index", 2)]
         return self.pi_creature_thinks(student, *content, **kwargs)
 
     def change_all_student_modes(self, mode, **kwargs):

manimlib/mobject/coordinate_systems.py

@@ -9,6 +9,7 @@ from manimlib.mobject.svg.tex_mobject import TexMobject
 from manimlib.mobject.types.vectorized_mobject import VGroup
 from manimlib.mobject.types.vectorized_mobject import VMobject
 from manimlib.utils.config_ops import digest_config
+from manimlib.utils.config_ops import merge_config
 from manimlib.utils.space_ops import angle_of_vector
 
 # TODO: There should be much more code reuse between Axes, NumberPlane and GraphScene
@@ -35,16 +36,21 @@ class Axes(VGroup):
 
     def __init__(self, **kwargs):
         VGroup.__init__(self, **kwargs)
-        self.x_axis = self.get_axis(self.x_min, self.x_max, self.x_axis_config)
+        x_axis_config = merge_config([
-        self.y_axis = self.get_axis(self.y_min, self.y_max, self.y_axis_config)
+            self.x_axis_config,
-        self.y_axis.rotate(np.pi / 2, about_point=ORIGIN)
+            {"x_min": self.x_min, "x_max": self.x_max},
+            self.number_line_config,
+        ])
+        y_axis_config = merge_config([
+            self.y_axis_config,
+            {"x_min": self.y_min, "x_max": self.y_max},
+            self.number_line_config,
+        ])
+        self.x_axis = NumberLine(**x_axis_config)
+        self.y_axis = NumberLine(**y_axis_config)
+        self.y_axis.rotate(90 * DEGREES, about_point=ORIGIN)
         self.add(self.x_axis, self.y_axis)
 
-    def get_axis(self, min_val, max_val, extra_config):
-        config = dict(self.number_line_config)
-        config.update(extra_config)
-        return NumberLine(x_min=min_val, x_max=max_val, **config)
-
     def coords_to_point(self, *coords):
         origin = self.x_axis.number_to_point(0)
         result = np.array(origin)

manimlib/mobject/geometry.py

@@ -23,6 +23,7 @@ class Arc(VMobject):
         "start_angle": 0,
         "num_anchors": 9,
         "anchors_span_full_range": True,
+        "arc_center": ORIGIN,
     }
 
     def __init__(self, angle, **kwargs):
@@ -50,6 +51,7 @@ class Arc(VMobject):
             anchors, handles1, handles2
         )
         self.scale(self.radius, about_point=ORIGIN)
+        self.shift(self.arc_center)
 
     def add_tip(self, tip_length=0.25, at_start=False, at_end=True):
         # clear out any old tips
@@ -166,7 +168,7 @@ class Circle(Arc):
     }
 
     def __init__(self, **kwargs):
-        Arc.__init__(self, 2 * np.pi, **kwargs)
+        Arc.__init__(self, TAU, **kwargs)
 
     def surround(self, mobject, dim_to_match=0, stretch=False, buffer_factor=1.2):
         # Ignores dim_to_match and stretch; result will always be a circle
@@ -180,6 +182,14 @@ class Circle(Arc):
             np.sqrt(mobject.get_width()**2 + mobject.get_height()**2))
         self.scale(buffer_factor)
 
+    def get_point_from_angle(self, angle):
+        start_angle = angle_of_vector(
+            self.points[0] - self.get_center()
+        )
+        return self.point_from_proportion(
+            (angle - start_angle) / TAU
+        )
+
 
 class Dot(Circle):
     CONFIG = {

manimlib/mobject/mobject.py

@@ -145,7 +145,7 @@ class Mobject(Container):
 
     # Updating
 
-    def update(self, dt):
+    def update(self, dt=0):
         for updater in self.updaters:
             num_args = get_num_args(updater)
             if num_args == 1:

manimlib/mobject/numbers.py

@@ -105,7 +105,10 @@ class DecimalNumber(VMobject):
         full_config.update(self.initial_config)
         full_config.update(config)
         new_decimal = DecimalNumber(number, **full_config)
-        new_decimal.match_height(self)
+        # new_decimal.match_height(self)
+        new_decimal.scale(
+            self[0].get_height() / new_decimal[0].get_height()
+        )
         new_decimal.move_to(self, self.edge_to_fix)
         new_decimal.match_style(self)
 
@@ -129,3 +132,6 @@ class Integer(DecimalNumber):
 
     def increment_value(self):
         self.set_value(self.get_value() + 1)
+
+    def get_value(self):
+        return int(np.round(super().get_value()))

manimlib/scene/scene.py

@@ -10,6 +10,7 @@ import warnings
 
 from tqdm import tqdm as ProgressDisplay
 import numpy as np
+from pydub import AudioSegment
 
 from manimlib.animation.animation import Animation
 from manimlib.animation.creation import Write
@@ -35,7 +36,6 @@ class Scene(Container):
         "frame_duration": LOW_QUALITY_FRAME_DURATION,
         "construct_args": [],
         "skip_animations": False,
-        "ignore_waits": False,
         "write_to_movie": False,
         "save_pngs": False,
         "pngs_mode": "RGBA",
@@ -48,6 +48,7 @@ class Scene(Container):
         "to_twitch": False,
         "twitch_key": None,
         "output_file_name": None,
+        "leave_progress_bars": False,
     }
 
     def __init__(self, **kwargs):
@@ -66,17 +67,20 @@ class Scene(Container):
             random.seed(self.random_seed)
             np.random.seed(self.random_seed)
 
+        self.init_audio()
         self.setup()
         if self.livestreaming:
             return None
         try:
             self.construct(*self.construct_args)
         except EndSceneEarlyException:
-            pass
+            if hasattr(self, "writing_process"):
+                self.writing_process.terminate()
         self.tear_down()
 
         if self.write_to_movie:
             self.combine_movie_files()
+        self.print_end_message()
 
     def handle_play_like_call(func):
         def wrapper(self, *args, **kwargs):
@@ -117,6 +121,9 @@ class Scene(Container):
             return self.output_file_name
         return str(self)
 
+    def print_end_message(self):
+        print("Played {} animations".format(self.num_plays))
+
     def set_variables_as_attrs(self, *objects, **newly_named_objects):
         """
         This method is slightly hacky, making it a little easier
@@ -135,6 +142,38 @@ class Scene(Container):
     def get_attrs(self, *keys):
         return [getattr(self, key) for key in keys]
 
+    # Sound
+    def init_audio(self):
+        self.includes_sound = False
+
+    def create_audio_segment(self):
+        self.audio_segment = AudioSegment.silent()
+
+    def add_audio_segment(self, new_segment, time_offset=0):
+        if not self.includes_sound:
+            self.includes_sound = True
+            self.create_audio_segment()
+        segment = self.audio_segment
+        overly_time = self.get_time() + time_offset
+        if overly_time < 0:
+            raise Exception("Adding sound at timestamp < 0")
+
+        curr_end = segment.duration_seconds
+        new_end = overly_time + new_segment.duration_seconds
+        diff = new_end - curr_end
+        if diff > 0:
+            segment = segment.append(
+                AudioSegment.silent(int(np.ceil(diff * 1000))),
+                crossfade=0,
+            )
+        self.audio_segment = segment.overlay(
+            new_segment, position=int(1000 * overly_time)
+        )
+
+    def add_sound(self, sound_file, time_offset=0):
+        new_segment = AudioSegment.from_file(sound_file)
+        self.add_audio_segment(new_segment, 0)
+
     # Only these methods should touch the camera
 
     def set_camera(self, camera):
@@ -386,20 +425,26 @@ class Scene(Container):
                     return mobjects[i:]
         return []
 
-    def get_time_progression(self, run_time):
+    def get_time_progression(self, run_time, n_iterations=None, override_skip_animations=False):
-        if self.skip_animations:
+        if self.skip_animations and not override_skip_animations:
             times = [run_time]
         else:
             step = self.frame_duration
             times = np.arange(0, run_time, step)
-        time_progression = ProgressDisplay(times)
+        time_progression = ProgressDisplay(
+            times, total=n_iterations,
+            leave=self.leave_progress_bars,
+        )
         return time_progression
 
+    def get_run_time(self, animations):
+        return np.max([animation.run_time for animation in animations])
+
     def get_animation_time_progression(self, animations):
-        run_time = np.max([animation.run_time for animation in animations])
+        run_time = self.get_run_time(animations)
         time_progression = self.get_time_progression(run_time)
         time_progression.set_description("".join([
-            "Animation %d: " % self.num_plays,
+            "Animation {}: ".format(self.num_plays),
             str(animations[0]),
             (", etc." if len(animations) > 1 else ""),
         ]))
@@ -498,20 +543,18 @@ class Scene(Container):
         # have to be rendered every frame
         self.update_frame(excluded_mobjects=moving_mobjects)
         static_image = self.get_frame()
-        total_run_time = 0
         for t in self.get_animation_time_progression(animations):
             for animation in animations:
                 animation.update(t / animation.run_time)
-            self.continual_update(dt=t - total_run_time)
+            self.continual_update(dt=self.frame_duration)
             self.update_frame(moving_mobjects, static_image)
             self.add_frames(self.get_frame())
-            total_run_time = t
         self.mobjects_from_last_animation = [
             anim.mobject for anim in animations
         ]
         self.clean_up_animations(*animations)
         if self.skip_animations:
-            self.continual_update(total_run_time)
+            self.continual_update(self.get_run_time(animations))
         else:
             self.continual_update(0)
 
@@ -542,15 +585,35 @@ class Scene(Container):
             return self.mobjects_from_last_animation
         return []
 
+    def get_wait_time_progression(self, duration, stop_condition):
+        if stop_condition is not None:
+            time_progression = self.get_time_progression(
+                duration,
+                n_iterations=-1,  # So it doesn't show % progress
+                override_skip_animations=True
+
+            )
+            time_progression.set_description(
+                "Waiting for {}".format(stop_condition.__name__)
+            )
+        else:
+            time_progression = self.get_time_progression(duration)
+            time_progression.set_description(
+                "Waiting {}".format(self.num_plays)
+            )
+        return time_progression
+
     @handle_play_like_call
-    def wait(self, duration=DEFAULT_WAIT_TIME):
+    def wait(self, duration=DEFAULT_WAIT_TIME, stop_condition=None):
         if self.should_continually_update():
-            total_time = 0
+            time_progression = self.get_wait_time_progression(duration, stop_condition)
-            for t in self.get_time_progression(duration):
+            for t in time_progression:
-                self.continual_update(dt=t - total_time)
+                self.continual_update(dt=self.frame_duration)
                 self.update_frame()
                 self.add_frames(self.get_frame())
-                total_time = t
+                if stop_condition and stop_condition():
+                    time_progression.close()
+                    break
         elif self.skip_animations:
             # Do nothing
             return self
@@ -561,16 +624,8 @@ class Scene(Container):
             self.add_frames(*[frame] * n_frames)
         return self
 
-    def wait_to(self, time, assert_positive=True):
+    def wait_until(self, stop_condition, max_time=60):
-        if self.ignore_waits:
+        self.wait(max_time, stop_condition=stop_condition)
-            return
-        time -= self.get_time()
-        if assert_positive:
-            assert(time >= 0)
-        elif time < 0:
-            return
-
-        self.wait(time)
 
     def force_skipping(self):
         self.original_skipping_status = self.skip_animations
@@ -647,7 +702,9 @@ class Scene(Container):
             )
         )
         temp_file_path = file_path.replace(".", "_temp.")
-        self.args_to_rename_file = (temp_file_path, file_path)
+
+        self.movie_file_path = file_path
+        self.temp_movie_file_path = temp_file_path
 
         fps = int(1 / self.frame_duration)
         height = self.camera.get_pixel_height()
@@ -693,9 +750,13 @@ class Scene(Container):
         self.writing_process.wait()
         if self.livestreaming:
             return True
-        shutil.move(*self.args_to_rename_file)
+        shutil.move(
+            self.temp_movie_file_path,
+            self.movie_file_path,
+        )
 
     def combine_movie_files(self):
+        # TODO, this could probably use a refactor
         partial_movie_file_directory = self.get_partial_movie_directory()
         kwargs = {
             "remove_non_integer_files": True,
@@ -732,19 +793,48 @@ class Scene(Container):
             '-safe', '0',
             '-i', file_list,
             '-c', 'copy',
-            '-an',  # Tells FFMPEG not to expect any audio
             '-loglevel', 'error',
             movie_file_path
         ]
+        if not self.includes_sound:
+            commands.insert(-1, '-an')
+
         combine_process = subprocess.Popen(commands)
         combine_process.wait()
         for pf_path in partial_movie_files:
             os.remove(pf_path)
         os.remove(file_list)
-        os.rmdir(partial_movie_file_directory)
-        os.rmdir(os.path.join(partial_movie_file_directory, os.path.pardir))
         print("File ready at {}".format(movie_file_path))
 
+        if self.includes_sound:
+            sound_file_path = movie_file_path.replace(
+                self.movie_file_extension, ".wav"
+            )
+            # Makes sure sound file length will match video file
+            self.add_audio_segment(AudioSegment.silent(0))
+            self.audio_segment.export(sound_file_path)
+            temp_file_path = movie_file_path.replace(".", "_temp.")
+            commands = commands = [
+                "ffmpeg",
+                "-i", movie_file_path,
+                "-i", sound_file_path,
+                '-y',  # overwrite output file if it exists
+                "-c:v", "copy", "-c:a", "aac",
+                '-loglevel', 'error',
+                "-shortest",
+                "-strict", "experimental",
+                temp_file_path,
+            ]
+            subprocess.call(commands)
+            shutil.move(temp_file_path, movie_file_path)
+            # subprocess.call(["rm", self.temp_movie_file_path])
+            subprocess.call(["rm", sound_file_path])
+
+        print("\nAnimation ready at {}\n".format(movie_file_path))
+
+    # TODO, this doesn't belong in Scene, but should be
+    # part of some more specialized subclass optimized
+    # for livestreaming
     def tex(self, latex):
         eq = TextMobject(latex)
         anims = []

old_projects/borsuk_addition.py

@@ -527,9 +527,9 @@ class FunctionGInSymbols(Scene):
             VGroup(seeking_text, g_equals_zero).shift, 1.5 * DOWN
         )
         self.wait()
-        self.play(CircleThenFadeAround(g_of_neg_p[2]))
+        self.play(ShowCreationThenFadeAround(g_of_neg_p[2]))
         self.wait()
-        self.play(CircleThenFadeAround(neg_g_of_p))
+        self.play(ShowCreationThenFadeAround(neg_g_of_p))
         self.wait()
         self.play(neg_g_of_p.restore)
         rects = VGroup(*map(SurroundingRectangle, [f_of_p, f_of_neg_p]))

old_projects/dandelin.py

@@ -387,7 +387,7 @@ class ShowArrayOfEccentricities(Scene):
             e_copy.set_color(RED)
             self.play(ShowCreation(e_copy))
             self.play(
-                CircleThenFadeAround(
+                ShowCreationThenFadeAround(
                     eccentricity_labels[i],
                 ),
                 FadeOut(e_copy)

old_projects/div_curl.py

@@ -857,7 +857,7 @@ class CylinderModel(Scene):
         self.wait()
         self.play(
             movers.apply_complex_function, joukowsky_map,
-            CircleThenFadeAround(self.func_label),
+            ShowCreationThenFadeAround(self.func_label),
             run_time=2
         )
         self.add(self.get_stream_lines_animation(stream_lines))

old_projects/for_flammy.py

@@ -310,9 +310,9 @@ class IntegralSymbols(Scene):
 
         self.play(FadeInFrom(rhs, 4 * LEFT))
         self.wait()
-        self.play(CircleThenFadeAround(rhs[1]))
+        self.play(ShowCreationThenFadeAround(rhs[1]))
         self.wait()
-        self.play(CircleThenFadeAround(rhs[2:]))
+        self.play(ShowCreationThenFadeAround(rhs[2:]))
         self.wait()
         self.play(
             GrowFromCenter(int_brace),

old_projects/lost_lecture.py

@@ -3360,7 +3360,7 @@ class ShowEqualAngleSlices(IntroduceShapeOfVelocities):
             delta_t_numerator.scale, 1.5, {"about_edge": DOWN},
             delta_t_numerator.set_color, YELLOW
         )
-        self.play(CircleThenFadeAround(prop_exp[:-2]))
+        self.play(ShowCreationThenFadeAround(prop_exp[:-2]))
         self.play(
             delta_t_numerator.fade, 1,
             MoveToTarget(moving_R_squared),
@@ -3447,7 +3447,7 @@ class ShowEqualAngleSlices(IntroduceShapeOfVelocities):
         polygon.set_fill(BLUE_E, opacity=0.8)
         polygon.set_stroke(WHITE, 3)
 
-        self.play(CircleThenFadeAround(v1))
+        self.play(ShowCreationThenFadeAround(v1))
         self.play(
             MoveToTarget(v1),
             GrowFromCenter(root_dot),

old_projects/quaternions.py

@@ -4182,7 +4182,7 @@ class IntroduceQuaternions(Scene):
                 FadeInFromDown(number),
                 Write(label),
             )
-            self.play(CircleThenFadeAround(
+            self.play(ShowCreationThenFadeAround(
                 number[2:],
                 surrounding_rectangle_config={"color": BLUE}
             ))
@@ -4630,7 +4630,7 @@ class BreakUpQuaternionMultiplicationInParts(Scene):
         )
         self.play(
             randy.change, "confused", rotate_words,
-            CircleThenFadeAround(rotate_words),
+            ShowCreationThenFadeAround(rotate_words),
         )
         self.play(LaggedStart(
             FadeInFrom, q_marks,

old_projects/sphere_area.py

@@ -1861,7 +1861,7 @@ class JustifyHeightSquish(MovingCameraScene):
         ))
         self.wait()
         self.play(ReplacementTransform(q_mark, alpha_label1))
-        self.play(CircleThenFadeAround(
+        self.play(ShowCreationThenFadeAround(
             equation,
             surrounding_rectangle_config={
                 "buff": 0.015,

old_projects/turbulence.py

@@ -1018,7 +1018,7 @@ class ShowNavierStokesEquations(Scene):
             FadeInFromDown(labels[0]),
             newtons_second.next_to, variables, RIGHT, LARGE_BUFF
         )
-        self.play(CircleThenFadeAround(parts[0]))
+        self.play(ShowCreationThenFadeAround(parts[0]))
         self.wait()
         self.play(LaggedStart(FadeInFrom, labels[1:]))
         self.wait(3)

requirements.txt

@@ -7,3 +7,4 @@ scipy==1.1.0
 tqdm==4.24.0
 opencv-python==3.4.2.17
 pycairo==1.17.1
+pydub==0.23.0