3b1b-manim/manimlib/scene/scene.py
Grant Sanderson f4737828f6
Video work (#2326)
* Only use -no-pdf for xelatex rendering

* Instead of tracking du and dv points on surface, track points off the surface in the normal direction

This means that surface shading will not necessarily work well for arbitrary transformations of the surface. But the existing solution was flimsy anyway, and caused annoying issues with singularity points.

* Have density of anchor points on arcs depend on arc length

* Allow for specifying true normals and orientation of Sphere

* Change miter threshold on stroke shader

* Add get_start_and_end to DashedLine

* Add min_total_width option to DecimalNumber

* Have BackgroundRectangle.set_style absorb (and ignore) added configuration

Note, this feels suboptimal

* Add LineBrace

* Update font_size adjustment in Tex

* Add scale_factor parameter to BulletedList.fade_all_but

* Minor import tweaks

* Add play_sound
2025-03-20 12:00:35 -07:00

930 lines
31 KiB
Python

from __future__ import annotations
from collections import OrderedDict
import platform
import random
import time
from functools import wraps
from contextlib import contextmanager
from contextlib import ExitStack
import numpy as np
from tqdm.auto import tqdm as ProgressDisplay
from pyglet.window import key as PygletWindowKeys
from manimlib.animation.animation import prepare_animation
from manimlib.camera.camera import Camera
from manimlib.camera.camera_frame import CameraFrame
from manimlib.config import manim_config
from manimlib.event_handler import EVENT_DISPATCHER
from manimlib.event_handler.event_type import EventType
from manimlib.logger import log
from manimlib.mobject.mobject import _AnimationBuilder
from manimlib.mobject.mobject import Group
from manimlib.mobject.mobject import Mobject
from manimlib.mobject.mobject import Point
from manimlib.mobject.types.vectorized_mobject import VGroup
from manimlib.mobject.types.vectorized_mobject import VMobject
from manimlib.scene.scene_embed import InteractiveSceneEmbed
from manimlib.scene.scene_embed import CheckpointManager
from manimlib.scene.scene_file_writer import SceneFileWriter
from manimlib.utils.dict_ops import merge_dicts_recursively
from manimlib.utils.family_ops import extract_mobject_family_members
from manimlib.utils.family_ops import recursive_mobject_remove
from manimlib.utils.iterables import batch_by_property
from manimlib.utils.sounds import play_sound
from manimlib.window import Window
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import Callable, Iterable, TypeVar, Optional
from manimlib.typing import Vect3
T = TypeVar('T')
from PIL.Image import Image
from manimlib.animation.animation import Animation
class Scene(object):
random_seed: int = 0
pan_sensitivity: float = 0.5
scroll_sensitivity: float = 20
drag_to_pan: bool = True
max_num_saved_states: int = 50
default_camera_config: dict = dict()
default_file_writer_config: dict = dict()
samples = 0
# Euler angles, in degrees
default_frame_orientation = (0, 0)
def __init__(
self,
window: Optional[Window] = None,
camera_config: dict = dict(),
file_writer_config: dict = dict(),
skip_animations: bool = False,
always_update_mobjects: bool = False,
start_at_animation_number: int | None = None,
end_at_animation_number: int | None = None,
show_animation_progress: bool = False,
leave_progress_bars: bool = False,
preview_while_skipping: bool = True,
presenter_mode: bool = False,
default_wait_time: float = 1.0,
):
self.skip_animations = skip_animations
self.always_update_mobjects = always_update_mobjects
self.start_at_animation_number = start_at_animation_number
self.end_at_animation_number = end_at_animation_number
self.show_animation_progress = show_animation_progress
self.leave_progress_bars = leave_progress_bars
self.preview_while_skipping = preview_while_skipping
self.presenter_mode = presenter_mode
self.default_wait_time = default_wait_time
self.camera_config = merge_dicts_recursively(
manim_config.camera, # Global default
self.default_camera_config, # Updated configuration that subclasses may specify
camera_config, # Updated configuration from instantiation
)
self.file_writer_config = merge_dicts_recursively(
manim_config.file_writer,
self.default_file_writer_config,
file_writer_config,
)
self.window = window
if self.window:
self.window.init_for_scene(self)
# Make sure camera and Pyglet window sync
self.camera_config["fps"] = 30
# Core state of the scene
self.camera: Camera = Camera(
window=self.window,
samples=self.samples,
**self.camera_config
)
self.frame: CameraFrame = self.camera.frame
self.frame.reorient(*self.default_frame_orientation)
self.frame.make_orientation_default()
self.file_writer = SceneFileWriter(self, **self.file_writer_config)
self.mobjects: list[Mobject] = [self.camera.frame]
self.render_groups: list[Mobject] = []
self.id_to_mobject_map: dict[int, Mobject] = dict()
self.num_plays: int = 0
self.time: float = 0
self.skip_time: float = 0
self.original_skipping_status: bool = self.skip_animations
self.undo_stack = []
self.redo_stack = []
if self.start_at_animation_number is not None:
self.skip_animations = True
if self.file_writer.has_progress_display():
self.show_animation_progress = False
# Items associated with interaction
self.mouse_point = Point()
self.mouse_drag_point = Point()
self.hold_on_wait = self.presenter_mode
self.quit_interaction = False
# Much nicer to work with deterministic scenes
if self.random_seed is not None:
random.seed(self.random_seed)
np.random.seed(self.random_seed)
def __str__(self) -> str:
return self.__class__.__name__
def get_window(self) -> Window | None:
return self.window
def run(self) -> None:
self.virtual_animation_start_time: float = 0
self.real_animation_start_time: float = time.time()
self.file_writer.begin()
self.setup()
try:
self.construct()
self.interact()
except EndScene:
pass
except KeyboardInterrupt:
# Get rid keyboard interupt symbols
print("", end="\r")
self.file_writer.ended_with_interrupt = True
self.tear_down()
def setup(self) -> None:
"""
This is meant to be implement by any scenes which
are comonly subclassed, and have some common setup
involved before the construct method is called.
"""
pass
def construct(self) -> None:
# Where all the animation happens
# To be implemented in subclasses
pass
def tear_down(self) -> None:
self.stop_skipping()
self.file_writer.finish()
if self.window:
self.window.destroy()
self.window = None
def interact(self) -> None:
"""
If there is a window, enter a loop
which updates the frame while under
the hood calling the pyglet event loop
"""
if self.window is None:
return
log.info(
"\nTips: Using the keys `d`, `f`, or `z` " +
"you can interact with the scene. " +
"Press `command + q` or `esc` to quit"
)
self.skip_animations = False
while not self.is_window_closing():
self.update_frame(1 / self.camera.fps)
def embed(
self,
close_scene_on_exit: bool = True,
show_animation_progress: bool = False,
) -> None:
if not self.window:
# Embed is only relevant for interactive development with a Window
return
self.show_animation_progress = show_animation_progress
self.stop_skipping()
self.update_frame(force_draw=True)
InteractiveSceneEmbed(self).launch()
# End scene when exiting an embed
if close_scene_on_exit:
raise EndScene()
# Only these methods should touch the camera
def get_image(self) -> Image:
if self.window is not None:
self.camera.use_window_fbo(False)
self.camera.capture(*self.render_groups)
image = self.camera.get_image()
if self.window is not None:
self.camera.use_window_fbo(True)
return image
def show(self) -> None:
self.update_frame(force_draw=True)
self.get_image().show()
def update_frame(self, dt: float = 0, force_draw: bool = False) -> None:
self.increment_time(dt)
self.update_mobjects(dt)
if self.skip_animations and not force_draw:
return
if self.is_window_closing():
raise EndScene()
if self.window and dt == 0 and not self.window.has_undrawn_event() and not force_draw:
# In this case, there's no need for new rendering, but we
# shoudl still listen for new events
self.window._window.dispatch_events()
return
self.camera.capture(*self.render_groups)
if self.window and not self.skip_animations:
vt = self.time - self.virtual_animation_start_time
rt = time.time() - self.real_animation_start_time
time.sleep(max(vt - rt, 0))
def emit_frame(self) -> None:
if not self.skip_animations:
self.file_writer.write_frame(self.camera)
# Related to updating
def update_mobjects(self, dt: float) -> None:
for mobject in self.mobjects:
mobject.update(dt)
def should_update_mobjects(self) -> bool:
return self.always_update_mobjects or any(
mob.has_updaters() for mob in self.mobjects
)
# Related to time
def get_time(self) -> float:
return self.time
def increment_time(self, dt: float) -> None:
self.time += dt
# Related to internal mobject organization
def get_top_level_mobjects(self) -> list[Mobject]:
# Return only those which are not in the family
# of another mobject from the scene
mobjects = self.get_mobjects()
families = [m.get_family() for m in mobjects]
def is_top_level(mobject):
num_families = sum([
(mobject in family)
for family in families
])
return num_families == 1
return list(filter(is_top_level, mobjects))
def get_mobject_family_members(self) -> list[Mobject]:
return extract_mobject_family_members(self.mobjects)
def assemble_render_groups(self):
"""
Rendering can be more efficient when mobjects of the
same type are grouped together, so this function creates
Groups of all clusters of adjacent Mobjects in the scene
"""
batches = batch_by_property(
self.mobjects,
lambda m: str(type(m)) + str(m.get_shader_wrapper(self.camera.ctx).get_id()) + str(m.z_index)
)
for group in self.render_groups:
group.clear()
self.render_groups = [
batch[0].get_group_class()(*batch)
for batch, key in batches
]
@staticmethod
def affects_mobject_list(func: Callable[..., T]) -> Callable[..., T]:
@wraps(func)
def wrapper(self, *args, **kwargs):
func(self, *args, **kwargs)
self.assemble_render_groups()
return self
return wrapper
@affects_mobject_list
def add(self, *new_mobjects: Mobject):
"""
Mobjects will be displayed, from background to
foreground in the order with which they are added.
"""
self.remove(*new_mobjects)
self.mobjects += new_mobjects
# Reorder based on z_index
id_to_scene_order = {id(m): idx for idx, m in enumerate(self.mobjects)}
self.mobjects.sort(key=lambda m: (m.z_index, id_to_scene_order[id(m)]))
self.id_to_mobject_map.update({
id(sm): sm
for m in new_mobjects
for sm in m.get_family()
})
return self
def add_mobjects_among(self, values: Iterable):
"""
This is meant mostly for quick prototyping,
e.g. to add all mobjects defined up to a point,
call self.add_mobjects_among(locals().values())
"""
self.add(*filter(
lambda m: isinstance(m, Mobject),
values
))
return self
@affects_mobject_list
def replace(self, mobject: Mobject, *replacements: Mobject):
if mobject in self.mobjects:
index = self.mobjects.index(mobject)
self.mobjects = [
*self.mobjects[:index],
*replacements,
*self.mobjects[index + 1:]
]
return self
@affects_mobject_list
def remove(self, *mobjects_to_remove: Mobject):
"""
Removes anything in mobjects from scenes mobject list, but in the event that one
of the items to be removed is a member of the family of an item in mobject_list,
the other family members are added back into the list.
For example, if the scene includes Group(m1, m2, m3), and we call scene.remove(m1),
the desired behavior is for the scene to then include m2 and m3 (ungrouped).
"""
to_remove = set(extract_mobject_family_members(mobjects_to_remove))
new_mobjects, _ = recursive_mobject_remove(self.mobjects, to_remove)
self.mobjects = new_mobjects
def bring_to_front(self, *mobjects: Mobject):
self.add(*mobjects)
return self
@affects_mobject_list
def bring_to_back(self, *mobjects: Mobject):
self.remove(*mobjects)
self.mobjects = list(mobjects) + self.mobjects
return self
@affects_mobject_list
def clear(self):
self.mobjects = []
return self
def get_mobjects(self) -> list[Mobject]:
return list(self.mobjects)
def get_mobject_copies(self) -> list[Mobject]:
return [m.copy() for m in self.mobjects]
def point_to_mobject(
self,
point: np.ndarray,
search_set: Iterable[Mobject] | None = None,
buff: float = 0
) -> Mobject | None:
"""
E.g. if clicking on the scene, this returns the top layer mobject
under a given point
"""
if search_set is None:
search_set = self.mobjects
for mobject in reversed(search_set):
if mobject.is_point_touching(point, buff=buff):
return mobject
return None
def get_group(self, *mobjects):
if all(isinstance(m, VMobject) for m in mobjects):
return VGroup(*mobjects)
else:
return Group(*mobjects)
def id_to_mobject(self, id_value):
return self.id_to_mobject_map[id_value]
def ids_to_group(self, *id_values):
return self.get_group(*filter(
lambda x: x is not None,
map(self.id_to_mobject, id_values)
))
def i2g(self, *id_values):
return self.ids_to_group(*id_values)
def i2m(self, id_value):
return self.id_to_mobject(id_value)
# Related to skipping
def update_skipping_status(self) -> None:
if self.start_at_animation_number is not None:
if self.num_plays == self.start_at_animation_number:
self.skip_time = self.time
if not self.original_skipping_status:
self.stop_skipping()
if self.end_at_animation_number is not None:
if self.num_plays >= self.end_at_animation_number:
raise EndScene()
def stop_skipping(self) -> None:
self.virtual_animation_start_time = self.time
self.real_animation_start_time = time.time()
self.skip_animations = False
# Methods associated with running animations
def get_time_progression(
self,
run_time: float,
n_iterations: int | None = None,
desc: str = "",
override_skip_animations: bool = False
) -> list[float] | np.ndarray | ProgressDisplay:
if self.skip_animations and not override_skip_animations:
return [run_time]
times = np.arange(0, run_time, 1 / self.camera.fps) + 1 / self.camera.fps
self.file_writer.set_progress_display_description(sub_desc=desc)
if self.show_animation_progress:
return ProgressDisplay(
times,
total=n_iterations,
leave=self.leave_progress_bars,
ascii=True if platform.system() == 'Windows' else None,
desc=desc,
bar_format="{l_bar} {n_fmt:3}/{total_fmt:3} {rate_fmt}{postfix}",
)
else:
return times
def get_run_time(self, animations: Iterable[Animation]) -> float:
return np.max([animation.get_run_time() for animation in animations])
def get_animation_time_progression(
self,
animations: Iterable[Animation]
) -> list[float] | np.ndarray | ProgressDisplay:
animations = list(animations)
run_time = self.get_run_time(animations)
description = f"{self.num_plays} {animations[0]}"
if len(animations) > 1:
description += ", etc."
time_progression = self.get_time_progression(run_time, desc=description)
return time_progression
def get_wait_time_progression(
self,
duration: float,
stop_condition: Callable[[], bool] | None = None
) -> list[float] | np.ndarray | ProgressDisplay:
kw = {"desc": f"{self.num_plays} Waiting"}
if stop_condition is not None:
kw["n_iterations"] = -1 # So it doesn't show % progress
kw["override_skip_animations"] = True
return self.get_time_progression(duration, **kw)
def pre_play(self):
if self.presenter_mode and self.num_plays == 0:
self.hold_loop()
self.update_skipping_status()
if not self.skip_animations:
self.file_writer.begin_animation()
if self.window:
self.virtual_animation_start_time = self.time
self.real_animation_start_time = time.time()
def post_play(self):
if not self.skip_animations:
self.file_writer.end_animation()
if self.preview_while_skipping and self.skip_animations and self.window is not None:
# Show some quick frames along the way
self.update_frame(dt=0, force_draw=True)
self.num_plays += 1
def begin_animations(self, animations: Iterable[Animation]) -> None:
all_mobjects = set(self.get_mobject_family_members())
for animation in animations:
animation.begin()
# Anything animated that's not already in the
# scene gets added to the scene. Note, for
# animated mobjects that are in the family of
# those on screen, this can result in a restructuring
# of the scene.mobjects list, which is usually desired.
if animation.mobject not in all_mobjects:
self.add(animation.mobject)
all_mobjects = all_mobjects.union(animation.mobject.get_family())
def progress_through_animations(self, animations: Iterable[Animation]) -> None:
last_t = 0
for t in self.get_animation_time_progression(animations):
dt = t - last_t
last_t = t
for animation in animations:
animation.update_mobjects(dt)
alpha = t / animation.run_time
animation.interpolate(alpha)
self.update_frame(dt)
self.emit_frame()
def finish_animations(self, animations: Iterable[Animation]) -> None:
for animation in animations:
animation.finish()
animation.clean_up_from_scene(self)
if self.skip_animations:
self.update_mobjects(self.get_run_time(animations))
else:
self.update_mobjects(0)
@affects_mobject_list
def play(
self,
*proto_animations: Animation | _AnimationBuilder,
run_time: float | None = None,
rate_func: Callable[[float], float] | None = None,
lag_ratio: float | None = None,
) -> None:
if len(proto_animations) == 0:
log.warning("Called Scene.play with no animations")
return
animations = list(map(prepare_animation, proto_animations))
for anim in animations:
anim.update_rate_info(run_time, rate_func, lag_ratio)
self.pre_play()
self.begin_animations(animations)
self.progress_through_animations(animations)
self.finish_animations(animations)
self.post_play()
def wait(
self,
duration: Optional[float] = None,
stop_condition: Callable[[], bool] = None,
note: str = None,
ignore_presenter_mode: bool = False
):
if duration is None:
duration = self.default_wait_time
self.pre_play()
self.update_mobjects(dt=0) # Any problems with this?
if self.presenter_mode and not self.skip_animations and not ignore_presenter_mode:
if note:
log.info(note)
self.hold_loop()
else:
time_progression = self.get_wait_time_progression(duration, stop_condition)
last_t = 0
for t in time_progression:
dt = t - last_t
last_t = t
self.update_frame(dt)
self.emit_frame()
if stop_condition is not None and stop_condition():
break
self.post_play()
def hold_loop(self):
while self.hold_on_wait:
self.update_frame(dt=1 / self.camera.fps)
self.hold_on_wait = True
def wait_until(
self,
stop_condition: Callable[[], bool],
max_time: float = 60
):
self.wait(max_time, stop_condition=stop_condition)
def force_skipping(self):
self.original_skipping_status = self.skip_animations
self.skip_animations = True
return self
def revert_to_original_skipping_status(self):
if hasattr(self, "original_skipping_status"):
self.skip_animations = self.original_skipping_status
return self
def add_sound(
self,
sound_file: str,
time_offset: float = 0,
gain: float | None = None,
gain_to_background: float | None = None
):
if self.skip_animations:
return
time = self.get_time() + time_offset
self.file_writer.add_sound(sound_file, time, gain, gain_to_background)
# Helpers for interactive development
def get_state(self) -> SceneState:
return SceneState(self)
@affects_mobject_list
def restore_state(self, scene_state: SceneState):
scene_state.restore_scene(self)
def save_state(self) -> None:
state = self.get_state()
if self.undo_stack and state.mobjects_match(self.undo_stack[-1]):
return
self.redo_stack = []
self.undo_stack.append(state)
if len(self.undo_stack) > self.max_num_saved_states:
self.undo_stack.pop(0)
def undo(self):
if self.undo_stack:
self.redo_stack.append(self.get_state())
self.restore_state(self.undo_stack.pop())
def redo(self):
if self.redo_stack:
self.undo_stack.append(self.get_state())
self.restore_state(self.redo_stack.pop())
@contextmanager
def temp_skip(self):
prev_status = self.skip_animations
self.skip_animations = True
try:
yield
finally:
if not prev_status:
self.stop_skipping()
@contextmanager
def temp_progress_bar(self):
prev_progress = self.show_animation_progress
self.show_animation_progress = True
try:
yield
finally:
self.show_animation_progress = prev_progress
@contextmanager
def temp_record(self):
self.camera.use_window_fbo(False)
self.file_writer.begin_insert()
try:
yield
finally:
self.file_writer.end_insert()
self.camera.use_window_fbo(True)
def temp_config_change(self, skip=False, record=False, progress_bar=False):
stack = ExitStack()
if skip:
stack.enter_context(self.temp_skip())
if record:
stack.enter_context(self.temp_record())
if progress_bar:
stack.enter_context(self.temp_progress_bar())
return stack
def is_window_closing(self):
return self.window and (self.window.is_closing or self.quit_interaction)
# Event handling
def set_floor_plane(self, plane: str = "xy"):
if plane == "xy":
self.frame.set_euler_axes("zxz")
elif plane == "xz":
self.frame.set_euler_axes("zxy")
else:
raise Exception("Only `xz` and `xy` are valid floor planes")
def on_mouse_motion(
self,
point: Vect3,
d_point: Vect3
) -> None:
assert self.window is not None
self.mouse_point.move_to(point)
event_data = {"point": point, "d_point": d_point}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.MouseMotionEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
frame = self.camera.frame
# Handle perspective changes
if self.window.is_key_pressed(ord(manim_config.key_bindings.pan_3d)):
ff_d_point = frame.to_fixed_frame_point(d_point, relative=True)
ff_d_point *= self.pan_sensitivity
frame.increment_theta(-ff_d_point[0])
frame.increment_phi(ff_d_point[1])
# Handle frame movements
elif self.window.is_key_pressed(ord(manim_config.key_bindings.pan)):
frame.shift(-d_point)
def on_mouse_drag(
self,
point: Vect3,
d_point: Vect3,
buttons: int,
modifiers: int
) -> None:
self.mouse_drag_point.move_to(point)
if self.drag_to_pan:
self.frame.shift(-d_point)
event_data = {"point": point, "d_point": d_point, "buttons": buttons, "modifiers": modifiers}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.MouseDragEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
def on_mouse_press(
self,
point: Vect3,
button: int,
mods: int
) -> None:
self.mouse_drag_point.move_to(point)
event_data = {"point": point, "button": button, "mods": mods}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.MousePressEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
def on_mouse_release(
self,
point: Vect3,
button: int,
mods: int
) -> None:
event_data = {"point": point, "button": button, "mods": mods}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.MouseReleaseEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
def on_mouse_scroll(
self,
point: Vect3,
offset: Vect3,
x_pixel_offset: float,
y_pixel_offset: float
) -> None:
event_data = {"point": point, "offset": offset}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.MouseScrollEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
rel_offset = y_pixel_offset / self.camera.get_pixel_height()
self.frame.scale(
1 - self.scroll_sensitivity * rel_offset,
about_point=point
)
def on_key_release(
self,
symbol: int,
modifiers: int
) -> None:
event_data = {"symbol": symbol, "modifiers": modifiers}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.KeyReleaseEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
def on_key_press(
self,
symbol: int,
modifiers: int
) -> None:
try:
char = chr(symbol)
except OverflowError:
log.warning("The value of the pressed key is too large.")
return
event_data = {"symbol": symbol, "modifiers": modifiers}
propagate_event = EVENT_DISPATCHER.dispatch(EventType.KeyPressEvent, **event_data)
if propagate_event is not None and propagate_event is False:
return
if char == manim_config.key_bindings.reset:
self.play(self.camera.frame.animate.to_default_state())
elif char == "z" and (modifiers & (PygletWindowKeys.MOD_COMMAND | PygletWindowKeys.MOD_CTRL)):
self.undo()
elif char == "z" and (modifiers & (PygletWindowKeys.MOD_COMMAND | PygletWindowKeys.MOD_CTRL | PygletWindowKeys.MOD_SHIFT)):
self.redo()
# command + q
elif char == manim_config.key_bindings.quit and (modifiers & (PygletWindowKeys.MOD_COMMAND | PygletWindowKeys.MOD_CTRL)):
self.quit_interaction = True
# Space or right arrow
elif char == " " or symbol == PygletWindowKeys.RIGHT:
self.hold_on_wait = False
def on_resize(self, width: int, height: int) -> None:
pass
def on_show(self) -> None:
pass
def on_hide(self) -> None:
pass
def on_close(self) -> None:
pass
def focus(self) -> None:
"""
Puts focus on the ManimGL window.
"""
if not self.window:
return
self.window.focus()
class SceneState():
def __init__(self, scene: Scene, ignore: list[Mobject] | None = None):
self.time = scene.time
self.num_plays = scene.num_plays
self.mobjects_to_copies = OrderedDict.fromkeys(scene.mobjects)
if ignore:
for mob in ignore:
self.mobjects_to_copies.pop(mob, None)
last_m2c = scene.undo_stack[-1].mobjects_to_copies if scene.undo_stack else dict()
for mob in self.mobjects_to_copies:
# If it hasn't changed since the last state, just point to the
# same copy as before
if mob in last_m2c and last_m2c[mob].looks_identical(mob):
self.mobjects_to_copies[mob] = last_m2c[mob]
else:
self.mobjects_to_copies[mob] = mob.copy()
def __eq__(self, state: SceneState):
return all((
self.time == state.time,
self.num_plays == state.num_plays,
self.mobjects_to_copies == state.mobjects_to_copies
))
def mobjects_match(self, state: SceneState):
return self.mobjects_to_copies == state.mobjects_to_copies
def n_changes(self, state: SceneState):
m2c = state.mobjects_to_copies
return sum(
1 - int(mob in m2c and mob.looks_identical(m2c[mob]))
for mob in self.mobjects_to_copies
)
def restore_scene(self, scene: Scene):
scene.time = self.time
scene.num_plays = self.num_plays
scene.mobjects = [
mob.become(mob_copy)
for mob, mob_copy in self.mobjects_to_copies.items()
]
class EndScene(Exception):
pass
class ThreeDScene(Scene):
samples = 4
default_frame_orientation = (-30, 70)
always_depth_test = True
def add(self, *mobjects: Mobject, set_depth_test: bool = True, perp_stroke: bool = True):
for mob in mobjects:
if set_depth_test and not mob.is_fixed_in_frame() and self.always_depth_test:
mob.apply_depth_test()
if isinstance(mob, VMobject) and mob.has_stroke() and perp_stroke:
mob.set_flat_stroke(False)
super().add(*mobjects)