Renderer refactor (#532)

Factors Scene.camera, Scene.file_writer, and rendering logic within Scene into a new CairoRenderer class

Author: eulertour

docs/source/examples/3d.rst

@@ -32,7 +32,7 @@
                 ]), v_min=0, v_max=TAU, u_min=-PI / 2, u_max=PI / 2,
                 checkerboard_colors=[RED_D, RED_E], resolution=(15, 32)
             )
-            self.camera.light_source.move_to(3*IN) # changes the source of the light
+            self.renderer.camera.light_source.move_to(3*IN) # changes the source of the light
             self.set_camera_orientation(phi=75 * DEGREES, theta=30 * DEGREES)
             self.add(axes, sphere)
 

manim/__init__.py

@@ -21,6 +21,8 @@
 from .animation.transform import *
 from .animation.update import *
 
+from .renderer.cairo_renderer import *
+
 from .camera.camera import *
 from .camera.mapping_camera import *
 from .camera.moving_camera import *

manim/__main__.py

@@ -1,22 +1,16 @@
-import inspect
 import os
 import platform
-import subprocess as sp
 import sys
-import re
 import traceback
-import importlib.util
-import types
 
-from . import constants, logger, console, file_writer_config
+from . import logger, file_writer_config
 from .config.config import camera_config, args
 from .config import cfg_subcmds
 from .utils.module_ops import (
     get_module,
     get_scene_classes_from_module,
     get_scenes_to_render,
 )
-from .scene.scene import Scene
 from .utils.file_ops import open_file as open_media_file
 from .grpc.impl import frame_server_impl
 
@@ -79,7 +73,7 @@ def main():
                 else:
                     scene = SceneClass()
                     scene.render()
-                    open_file_if_needed(scene.file_writer)
+                    open_file_if_needed(scene.renderer.file_writer)
             except Exception:
                 print("\n\n")
                 traceback.print_exc()

manim/camera/camera.py

@@ -28,6 +28,7 @@
 from ..utils.simple_functions import fdiv
 from ..utils.space_ops import angle_of_vector
 from ..utils.space_ops import get_norm
+from ..utils.family import extract_mobject_family_members
 
 
 class Camera(object):
@@ -66,7 +67,7 @@ class Camera(object):
         "use_z_index": True,
     }
 
-    def __init__(self, background=None, **kwargs):
+    def __init__(self, video_quality_config, background=None, **kwargs):
         """Initialises the Camera.
 
         Parameters
@@ -363,33 +364,6 @@ def set_frame_to_background(self, background):
 
     ####
 
-    # TODO, it's weird that this is part of camera.
-    # Clearly it should live elsewhere.
-    def extract_mobject_family_members(self, mobjects, only_those_with_points=False):
-        """Returns a list of the types of mobjects and
-        their family members present.
-
-        Parameters
-        ----------
-        mobjects : Mobject
-            The Mobjects currently in the Scene
-        only_those_with_points : bool, optional
-            Whether or not to only do this for
-            those mobjects that have points. By default False
-
-        Returns
-        -------
-        list
-            list of the mobjects and family members.
-        """
-        if only_those_with_points:
-            method = Mobject.family_members_with_points
-        else:
-            method = Mobject.get_family
-        if self.use_z_index:
-            mobjects = sorted(mobjects, key=lambda m: m.z_index)
-        return remove_list_redundancies(list(it.chain(*[method(m) for m in mobjects])))
-
     def get_mobjects_to_display(
         self, mobjects, include_submobjects=True, excluded_mobjects=None
     ):
@@ -411,11 +385,13 @@ def get_mobjects_to_display(
             list of mobjects
         """
         if include_submobjects:
-            mobjects = self.extract_mobject_family_members(
-                mobjects, only_those_with_points=True
+            mobjects = extract_mobject_family_members(
+                mobjects, use_z_index=self.use_z_index, only_those_with_points=True
             )
             if excluded_mobjects:
-                all_excluded = self.extract_mobject_family_members(excluded_mobjects)
+                all_excluded = extract_mobject_family_members(
+                    excluded_mobjects, use_z_index=self.use_z_index
+                )
                 mobjects = list_difference_update(mobjects, all_excluded)
         return mobjects
 

manim/camera/moving_camera.py

@@ -46,7 +46,7 @@ class MovingCamera(Camera):
         "default_frame_stroke_width": 0,
     }
 
-    def __init__(self, frame=None, **kwargs):
+    def __init__(self, video_quality_config, frame=None, **kwargs):
         """
         frame is a Mobject, (should almost certainly be a rectangle)
         determining which region of space the camera displys
@@ -59,7 +59,7 @@ def __init__(self, frame=None, **kwargs):
                 self.default_frame_stroke_width,
             )
         self.frame = frame
-        Camera.__init__(self, **kwargs)
+        Camera.__init__(self, video_quality_config, **kwargs)
 
     # TODO, make these work for a rotated frame
     @property

manim/camera/multi_camera.py

@@ -14,7 +14,9 @@ class MultiCamera(MovingCamera):
         "allow_cameras_to_capture_their_own_display": False,
     }
 
-    def __init__(self, *image_mobjects_from_cameras, **kwargs):
+    def __init__(
+        self, video_quality_config, image_mobjects_from_cameras=None, **kwargs
+    ):
         """Initalises the MultiCamera
 
         Parameters:
@@ -25,9 +27,10 @@ def __init__(self, *image_mobjects_from_cameras, **kwargs):
             Any valid keyword arguments of MovingCamera.
         """
         self.image_mobjects_from_cameras = []
-        for imfc in image_mobjects_from_cameras:
-            self.add_image_mobject_from_camera(imfc)
-        MovingCamera.__init__(self, **kwargs)
+        if image_mobjects_from_cameras is not None:
+            for imfc in image_mobjects_from_cameras:
+                self.add_image_mobject_from_camera(imfc)
+        MovingCamera.__init__(self, video_quality_config, **kwargs)
 
     def add_image_mobject_from_camera(self, image_mobject_from_camera):
         """Adds an ImageMobject that's been obtained from the camera

manim/grpc/impl/frame_server_impl.py

@@ -98,7 +98,7 @@ def GetFrameAtTime(self, request, context):
                 selected_scene.static_image,
             )
             serialized_mobject_list, duration = selected_scene.add_frame(
-                selected_scene.get_frame()
+                selected_scene.renderer.get_frame()
             )
             resp = list_to_frame_response(
                 selected_scene, duration, serialized_mobject_list

manim/renderer/__init__.py

@@ -0,0 +1,215 @@
+import numpy as np
+from .. import config, camera_config, file_writer_config
+from ..utils.iterables import list_update
+from ..utils.exceptions import EndSceneEarlyException
+from ..constants import DEFAULT_WAIT_TIME
+from ..scene.scene_file_writer import SceneFileWriter
+from ..utils.caching import handle_caching_play, handle_caching_wait
+from ..camera.camera import Camera
+
+
+def pass_scene_reference(func):
+    def wrapper(self, scene, *args, **kwargs):
+        func(self, scene, *args, **kwargs)
+
+    return wrapper
+
+
+def handle_play_like_call(func):
+    """
+    This method is used internally to wrap the
+    passed function, into a function that
+    actually writes to the video stream.
+    Simultaneously, it also adds to the number
+    of animations played.
+
+    Parameters
+    ----------
+    func : function
+        The play() like function that has to be
+        written to the video file stream.
+
+    Returns
+    -------
+    function
+        The play() like function that can now write
+        to the video file stream.
+    """
+
+    def wrapper(self, scene, *args, **kwargs):
+        allow_write = not file_writer_config["skip_animations"]
+        self.file_writer.begin_animation(allow_write)
+        func(self, scene, *args, **kwargs)
+        self.file_writer.end_animation(allow_write)
+        self.num_plays += 1
+
+    return wrapper
+
+
+class CairoRenderer:
+    """A renderer using Cairo.
+
+    num_plays : Number of play() functions in the scene.
+    time: time elapsed since initialisation of scene.
+    """
+
+    def __init__(self, camera_class=None, **kwargs):
+        # All of the following are set to EITHER the value passed via kwargs,
+        # OR the value stored in the global config dict at the time of
+        # _instance construction_.  Before, they were in the CONFIG dict, which
+        # is a class attribute and is defined at the time of _class
+        # definition_.  This did not allow for creating two Cameras with
+        # different configurations in the same session.
+        self.file_writer = None
+        self.video_quality_config = {}
+        for attr in [
+            "pixel_height",
+            "pixel_width",
+            "frame_height",
+            "frame_width",
+            "frame_rate",
+        ]:
+            self.video_quality_config[attr] = kwargs.get(attr, config[attr])
+        camera_cls = camera_class if camera_class is not None else Camera
+        self.camera = camera_cls(self.video_quality_config, **camera_config)
+        self.original_skipping_status = file_writer_config["skip_animations"]
+        self.animations_hashes = []
+        self.num_plays = 0
+        self.time = 0
+
+    def init(self, scene):
+        self.file_writer = SceneFileWriter(
+            self,
+            self.video_quality_config,
+            scene.__class__.__name__,
+            **file_writer_config,
+        )
+
+    @pass_scene_reference
+    @handle_caching_play
+    @handle_play_like_call
+    def play(self, scene, *args, **kwargs):
+        scene.play_internal(*args, **kwargs)
+
+    @pass_scene_reference
+    @handle_caching_wait
+    @handle_play_like_call
+    def wait(self, scene, duration=DEFAULT_WAIT_TIME, stop_condition=None):
+        scene.wait_internal(duration=duration, stop_condition=stop_condition)
+
+    def update_frame(  # TODO Description in Docstring
+        self,
+        scene,
+        mobjects=None,
+        background=None,
+        include_submobjects=True,
+        ignore_skipping=True,
+        **kwargs,
+    ):
+        """Update the frame.
+
+        Parameters
+        ----------
+        mobjects: list, optional
+            list of mobjects
+
+        background: np.ndarray, optional
+            Pixel Array for Background.
+
+        include_submobjects: bool, optional
+
+        ignore_skipping : bool, optional
+
+        **kwargs
+
+        """
+        if file_writer_config["skip_animations"] and not ignore_skipping:
+            return
+        if mobjects is None:
+            mobjects = list_update(
+                scene.mobjects,
+                scene.foreground_mobjects,
+            )
+        if background is not None:
+            self.camera.set_frame_to_background(background)
+        else:
+            self.camera.reset()
+
+        kwargs["include_submobjects"] = include_submobjects
+        self.camera.capture_mobjects(mobjects, **kwargs)
+
+    def get_frame(self):
+        """
+        Gets the current frame as NumPy array.
+
+        Returns
+        -------
+        np.array
+            NumPy array of pixel values of each pixel in screen.
+            The shape of the array is height x width x 3
+        """
+        return np.array(self.camera.pixel_array)
+
+    def add_frame(self, frame, num_frames=1):
+        """
+        Adds a frame to the video_file_stream
+
+        Parameters
+        ----------
+        frame : numpy.ndarray
+            The frame to add, as a pixel array.
+        num_frames: int
+            The number of times to add frame.
+        """
+        dt = 1 / self.camera.frame_rate
+        self.time += num_frames * dt
+        if file_writer_config["skip_animations"]:
+            return
+        for _ in range(num_frames):
+            self.file_writer.write_frame(frame)
+
+    def show_frame(self):
+        """
+        Opens the current frame in the Default Image Viewer
+        of your system.
+        """
+        self.update_frame(ignore_skipping=True)
+        self.camera.get_image().show()
+
+    def update_skipping_status(self):
+        """
+        This method is used internally to check if the current
+        animation needs to be skipped or not. It also checks if
+        the number of animations that were played correspond to
+        the number of animations that need to be played, and
+        raises an EndSceneEarlyException if they don't correspond.
+        """
+        if file_writer_config["from_animation_number"]:
+            if self.num_plays < file_writer_config["from_animation_number"]:
+                file_writer_config["skip_animations"] = True
+        if file_writer_config["upto_animation_number"]:
+            if self.num_plays > file_writer_config["upto_animation_number"]:
+                file_writer_config["skip_animations"] = True
+                raise EndSceneEarlyException()
+
+    def revert_to_original_skipping_status(self):
+        """
+        Forces the scene to go back to its original skipping status,
+        by setting skip_animations to whatever it reads
+        from original_skipping_status.
+
+        Returns
+        -------
+        Scene
+            The Scene, with the original skipping status.
+        """
+        if hasattr(self, "original_skipping_status"):
+            file_writer_config["skip_animations"] = self.original_skipping_status
+        return self
+
+    def finish(self, scene):
+        file_writer_config["skip_animations"] = False
+        self.file_writer.finish()
+        if file_writer_config["save_last_frame"]:
+            self.update_frame(scene, ignore_skipping=True)
+            self.file_writer.save_final_image(self.camera.get_image())

manim/renderer/cairo_renderer.py

@@ -109,7 +109,6 @@ def progress_through_animations(self):
                     logger.error(e)
             self.animation_finished.wait()
 
-    @scene.handle_play_like_call
     def wait(self, duration=DEFAULT_WAIT_TIME, stop_condition=None):
         self.update_mobjects(dt=0)  # Any problems with this?
         self.animations = []