release: ready to release v1.3.0

Construct `MTex`

docs/source/development/changelog.rst

@@ -1,6 +1,70 @@
 Changelog
 =========
 
+v1.3.0
+------
+
+Fixed bugs 
+^^^^^^^^^^
+
+- `#1653 <https://github.com/3b1b/manim/pull/1653>`__: Fixed ``Mobject.stretch_to_fit_depth``
+- `#1655 <https://github.com/3b1b/manim/pull/1655>`__: Fixed the bug of rotating camera
+- `c73d507 <https://github.com/3b1b/manim/pull/1688/commits/c73d507c76af5c8602d4118bc7538ba04c03ebae>`__: Fixed ``SurfaceMesh`` to be evenly spaced
+- `82bd02d <https://github.com/3b1b/manim/pull/1688/commits/82bd02d21fbd89b71baa21e077e143f440df9014>`__: Fixed ``angle_between_vectors`` add ``rotation_between_vectors``
+- `a717314 <https://github.com/3b1b/manim/pull/1688/commits/a7173142bf93fd309def0cc10f3c56f5e6972332>`__: Fixed ``VMobject.fade``
+- `fbc329d <https://github.com/3b1b/manim/pull/1688/commits/fbc329d7ce3b11821d47adf6052d932f7eff724a>`__: Fixed ``angle_between_vectors``
+- `bcd0990 <https://github.com/3b1b/manim/pull/1688/commits/bcd09906bea5eaaa5352e7bee8f3153f434cf606>`__: Fixed bug in ``ShowSubmobjectsOneByOne``
+- `7023548 <https://github.com/3b1b/manim/pull/1691/commits/7023548ec62c4adb2f371aab6a8c7f62deb7c33c>`__: Fixed bug in ``TransformMatchingParts``
+
+New Features
+^^^^^^^^^^^^
+
+- `e10f850 <https://github.com/3b1b/manim/commit/e10f850d0d9f971931cc85d44befe67dc842af6d>`__: Added CLI flag ``--log-level`` to specify log level
+- `#1667 <https://github.com/3b1b/manim/pull/1667>`__: Added operations (``+`` and ``*``) for ``Mobject``
+- `#1675 <https://github.com/3b1b/manim/pull/1675>`__: Added 4 boolean operations for ``VMobject`` in ``manimlib/mobject/boolean_ops.py``
+
+  - ``Union(*vmobjects, **kwargs)``  
+  - ``Difference(subject, clip, **kwargs)`` 
+  - ``Intersection(*vmobjects, **kwargs)`` 
+  - ``Exclusion(*vmobjects, **kwargs)`` 
+- `81c3ae3 <https://github.com/3b1b/manim/pull/1688/commits/81c3ae30372e288dc772633dbd17def6e603753e>`__: Added reflectiveness
+- `2c7689e <https://github.com/3b1b/manim/pull/1688/commits/2c7689ed9e81229ce87c648f97f26267956c0bc9>`__: Enabled ``glow_factor`` on ``DotCloud``
+- `d065e19 <https://github.com/3b1b/manim/pull/1688/commits/d065e1973d1d6ebd2bece81ce4bdf0c2fff7c772>`__: Added option ``-e`` to insert embed line from the command line
+- `0e78027 <https://github.com/3b1b/manim/pull/1688/commits/0e78027186a976f7e5fa8d586f586bf6e6baab8d>`__: Improved ``point_from_proportion`` to account for arc length
+- `781a993 <https://github.com/3b1b/manim/pull/1688/commits/781a9934fda6ba11f22ba32e8ccddcb3ba78592e>`__: Added shortcut ``set_backstroke`` for setting black background stroke
+- `0b898a5 <https://github.com/3b1b/manim/pull/1688/commits/0b898a5594203668ed9cad38b490ab49ba233bd4>`__: Added ``Suface.always_sort_to_camera``
+- `e899604 <https://github.com/3b1b/manim/pull/1688/commits/e899604a2d05f78202fcb3b9824ec34647237eae>`__: Added getter methods for specific euler angles
+- `407c53f <https://github.com/3b1b/manim/pull/1688/commits/407c53f97c061bfd8a53beacd88af4c786f9e9ee>`__: Hade ``rotation_between_vectors`` handle identical/similar vectors
+- `49743da <https://github.com/3b1b/manim/pull/1688/commits/49743daf3244bfa11a427040bdde8e2bb79589e8>`__: Added ``Mobject.insert_submobject`` method
+- `9dd1f47 <https://github.com/3b1b/manim/pull/1688/commits/9dd1f47dabca1580d6102e34e44574b0cba556e7>`__: Created single progress display for full scene render
+- `264f7b1 <https://github.com/3b1b/manim/pull/1691/commits/264f7b11726e9e736f0fe472f66e38539f74e848>`__: Added ``Circle.get_radius``
+- `83841ae <https://github.com/3b1b/manim/pull/1691/commits/83841ae41568a9c9dff44cd163106c19a74ac281>`__: Added ``Dodecahedron``
+- `a1d5147 <https://github.com/3b1b/manim/pull/1691/commits/a1d51474ea1ce3b7aa3efbe4c5e221be70ee2f5b>`__: Added ``GlowDot``
+- `#1678 <https://github.com/3b1b/manim/pull/1678>`__: Added ``MTex`` , see `#1678 <https://github.com/3b1b/manim/pull/1678>`__ for details
+
+Refactor
+^^^^^^^^
+
+- `#1662 <https://github.com/3b1b/manim/pull/1662>`__: Refactored support for command ``A`` in path of SVG 
+- `#1662 <https://github.com/3b1b/manim/pull/1662>`__: Refactored ``SingleStringTex.balance_braces``
+- `8b454fb <https://github.com/3b1b/manim/pull/1688/commits/8b454fbe9335a7011e947093230b07a74ba9c653>`__: Slight tweaks to how saturation_factor works on newton-fractal
+- `317a5d6 <https://github.com/3b1b/manim/pull/1688/commits/317a5d6226475b6b54a78db7116c373ef84ea923>`__: Made it possible to set full screen preview as a default
+- `e764da3 <https://github.com/3b1b/manim/pull/1688/commits/e764da3c3adc5ae2a4ce877b340d2b6abcddc2fc>`__: Used ``quick_point_from_proportion`` for graph points
+- `d2182b9 <https://github.com/3b1b/manim/pull/1688/commits/d2182b9112300558b6c074cefd685f97c10b3898>`__: Made sure ``Line.set_length`` returns self
+- `eea3c6b <https://github.com/3b1b/manim/pull/1688/commits/eea3c6b29438f9e9325329c4355e76b9f635e97a>`__: Better align ``SurfaceMesh`` to the corresponding surface polygons
+- `ee1594a <https://github.com/3b1b/manim/pull/1688/commits/ee1594a3cb7a79b8fc361e4c4397a88c7d20c7e3>`__: Match ``fix_in_frame`` status for ``FlashAround`` mobject
+- `ba23fbe <https://github.com/3b1b/manim/pull/1688/commits/ba23fbe71e4a038201cd7df1d200514ed1c13bc2>`__: Made sure ``Mobject.is_fixed_in_frame`` stays updated with uniforms
+- `98b0d26 <https://github.com/3b1b/manim/pull/1691/commits/98b0d266d2475926a606331923cca3dc1dea97ad>`__: Made sure ``skip_animations`` and ``start_at_animation_number`` play well together
+- `f8e6e7d <https://github.com/3b1b/manim/pull/1691/commits/f8e6e7df3ceb6f3d845ced4b690a85b35e0b8d00>`__: Updated progress display for full scene render
+- `8f1dfab <https://github.com/3b1b/manim/pull/1691/commits/8f1dfabff04a8456f5c4df75b0f97d50b2755003>`__: ``VectorizedPoint`` should call ``__init__`` for both super classes
+- `758f329 <https://github.com/3b1b/manim/pull/1691/commits/758f329a06a0c198b27a48c577575d94554305bf>`__: Used array copy when checking need for refreshing triangulation
+
+
+Dependencies
+^^^^^^^^^^^^
+
+- `#1675 <https://github.com/3b1b/manim/pull/1675>`__: Added dependency on python packages `skia-pathops <https://github.com/fonttools/skia-pathops>`__
+
 v1.2.0
 ------
 

docs/source/getting_started/config.rst

@@ -83,22 +83,3 @@ Its value is a dictionary, passed in as ``kwargs`` when initializing the ``Camer
 to modify the value of the properties of the ``Camera`` class.
 
 So the nesting of the ``CONFIG`` dictionary **essentially** passes in the value as ``kwargs``.
-
-Common usage
-------------
-
-When writing a class by yourself, you can add attributes or modify the attributes 
-of the parent class through ``CONFIG``.
-
-The most commonly used is to modify the properties of the camera when writing a ``Scene``:
-
-.. code-block:: python
-
-    class YourScene(Scene):
-        CONFIG = {
-            "camera_config": {
-                "background_color": WHITE,
-            },
-        }
-
-For example, the above dictionary will change the background color to white, etc.

docs/source/getting_started/configuration.rst

@@ -53,6 +53,7 @@ flag                                                       abbr   function
 ``--config``                                                      Guide for automatic configuration
 ``--file_name FILE_NAME``                                         Name for the movie or image file
 ``--start_at_animation_number START_AT_ANIMATION_NUMBER``  ``-n`` Start rendering not from the first animation, but from another, specified by its index. If you passing two comma separated values, e.g. "3,6", it will end the rendering at the second value.
+``--embed LINENO``                                         ``-e`` Takes a line number as an argument, and results in the scene being called as if the line ``self.embed()`` was inserted into the scene code at that line number
 ``--resolution RESOLUTION``                                ``-r`` Resolution, passed as "WxH", e.g. "1920x1080"
 ``--frame_rate FRAME_RATE``                                       Frame rate, as an integer
 ``--color COLOR``                                          ``-c`` Background color

docs/source/index.rst

@@ -6,7 +6,7 @@ Manim's documentation
 Manim is an animation engine for explanatory math videos. It's used to create precise animations programmatically, as seen in the videos
 at `3Blue1Brown <https://www.3blue1brown.com/>`_.
 
-And here is a Chinese version of this documentation: https://docs.manim.org.cn/shaders
+And here is a Chinese version of this documentation: https://docs.manim.org.cn/
 
 .. toctree::
    :maxdepth: 2

manimlib/__init__.py

@@ -22,6 +22,7 @@ from manimlib.camera.camera import *
 
 from manimlib.window import *
 
+from manimlib.mobject.boolean_ops import *
 from manimlib.mobject.coordinate_systems import *
 from manimlib.mobject.changing import *
 from manimlib.mobject.frame import *
@@ -36,6 +37,7 @@ from manimlib.mobject.probability import *
 from manimlib.mobject.shape_matchers import *
 from manimlib.mobject.svg.brace import *
 from manimlib.mobject.svg.drawings import *
+from manimlib.mobject.svg.mtex_mobject import *
 from manimlib.mobject.svg.svg_mobject import *
 from manimlib.mobject.svg.tex_mobject import *
 from manimlib.mobject.svg.text_mobject import *

manimlib/__main__.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 import manimlib.config
+import manimlib.logger
 import manimlib.extract_scene
 import manimlib.utils.init_config
 from manimlib import __version__
@@ -9,8 +10,10 @@ def main():
     print(f"ManimGL \033[32mv{__version__}\033[0m")
 
     args = manimlib.config.parse_cli()
-    if args.version and args.file == None:
+    if args.version and args.file is None:
         return
+    if args.log_level:
+        manimlib.logger.log.setLevel(args.log_level)
 
     if args.config:
         manimlib.utils.init_config.init_customization()
@@ -21,5 +24,6 @@ def main():
         for scene in scenes:
             scene.run()
 
+
 if __name__ == "__main__":
     main()

manimlib/animation/creation.py

@@ -174,16 +174,12 @@ class ShowSubmobjectsOneByOne(ShowIncreasingSubsets):
         "int_func": np.ceil,
     }
 
-    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.set_submobjects([])
         else:
-            self.mobject.set_submobjects(self.all_submobs[index - 1])
+            self.mobject.set_submobjects([self.all_submobs[index - 1]])
 
 
 # TODO, this is broken...

manimlib/animation/indication.py

@@ -224,6 +224,8 @@ class FlashAround(VShowPassingFlash):
     def __init__(self, mobject, **kwargs):
         digest_config(self, kwargs)
         path = self.get_path(mobject)
+        if mobject.is_fixed_in_frame:
+            path.fix_in_frame()
         path.insert_n_curves(self.n_inserted_curves)
         path.set_points(path.get_points_without_null_curves())
         path.set_stroke(self.color, self.stroke_width)

manimlib/animation/transform_matching_parts.py

@@ -68,10 +68,10 @@ class TransformMatchingParts(AnimationGroup):
             anims.append(FadeTransformPieces(fade_source, fade_target, **kwargs))
         else:
             anims.append(FadeOutToPoint(
-                fade_source, fade_target.get_center(), **kwargs
+                fade_source, target_mobject.get_center(), **kwargs
             ))
             anims.append(FadeInFromPoint(
-                fade_target.copy(), fade_source.get_center(), **kwargs
+                fade_target.copy(), mobject.get_center(), **kwargs
             ))
 
         super().__init__(*anims)

manimlib/camera/camera.py

@@ -1,4 +1,5 @@
 import moderngl
+import math
 from colour import Color
 import OpenGL.GL as gl
 
@@ -67,7 +68,7 @@ class CameraFrame(Mobject):
         added_rot_T = rotation_matrix_transpose(angle, axis)
         new_rot_T = np.dot(curr_rot_T, added_rot_T)
         Fz = new_rot_T[2]
-        phi = np.arccos(Fz[2])
+        phi = np.arccos(clip(Fz[2], -1, 1))
         theta = angle_of_vector(Fz[:2]) + PI / 2
         partial_rot_T = np.dot(
             rotation_matrix_transpose(phi, RIGHT),
@@ -121,6 +122,15 @@ class CameraFrame(Mobject):
         self.refresh_rotation_matrix()
         return self
 
+    def get_theta(self):
+        return self.data["euler_angles"][0]
+
+    def get_phi(self):
+        return self.data["euler_angles"][1]
+
+    def get_gamma(self):
+        return self.data["euler_angles"][2]
+
     def get_shape(self):
         return (self.get_width(), self.get_height())
 
@@ -139,6 +149,16 @@ class CameraFrame(Mobject):
     def get_focal_distance(self):
         return self.focal_distance * self.get_height()
 
+    def get_implied_camera_location(self):
+        theta, phi, gamma = self.get_euler_angles()
+        dist = self.get_focal_distance()
+        x, y, z = self.get_center()
+        return (
+            x + dist * math.sin(theta) * math.sin(phi),
+            y - dist * math.cos(theta) * math.sin(phi),
+            z + dist * math.cos(phi)
+        )
+
     def interpolate(self, *args, **kwargs):
         super().interpolate(*args, **kwargs)
         self.refresh_rotation_matrix()
@@ -194,20 +214,30 @@ class Camera(object):
             fbo = self.get_fbo(ctx, 0)
         else:
             fbo = ctx.detect_framebuffer()
+        self.ctx = ctx
+        self.fbo = fbo
+        self.set_ctx_blending()
 
         # For multisample antialiasing
         fbo_msaa = self.get_fbo(ctx, self.samples)
         fbo_msaa.use()
+        self.fbo_msaa = fbo_msaa
 
-        ctx.enable(moderngl.BLEND)
-        ctx.blend_func = (
+    def set_ctx_blending(self, enable=True):
+        if enable:
+            self.ctx.enable(moderngl.BLEND)
+        else:
+            self.ctx.disable(moderngl.BLEND)
+        self.ctx.blend_func = (
             moderngl.SRC_ALPHA, moderngl.ONE_MINUS_SRC_ALPHA,
-            moderngl.ONE, moderngl.ONE
+            # moderngl.ONE, moderngl.ONE
         )
 
-        self.ctx = ctx
-        self.fbo = fbo
-        self.fbo_msaa = fbo_msaa
+    def set_ctx_depth_test(self, enable=True):
+        if enable:
+            self.ctx.enable(moderngl.DEPTH_TEST)
+        else:
+            self.ctx.disable(moderngl.DEPTH_TEST)
 
     def init_light_source(self):
         self.light_source = Point(self.light_source_position)
@@ -297,6 +327,9 @@ class Camera(object):
     def get_frame_center(self):
         return self.frame.get_center()
 
+    def get_location(self):
+        return self.frame.get_implied_camera_location()
+
     def resize_frame_shape(self, fixed_dimension=0):
         """
         Changes frame_shape to match the aspect ratio
@@ -327,17 +360,11 @@ class Camera(object):
         shader_wrapper = render_group["shader_wrapper"]
         shader_program = render_group["prog"]
         self.set_shader_uniforms(shader_program, shader_wrapper)
-        self.update_depth_test(shader_wrapper)
+        self.set_ctx_depth_test(shader_wrapper.depth_test)
         render_group["vao"].render(int(shader_wrapper.render_primitive))
         if render_group["single_use"]:
             self.release_render_group(render_group)
 
-    def update_depth_test(self, shader_wrapper):
-        if shader_wrapper.depth_test:
-            self.ctx.enable(moderngl.DEPTH_TEST)
-        else:
-            self.ctx.disable(moderngl.DEPTH_TEST)
-
     def get_render_group_list(self, mobject):
         try:
             return self.static_mobject_to_render_group_list[id(mobject)]
@@ -410,7 +437,7 @@ class Camera(object):
         for name, path in shader_wrapper.texture_paths.items():
             tid = self.get_texture_id(path)
             shader[name].value = tid
-        for name, value in it.chain(shader_wrapper.uniforms.items(), self.perspective_uniforms.items()):
+        for name, value in it.chain(self.perspective_uniforms.items(), shader_wrapper.uniforms.items()):
             try:
                 if isinstance(value, np.ndarray):
                     value = tuple(value)
@@ -427,14 +454,18 @@ class Camera(object):
         anti_alias_width = self.anti_alias_width / (ph / fh)
         # Orient light
         rotation = frame.get_inverse_camera_rotation_matrix()
-        light_pos = self.light_source.get_location()
-        light_pos = np.dot(rotation, light_pos)
+        offset = frame.get_center()
+        light_pos = np.dot(
+            rotation, self.light_source.get_location() + offset
+        )
+        cam_pos = self.frame.get_implied_camera_location()  # TODO
 
         self.perspective_uniforms = {
             "frame_shape": frame.get_shape(),
             "anti_alias_width": anti_alias_width,
-            "camera_center": tuple(frame.get_center()),
+            "camera_offset": tuple(offset),
             "camera_rotation": tuple(np.array(rotation).T.flatten()),
+            "camera_position": tuple(cam_pos),
             "light_source_position": tuple(light_pos),
             "focal_distance": frame.get_focal_distance(),
         }
@@ -445,6 +476,8 @@ class Camera(object):
 
     def get_texture_id(self, path):
         if path not in self.path_to_texture:
+            if self.n_textures == 15:  # I have no clue why this is needed
+                self.n_textures += 1
             tid = self.n_textures
             self.n_textures += 1
             im = Image.open(path).convert("RGBA")
@@ -468,4 +501,5 @@ class Camera(object):
 class ThreeDCamera(Camera):
     CONFIG = {
         "samples": 4,
+        "anti_alias_width": 0,
     }

manimlib/config.py

@@ -5,6 +5,7 @@ import importlib
 import os
 import sys
 import yaml
+from contextlib import contextmanager
 from screeninfo import get_monitors
 
 from manimlib.utils.config_ops import merge_dicts_recursively
@@ -12,6 +13,9 @@ from manimlib.utils.init_config import init_customization
 from manimlib.logger import log
 
 
+__config_file__ = "custom_config.yml"
+
+
 def parse_cli():
     try:
         parser = argparse.ArgumentParser()
@@ -112,6 +116,12 @@ def parse_cli():
                  "in two comma separated values, e.g. \"3,6\", it will end"
                  "the rendering at the second value",
         )
+        parser.add_argument(
+            "-e", "--embed", metavar="LINENO",
+            help="Takes a line number as an argument, and results"
+                 "in the scene being called as if the line `self.embed()`"
+                 "was inserted into the scene code at that line number."
+        )
         parser.add_argument(
             "-r", "--resolution",
             help="Resolution, passed as \"WxH\", e.g. \"1920x1080\"",
@@ -142,6 +152,10 @@ def parse_cli():
             action="store_true",
             help="Display the version of manimgl"
         )
+        parser.add_argument(
+            "--log-level",
+            help="Level of messages to Display, can be DEBUG / INFO / WARNING / ERROR / CRITICAL"
+        )
         args = parser.parse_args()
         return args
     except argparse.ArgumentError as err:
@@ -158,14 +172,30 @@ def get_manim_dir():
 def get_module(file_name):
     if file_name is None:
         return None
-    else:
-        module_name = file_name.replace(os.sep, ".").replace(".py", "")
-        spec = importlib.util.spec_from_file_location(module_name, file_name)
-        module = importlib.util.module_from_spec(spec)
-        spec.loader.exec_module(module)
-        return module
+    module_name = file_name.replace(os.sep, ".").replace(".py", "")
+    spec = importlib.util.spec_from_file_location(module_name, file_name)
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+@contextmanager
+def insert_embed_line(file_name, lineno):
+    with open(file_name, 'r') as fp:
+        lines = fp.readlines()
+    line = lines[lineno - 1]
+    n_spaces = len(line) - len(line.lstrip())
+    lines.insert(lineno, " " * n_spaces + "self.embed()\n")
+
+    alt_file = file_name.replace(".py", "_inserted_embed.py")
+    with open(alt_file, 'w') as fp:
+        fp.writelines(lines)
+
+    try:
+        yield alt_file
+    finally:
+        os.remove(alt_file)
 
-__config_file__ = "custom_config.yml"
 
 def get_custom_config():
     global __config_file__
@@ -193,9 +223,11 @@ def get_custom_config():
 
 def check_temporary_storage(config):
     if config["directories"]["temporary_storage"] == "" and sys.platform == "win32":
-        log.warning("You may be using Windows platform and have not specified the path of"
+        log.warning(
+            "You may be using Windows platform and have not specified the path of"
             " `temporary_storage`, which may cause OSError. So it is recommended"
-            " to specify the `temporary_storage` in the config file (.yml)")
+            " to specify the `temporary_storage` in the config file (.yml)"
+        )
 
 
 def get_configuration(args):
@@ -225,8 +257,10 @@ def get_configuration(args):
 
     elif not os.path.exists(__config_file__):
         log.info(f"Using the default configuration file, which you can modify in `{global_defaults_file}`")
-        log.info("If you want to create a local configuration file, you can create a file named"
-            f" `{__config_file__}`, or run `manimgl --config`")
+        log.info(
+            "If you want to create a local configuration file, you can create a file named"
+            f" `{__config_file__}`, or run `manimgl --config`"
+        )
 
     custom_config = get_custom_config()
     check_temporary_storage(custom_config)
@@ -256,16 +290,22 @@ def get_configuration(args):
         "quiet": args.quiet,
     }
 
-    module = get_module(args.file)
+    if args.embed is None:
+        module = get_module(args.file)
+    else:
+        with insert_embed_line(args.file, int(args.embed)) as alt_file:
+            module = get_module(alt_file)
+
     config = {
         "module": module,
         "scene_names": args.scene_names,
         "file_writer_config": file_writer_config,
         "quiet": args.quiet or args.write_all,
         "write_all": args.write_all,
+        "skip_animations": args.skip_animations,
         "start_at_animation_number": args.start_at_animation_number,
-        "preview": not write_file,
         "end_at_animation_number": None,
+        "preview": not write_file,
         "leave_progress_bars": args.leave_progress_bars,
     }
 
@@ -278,7 +318,7 @@ def get_configuration(args):
     mon_index = custom_config["window_monitor"]
     monitor = monitors[min(mon_index, len(monitors) - 1)]
     window_width = monitor.width
-    if not args.full_screen:
+    if not (args.full_screen or custom_config["full_screen"]):
         window_width //= 2
     window_height = window_width * 9 // 16
     config["window_config"] = {
@@ -295,10 +335,6 @@ def get_configuration(args):
         else:
             config["start_at_animation_number"] = int(stan)
 
-    config["skip_animations"] = any([
-        args.skip_animations,
-        args.start_at_animation_number,
-    ])
     return config
 
 

manimlib/default_config.yml

@@ -34,6 +34,7 @@ style:
 # the window on the monitor, e.g. "960,540"
 window_position: UR
 window_monitor: 0
+full_screen: False
 # If break_into_partial_movies is set to True, then many small
 # files will be written corresponding to each Scene.play and
 # Scene.wait call, and these files will then be combined

manimlib/extract_scene.py

@@ -1,5 +1,6 @@
 import inspect
 import sys
+import copy
 
 from manimlib.scene.scene import Scene
 from manimlib.config import get_custom_config
@@ -38,7 +39,7 @@ def prompt_user_for_choice(scene_classes):
             "\nScene Name or Number: "
         )
         return [
-            name_to_class[split_str] if not split_str.isnumeric() else scene_classes[int(split_str)-1]
+            name_to_class[split_str] if not split_str.isnumeric() else scene_classes[int(split_str) - 1]
             for split_str in user_input.replace(" ", "").split(",")
         ]
     except IndexError:
@@ -67,6 +68,26 @@ def get_scene_config(config):
     ])
 
 
+def compute_total_frames(scene_class, scene_config):
+    """
+    When a scene is being written to file, a copy of the scene is run with
+    skip_animations set to true so as to count how many frames it will require.
+    This allows for a total progress bar on rendering, and also allows runtime
+    errors to be exposed preemptively for long running scenes. The final frame
+    is saved by default, so that one can more quickly check that the last frame
+    looks as expected.
+    """
+    pre_config = copy.deepcopy(scene_config)
+    pre_config["file_writer_config"]["write_to_movie"] = False
+    pre_config["file_writer_config"]["save_last_frame"] = True
+    pre_config["file_writer_config"]["quiet"] = True
+    pre_config["skip_animations"] = True
+    pre_scene = scene_class(**pre_config)
+    pre_scene.run()
+    total_time = pre_scene.time - pre_scene.skip_time
+    return int(total_time * scene_config["camera_config"]["frame_rate"])
+
+
 def get_scenes_to_render(scene_classes, scene_config, config):
     if config["write_all"]:
         return [sc(**scene_config) for sc in scene_classes]
@@ -76,6 +97,9 @@ def get_scenes_to_render(scene_classes, scene_config, config):
         found = False
         for scene_class in scene_classes:
             if scene_class.__name__ == scene_name:
+                fw_config = scene_config["file_writer_config"]
+                if fw_config["write_to_movie"]:
+                    fw_config["total_frames"] = compute_total_frames(scene_class, scene_config)
                 scene = scene_class(**scene_config)
                 result.append(scene)
                 found = True

manimlib/logger.py

@@ -6,7 +6,8 @@ __all__ = ["log"]
 
 FORMAT = "%(message)s"
 logging.basicConfig(
-    level="NOTSET", format=FORMAT, datefmt="[%X]", handlers=[RichHandler()]
+    level=logging.WARNING, format=FORMAT, datefmt="[%X]", handlers=[RichHandler()]
 )
 
-log = logging.getLogger("rich")
+log = logging.getLogger("manimgl")
+log.setLevel("DEBUG")

manimlib/mobject/boolean_ops.py

@@ -0,0 +1,116 @@
+import numpy as np
+import pathops
+
+from manimlib.mobject.types.vectorized_mobject import VMobject
+
+
+# Boolean operations between 2D mobjects
+# Borrowed from from https://github.com/ManimCommunity/manim/
+
+def _convert_vmobject_to_skia_path(vmobject):
+    path = pathops.Path()
+    subpaths = vmobject.get_subpaths_from_points(vmobject.get_all_points())
+    for subpath in subpaths:
+        quads = vmobject.get_bezier_tuples_from_points(subpath)
+        start = subpath[0]
+        path.moveTo(*start[:2])
+        for p0, p1, p2 in quads:
+            path.quadTo(*p1[:2], *p2[:2])
+        if vmobject.consider_points_equals(subpath[0], subpath[-1]):
+            path.close()
+    return path
+
+
+def _convert_skia_path_to_vmobject(path, vmobject):
+    PathVerb = pathops.PathVerb
+    current_path_start = np.array([0.0, 0.0, 0.0])
+    for path_verb, points in path:
+        if path_verb == PathVerb.CLOSE:
+            vmobject.add_line_to(current_path_start)
+        else:
+            points = np.hstack((np.array(points), np.zeros((len(points), 1))))
+            if path_verb == PathVerb.MOVE:
+                for point in points:
+                    current_path_start = point
+                    vmobject.start_new_path(point)
+            elif path_verb == PathVerb.CUBIC:
+                vmobject.add_cubic_bezier_curve_to(*points)
+            elif path_verb == PathVerb.LINE:
+                vmobject.add_line_to(points[0])
+            elif path_verb == PathVerb.QUAD:
+                vmobject.add_quadratic_bezier_curve_to(*points)
+            else:
+                raise Exception(f"Unsupported: {path_verb}")
+    return vmobject
+
+
+class Union(VMobject):
+    def __init__(self, *vmobjects, **kwargs):
+        if len(vmobjects) < 2:
+            raise ValueError("At least 2 mobjects needed for Union.")
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        paths = [
+            _convert_vmobject_to_skia_path(vmobject)
+            for vmobject in vmobjects
+        ]
+        pathops.union(paths, outpen.getPen())
+        _convert_skia_path_to_vmobject(outpen, self)
+
+
+class Difference(VMobject):
+    def __init__(self, subject, clip, **kwargs):
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        pathops.difference(
+            [_convert_vmobject_to_skia_path(subject)],
+            [_convert_vmobject_to_skia_path(clip)],
+            outpen.getPen(),
+        )
+        _convert_skia_path_to_vmobject(outpen, self)
+
+
+class Intersection(VMobject):
+    def __init__(self, *vmobjects, **kwargs):
+        if len(vmobjects) < 2:
+            raise ValueError("At least 2 mobjects needed for Intersection.")
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        pathops.intersection(
+            [_convert_vmobject_to_skia_path(vmobjects[0])],
+            [_convert_vmobject_to_skia_path(vmobjects[1])],
+            outpen.getPen(),
+        )
+        new_outpen = outpen
+        for _i in range(2, len(vmobjects)):
+            new_outpen = pathops.Path()
+            pathops.intersection(
+                [outpen],
+                [_convert_vmobject_to_skia_path(vmobjects[_i])],
+                new_outpen.getPen(),
+            )
+            outpen = new_outpen
+        _convert_skia_path_to_vmobject(outpen, self)
+
+
+class Exclusion(VMobject):
+    def __init__(self, *vmobjects, **kwargs):
+        if len(vmobjects) < 2:
+            raise ValueError("At least 2 mobjects needed for Exclusion.")
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        pathops.xor(
+            [_convert_vmobject_to_skia_path(vmobjects[0])],
+            [_convert_vmobject_to_skia_path(vmobjects[1])],
+            outpen.getPen(),
+        )
+        new_outpen = outpen
+        for _i in range(2, len(vmobjects)):
+            new_outpen = pathops.Path()
+            pathops.xor(
+                [outpen],
+                [_convert_vmobject_to_skia_path(vmobjects[_i])],
+                new_outpen.getPen(),
+            )
+            outpen = new_outpen
+        _convert_skia_path_to_vmobject(outpen, self)

manimlib/mobject/coordinate_systems.py

@@ -151,14 +151,14 @@ class CoordinateSystem():
         else:
             alpha = binary_search(
                 function=lambda a: self.point_to_coords(
-                    graph.point_from_proportion(a)
+                    graph.quick_point_from_proportion(a)
                 )[0],
                 target=x,
                 lower_bound=self.x_range[0],
                 upper_bound=self.x_range[1],
             )
             if alpha is not None:
-                return graph.point_from_proportion(alpha)
+                return graph.quick_point_from_proportion(alpha)
             else:
                 return None
 

manimlib/mobject/geometry.py

@@ -305,6 +305,9 @@ class Circle(Arc):
             (angle - start_angle) / TAU
         )
 
+    def get_radius(self):
+        return get_norm(self.get_start() - self.get_center())
+
 
 class Dot(Circle):
     CONFIG = {
@@ -507,6 +510,7 @@ class Line(TipableVMobject):
 
     def set_length(self, length, **kwargs):
         self.scale(length / self.get_length(), **kwargs)
+        return self
 
 
 class DashedLine(Line):

manimlib/mobject/mobject.py

@@ -43,10 +43,13 @@ class Mobject(object):
         "opacity": 1,
         "dim": 3,  # TODO, get rid of this
         # Lighting parameters
-        # Positive gloss up to 1 makes it reflect the light.
-        "gloss": 0.0,
-        # Positive shadow up to 1 makes a side opposite the light darker
+        # ...
+        # Larger reflectiveness makes things brighter when facing the light
+        "reflectiveness": 0.0,
+        # Larger shadow makes faces opposite the light darker
         "shadow": 0.0,
+        # Makes parts bright where light gets reflected toward the camera
+        "gloss": 0.0,
         # For shaders
         "shader_folder": "",
         "render_primitive": moderngl.TRIANGLE_STRIP,
@@ -82,6 +85,14 @@ class Mobject(object):
     def __str__(self):
         return self.__class__.__name__
 
+    def __add__(self, other: 'Mobject') -> 'Mobject':
+        assert(isinstance(other, Mobject))
+        return self.get_group_class()(self, other)
+
+    def __mul__(self, other: 'int') -> 'Mobject':
+        assert(isinstance(other, int))
+        return self.replicate(other)
+
     def init_data(self):
         self.data = {
             "points": np.zeros((0, 3)),
@@ -94,6 +105,7 @@ class Mobject(object):
             "is_fixed_in_frame": float(self.is_fixed_in_frame),
             "gloss": self.gloss,
             "shadow": self.shadow,
+            "reflectiveness": self.reflectiveness,
         }
 
     def init_colors(self):
@@ -145,6 +157,7 @@ class Mobject(object):
         for mob in self.get_family():
             for key in mob.data:
                 mob.data[key] = mob.data[key][::-1]
+        self.refresh_unit_normal()
         return self
 
     def apply_points_function(self, func, about_point=None, about_edge=ORIGIN, works_on_bounding_box=False):
@@ -300,6 +313,11 @@ class Mobject(object):
         self.assemble_family()
         return self
 
+    def insert_submobject(self, index, new_submob):
+        self.submobjects.insert(index, new_submob)
+        self.assemble_family()
+        return self
+
     def set_submobjects(self, submobject_list):
         self.remove(*self.submobjects)
         self.add(*submobject_list)
@@ -386,6 +404,7 @@ class Mobject(object):
             self.submobjects.sort(key=submob_func)
         else:
             self.submobjects.sort(key=lambda m: point_to_num_func(m.get_center()))
+        self.assemble_family()
         return self
 
     def shuffle(self, recurse=False):
@@ -393,6 +412,7 @@ class Mobject(object):
             for submob in self.submobjects:
                 submob.shuffle(recurse=True)
         random.shuffle(self.submobjects)
+        self.assemble_family()
         return self
 
     # Copying
@@ -767,7 +787,7 @@ class Mobject(object):
         return self.rescale_to_fit(height, 1, stretch=True, **kwargs)
 
     def stretch_to_fit_depth(self, depth, **kwargs):
-        return self.rescale_to_fit(depth, 1, stretch=True, **kwargs)
+        return self.rescale_to_fit(depth, 2, stretch=True, **kwargs)
 
     def set_width(self, width, stretch=False, **kwargs):
         return self.rescale_to_fit(width, 0, stretch=stretch, **kwargs)
@@ -966,12 +986,12 @@ class Mobject(object):
     def fade(self, darkness=0.5, recurse=True):
         self.set_opacity(1.0 - darkness, recurse=recurse)
 
-    def get_gloss(self):
-        return self.uniforms["gloss"]
+    def get_reflectiveness(self):
+        return self.uniforms["reflectiveness"]
 
-    def set_gloss(self, gloss, recurse=True):
+    def set_reflectiveness(self, reflectiveness, recurse=True):
         for mob in self.get_family(recurse):
-            mob.uniforms["gloss"] = gloss
+            mob.uniforms["reflectiveness"] = reflectiveness
         return self
 
     def get_shadow(self):
@@ -982,6 +1002,14 @@ class Mobject(object):
             mob.uniforms["shadow"] = shadow
         return self
 
+    def get_gloss(self):
+        return self.uniforms["gloss"]
+
+    def set_gloss(self, gloss, recurse=True):
+        for mob in self.get_family(recurse):
+            mob.uniforms["gloss"] = gloss
+        return self
+
     # Background rectangle
 
     def add_background_rectangle(self, color=None, opacity=0.75, **kwargs):
@@ -1363,11 +1391,13 @@ class Mobject(object):
     @affects_shader_info_id
     def fix_in_frame(self):
         self.uniforms["is_fixed_in_frame"] = 1.0
+        self.is_fixed_in_frame = True
         return self
 
     @affects_shader_info_id
     def unfix_from_frame(self):
         self.uniforms["is_fixed_in_frame"] = 0.0
+        self.is_fixed_in_frame = False
         return self
 
     @affects_shader_info_id
@@ -1610,6 +1640,10 @@ class Group(Mobject):
         Mobject.__init__(self, **kwargs)
         self.add(*mobjects)
 
+    def __add__(self, other: 'Mobject' or 'Group'):
+        assert(isinstance(other, Mobject))
+        return self.add(other)
+
 
 class Point(Mobject):
     CONFIG = {

manimlib/mobject/svg/drawings.py

@@ -200,12 +200,11 @@ class Laptop(VGroup):
 
 class VideoIcon(SVGMobject):
     CONFIG = {
-        "file_name": "video_icon",
         "width": FRAME_WIDTH / 12.,
     }
 
     def __init__(self, **kwargs):
-        SVGMobject.__init__(self, **kwargs)
+        super().__init__(file_name="video_icon", **kwargs)
         self.center()
         self.set_width(self.width)
         self.set_stroke(color=WHITE, width=0)

manimlib/mobject/svg/mtex_mobject.py

@@ -0,0 +1,521 @@
+import itertools as it
+import re
+from types import MethodType
+
+from manimlib.mobject.svg.svg_mobject import SVGMobject
+from manimlib.mobject.types.vectorized_mobject import VMobject
+from manimlib.mobject.types.vectorized_mobject import VGroup
+from manimlib.utils.iterables import adjacent_pairs
+from manimlib.utils.iterables import remove_list_redundancies
+from manimlib.utils.tex_file_writing import tex_to_svg_file
+from manimlib.utils.tex_file_writing import get_tex_config
+from manimlib.utils.tex_file_writing import display_during_execution
+
+
+SCALE_FACTOR_PER_FONT_POINT = 0.001
+
+
+tex_hash_to_mob_map = {}
+
+
+def _get_neighbouring_pairs(iterable):
+    return list(adjacent_pairs(iterable))[:-1]
+
+
+class _LabelledTex(SVGMobject):
+    CONFIG = {
+        "height": None,
+        "path_string_config": {
+            "should_subdivide_sharp_curves": True,
+            "should_remove_null_curves": True,
+        },
+    }
+
+    @staticmethod
+    def color_str_to_label(color_str):
+        if len(color_str) == 4:
+            # "#RGB" => "#RRGGBB"
+            color_str = "#" + "".join([c * 2 for c in color_str[1:]])
+        return int(color_str[1:], 16) - 1
+
+    def get_mobjects_from(self, element):
+        result = super().get_mobjects_from(element)
+        for mob in result:
+            if not hasattr(mob, "glyph_label"):
+                mob.glyph_label = -1
+        try:
+            color_str = element.getAttribute("fill")
+            if color_str:
+                glyph_label = _LabelledTex.color_str_to_label(color_str)
+                for mob in result:
+                    mob.glyph_label = glyph_label
+        except:
+            pass
+        return result
+
+
+class _TexSpan(object):
+    def __init__(self, script_type, label):
+        # script_type: 0 for normal, 1 for subscript, 2 for superscript.
+        # Only those spans with `script_type == 0` will be colored.
+        self.script_type = script_type
+        self.label = label
+        self.containing_labels = []
+
+    def __repr__(self):
+        return "_TexSpan(" + ", ".join([
+            attrib_name + "=" + str(getattr(self, attrib_name))
+            for attrib_name in ["script_type", "label", "containing_labels"]
+        ]) + ")"
+
+
+class _TexParser(object):
+    def __init__(self, mtex):
+        self.tex_string = mtex.tex_string
+        strings_to_break_up = remove_list_redundancies([
+            *mtex.isolate, *mtex.tex_to_color_map.keys(), mtex.tex_string
+        ])
+        if "" in strings_to_break_up:
+            strings_to_break_up.remove("")
+        unbreakable_commands = mtex.unbreakable_commands
+
+        self.tex_spans_dict = {}
+        self.current_label = 0
+        self.break_up_by_braces()
+        self.break_up_by_scripts()
+        self.break_up_by_additional_strings(strings_to_break_up)
+        self.merge_unbreakable_commands(unbreakable_commands)
+        self.analyse_containing_labels()
+
+    @staticmethod
+    def label_to_color_tuple(n):
+        # Get a unique color different from black,
+        # or the svg file will not include the color information.
+        rgb = n + 1
+        rg, b = divmod(rgb, 256)
+        r, g = divmod(rg, 256)
+        return r, g, b
+
+    @staticmethod
+    def contains(span_0, span_1):
+        return span_0[0] <= span_1[0] and span_1[1] <= span_0[1]
+
+    def add_tex_span(self, span_tuple, script_type=0, label=-1):
+        if script_type == 0:
+            # Should be additionally labelled.
+            label = self.current_label
+            self.current_label += 1
+
+        tex_span = _TexSpan(script_type, label)
+        self.tex_spans_dict[span_tuple] = tex_span
+
+    def break_up_by_braces(self):
+        tex_string = self.tex_string
+        span_tuples = []
+        left_brace_indices = []
+        for match_obj in re.finditer(r"(\\*)(\{|\})", tex_string):
+            # Braces following even numbers of backslashes are counted.
+            if len(match_obj.group(1)) % 2 == 1:
+                continue
+            if match_obj.group(2) == "{":
+                left_brace_index = match_obj.span(2)[0]
+                left_brace_indices.append(left_brace_index)
+            else:
+                left_brace_index = left_brace_indices.pop()
+                right_brace_index = match_obj.span(2)[1]
+                span_tuples.append((left_brace_index, right_brace_index))
+        if left_brace_indices:
+            self.raise_tex_parsing_error()
+
+        self.paired_braces_tuples = span_tuples
+        for span_tuple in span_tuples:
+            self.add_tex_span(span_tuple)
+
+    def break_up_by_scripts(self):
+        tex_string = self.tex_string
+        brace_indices_dict = dict(self.tex_spans_dict.keys())
+        for match_obj in re.finditer(r"((?<!\\)(_|\^)\s*)|(\s+(_|\^)\s*)", tex_string):
+            script_type = 1 if "_" in match_obj.group() else 2
+            token_begin, token_end = match_obj.span()
+            if token_end in brace_indices_dict:
+                content_span = (token_end, brace_indices_dict[token_end])
+            else:
+                content_match_obj = re.match(r"\w|\\[a-zA-Z]+", tex_string[token_end:])
+                if not content_match_obj:
+                    self.raise_tex_parsing_error()
+                content_span = tuple([
+                    index + token_end for index in content_match_obj.span()
+                ])
+                self.add_tex_span(content_span)
+            label = self.tex_spans_dict[content_span].label
+            self.add_tex_span(
+                (token_begin, content_span[1]),
+                script_type=script_type,
+                label=label
+            )
+
+    def break_up_by_additional_strings(self, strings_to_break_up):
+        tex_string = self.tex_string
+        all_span_tuples = []
+        for string in strings_to_break_up:
+            # Only matches non-crossing strings.
+            for match_obj in re.finditer(re.escape(string), tex_string):
+                all_span_tuples.append(match_obj.span())
+
+        script_spans_dict = dict([
+            span_tuple[::-1]
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if tex_span.script_type != 0
+        ])
+        for span_begin, span_end in all_span_tuples:
+            if span_end in script_spans_dict.values():
+                # Deconstruct spans with subscripts & superscripts.
+                while span_end in script_spans_dict:
+                    span_end = script_spans_dict[span_end]
+                if span_begin >= span_end:
+                    continue
+            span_tuple = (span_begin, span_end)
+            if span_tuple not in self.tex_spans_dict:
+                self.add_tex_span(span_tuple)
+
+    def merge_unbreakable_commands(self, unbreakable_commands):
+        tex_string = self.tex_string
+        command_merge_spans = []
+        brace_indices_dict = dict(self.paired_braces_tuples)
+        # Braces leading by `unbreakable_commands` shouldn't be marked.
+        for command in unbreakable_commands:
+            for match_obj in re.finditer(re.escape(command), tex_string):
+                merge_begin_index = match_obj.span()[1]
+                merge_end_index = merge_begin_index
+                if merge_end_index not in brace_indices_dict:
+                    continue
+                while merge_end_index in brace_indices_dict:
+                    merge_end_index = brace_indices_dict[merge_end_index]
+                command_merge_spans.append((merge_begin_index, merge_end_index))
+
+        self.tex_spans_dict = {
+            span_tuple: tex_span
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if all([
+                not _TexParser.contains(merge_span, span_tuple)
+                for merge_span in command_merge_spans
+            ])
+        }
+
+    def analyse_containing_labels(self):
+        for span_0, tex_span_0 in self.tex_spans_dict.items():
+            if tex_span_0.script_type != 0:
+                continue
+            for span_1, tex_span_1 in self.tex_spans_dict.items():
+                if _TexParser.contains(span_1, span_0):
+                    tex_span_1.containing_labels.append(tex_span_0.label)
+
+    def get_labelled_expression(self):
+        tex_string = self.tex_string
+        if not self.tex_spans_dict:
+            return tex_string
+
+        indices_with_labels = sorted([
+            (span_tuple[i], i, span_tuple[1 - i], tex_span.label)
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if tex_span.script_type == 0
+            for i in range(2)
+        ], key=lambda t: (t[0], -t[1], -t[2]))
+        # Add one more item to ensure all the substrings are joined.
+        indices_with_labels.append((len(tex_string), 0, 0, 0))
+
+        result = tex_string[: indices_with_labels[0][0]]
+        index_with_label_pairs = _get_neighbouring_pairs(indices_with_labels)
+        for index_with_label, next_index_with_label in index_with_label_pairs:
+            index, flag, _, label = index_with_label
+            next_index, *_ = next_index_with_label
+            # Adding one more pair of braces will help maintain the glyghs of tex file...
+            if flag == 0:
+                color_tuple = _TexParser.label_to_color_tuple(label)
+                result += "".join([
+                    "{{",
+                    "\\color[RGB]",
+                    "{",
+                    ",".join(map(str, color_tuple)),
+                    "}"
+                ])
+            else:
+                result += "}}"
+            result += tex_string[index : next_index]
+        return result
+
+    def raise_tex_parsing_error(self):
+        raise ValueError(f"Failed to parse tex: \"{self.tex_string}\"")
+
+
+class MTex(VMobject):
+    CONFIG = {
+        "fill_opacity": 1.0,
+        "stroke_width": 0,
+        "should_center": True,
+        "font_size": 48,
+        "height": None,
+        "organize_left_to_right": False,
+        "alignment": "\\centering",
+        "tex_environment": "align*",
+        "isolate": [],
+        "unbreakable_commands": ["\\begin", "\\end"],
+        "tex_to_color_map": {},
+    }
+
+    def __init__(self, tex_string, **kwargs):
+        super().__init__(**kwargs)
+        self.tex_string = MTex.modify_tex_string(tex_string)
+
+        tex_parser = _TexParser(self)
+        self.tex_spans_dict = tex_parser.tex_spans_dict
+
+        new_tex = tex_parser.get_labelled_expression()
+        full_tex = self.get_tex_file_body(new_tex)
+        hash_val = hash(full_tex)
+        if hash_val not in tex_hash_to_mob_map:
+            with display_during_execution(f"Writing \"{tex_string}\""):
+                filename = tex_to_svg_file(full_tex)
+                svg_mob = _LabelledTex(filename)
+                tex_hash_to_mob_map[hash_val] = svg_mob
+        self.add(*[
+            submob.copy()
+            for submob in tex_hash_to_mob_map[hash_val]
+        ])
+        self.build_submobjects()
+
+        self.init_colors()
+        self.set_color_by_tex_to_color_map(self.tex_to_color_map)
+
+        if self.height is None:
+            self.scale(SCALE_FACTOR_PER_FONT_POINT * self.font_size)
+        if self.organize_left_to_right:
+            self.organize_submobjects_left_to_right()
+
+    @staticmethod
+    def modify_tex_string(tex_string):
+        result = tex_string.strip("\n")
+        # Prevent from passing an empty string.
+        if not result:
+            result = "\\quad"
+        return result
+
+    def get_tex_file_body(self, new_tex):
+        if self.tex_environment:
+            new_tex = "\n".join([
+                f"\\begin{{{self.tex_environment}}}",
+                new_tex,
+                f"\\end{{{self.tex_environment}}}"
+            ])
+        if self.alignment:
+            new_tex = "\n".join([self.alignment, new_tex])
+
+        tex_config = get_tex_config()
+        return tex_config["tex_body"].replace(
+            tex_config["text_to_replace"],
+            new_tex
+        )
+
+    def build_submobjects(self):
+        if not self.submobjects:
+            return
+        self.group_submobjects()
+        self.sort_scripts_in_tex_order()
+        self.assign_submob_tex_strings()
+
+    def group_submobjects(self):
+        # Simply pack together adjacent mobjects with the same label.
+        new_submobjects = []
+        def append_new_submobject(glyphs):
+            if glyphs:
+                submobject = VGroup(*glyphs)
+                submobject.submob_label = glyphs[0].glyph_label
+                new_submobjects.append(submobject)
+
+        new_glyphs = []
+        current_glyph_label = -1
+        for submob in self.submobjects:
+            if submob.glyph_label == current_glyph_label:
+                new_glyphs.append(submob)
+            else:
+                append_new_submobject(new_glyphs)
+                new_glyphs = [submob]
+                current_glyph_label = submob.glyph_label
+        append_new_submobject(new_glyphs)
+        self.set_submobjects(new_submobjects)
+
+    def sort_scripts_in_tex_order(self):
+        # LaTeX always puts superscripts before subscripts.
+        # This function sorts the submobjects of scripts in the order of tex given.
+        index_and_span_list = sorted([
+            (index, span_tuple)
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if tex_span.script_type != 0
+            for index in span_tuple
+        ])
+        index_and_span_pair = _get_neighbouring_pairs(index_and_span_list)
+        for index_and_span_0, index_and_span_1 in index_and_span_pair:
+            index_0, span_tuple_0 = index_and_span_0
+            index_1, span_tuple_1 = index_and_span_1
+            if index_0 != index_1:
+                continue
+            if not all([
+                self.tex_spans_dict[span_tuple_0].script_type == 1,
+                self.tex_spans_dict[span_tuple_1].script_type == 2
+            ]):
+                continue
+            submob_slice_0 = self.slice_of_part(
+                self.get_part_by_span_tuples([span_tuple_0])
+            )
+            submob_slice_1 = self.slice_of_part(
+                self.get_part_by_span_tuples([span_tuple_1])
+            )
+            submobs = self.submobjects
+            self.set_submobjects([
+                *submobs[: submob_slice_1.start],
+                *submobs[submob_slice_0],
+                *submobs[submob_slice_1.stop : submob_slice_0.start],
+                *submobs[submob_slice_1],
+                *submobs[submob_slice_0.stop :]
+            ])
+
+    def assign_submob_tex_strings(self):
+        # Not sure whether this is the best practice...
+        # Just a temporary hack for supporting `TransformMatchingTex`.
+        tex_string = self.tex_string
+        # Use tex strings including "_", "^".
+        label_dict = {}
+        for span_tuple, tex_span in self.tex_spans_dict.items():
+            if tex_span.script_type != 0:
+                label_dict[tex_span.label] = span_tuple
+            else:
+                if tex_span.label not in label_dict:
+                    label_dict[tex_span.label] = span_tuple
+
+        curr_labels = [submob.submob_label for submob in self.submobjects]
+        prev_labels = [curr_labels[-1], *curr_labels[:-1]]
+        next_labels = [*curr_labels[1:], curr_labels[0]]
+        tex_string_spans = []
+        for curr_label, prev_label, next_label in zip(
+            curr_labels, prev_labels, next_labels
+        ):
+            curr_span_tuple = label_dict[curr_label]
+            prev_span_tuple = label_dict[prev_label]
+            next_span_tuple = label_dict[next_label]
+            containing_labels = self.tex_spans_dict[curr_span_tuple].containing_labels
+            tex_string_spans.append([
+                prev_span_tuple[1] if prev_label in containing_labels else curr_span_tuple[0],
+                next_span_tuple[0] if next_label in containing_labels else curr_span_tuple[1]
+            ])
+        tex_string_spans[0][0] = label_dict[curr_labels[0]][0]
+        tex_string_spans[-1][1] = label_dict[curr_labels[-1]][1]
+        for submob, tex_string_span in zip(self.submobjects, tex_string_spans):
+            submob.tex_string = tex_string[slice(*tex_string_span)]
+            # Support `get_tex()` method here.
+            submob.get_tex = MethodType(lambda inst: inst.tex_string, submob)
+
+    def get_part_by_span_tuples(self, span_tuples):
+        labels = remove_list_redundancies(list(it.chain(*[
+            self.tex_spans_dict[span_tuple].containing_labels
+            for span_tuple in span_tuples
+        ])))
+        return VGroup(*filter(
+            lambda submob: submob.submob_label in labels,
+            self.submobjects
+        ))
+
+    def find_span_components_of_custom_span(self, custom_span_tuple, partial_result=[]):
+        span_begin, span_end = custom_span_tuple
+        if span_begin == span_end:
+            return partial_result
+        next_begin_choices = sorted([
+            span_tuple[1]
+            for span_tuple in self.tex_spans_dict.keys()
+            if span_tuple[0] == span_begin and span_tuple[1] <= span_end
+        ], reverse=True)
+        for next_begin in next_begin_choices:
+            result = self.find_span_components_of_custom_span(
+                (next_begin, span_end), [*partial_result, (span_begin, next_begin)]
+            )
+            if result is not None:
+                return result
+        return None
+
+    def get_part_by_custom_span_tuple(self, custom_span_tuple):
+        span_tuples = self.find_span_components_of_custom_span(custom_span_tuple)
+        if span_tuples is None:
+            tex = self.tex_string[slice(*custom_span_tuple)]
+            raise ValueError(f"Failed to get span of tex: \"{tex}\"")
+        return self.get_part_by_span_tuples(span_tuples)
+
+    def get_parts_by_tex(self, tex):
+        return VGroup(*[
+            self.get_part_by_custom_span_tuple(match_obj.span())
+            for match_obj in re.finditer(re.escape(tex), self.tex_string)
+        ])
+
+    def get_part_by_tex(self, tex, index=0):
+        all_parts = self.get_parts_by_tex(tex)
+        return all_parts[index]
+
+    def set_color_by_tex(self, tex, color):
+        self.get_parts_by_tex(tex).set_color(color)
+        return self
+
+    def set_color_by_tex_to_color_map(self, tex_to_color_map):
+        for tex, color in list(tex_to_color_map.items()):
+            self.set_color_by_tex(tex, color)
+        return self
+
+    def indices_of_part(self, part):
+        indices = [
+            i for i, submob in enumerate(self.submobjects)
+            if submob in part
+        ]
+        if not indices:
+            raise ValueError("Failed to find part in tex")
+        return indices
+
+    def indices_of_part_by_tex(self, tex, index=0):
+        part = self.get_part_by_tex(tex, index=index)
+        return self.indices_of_part(part)
+
+    def slice_of_part(self, part):
+        indices = self.indices_of_part(part)
+        return slice(indices[0], indices[-1] + 1)
+
+    def slice_of_part_by_tex(self, tex, index=0):
+        part = self.get_part_by_tex(tex, index=index)
+        return self.slice_of_part(part)
+
+    def index_of_part(self, part):
+        return self.indices_of_part(part)[0]
+
+    def index_of_part_by_tex(self, tex, index=0):
+        part = self.get_part_by_tex(tex, index=index)
+        return self.index_of_part(part)
+
+    def get_tex(self):
+        return self.tex_string
+
+    def get_all_isolated_substrings(self):
+        tex_string = self.tex_string
+        return remove_list_redundancies([
+            tex_string[slice(*span_tuple)]
+            for span_tuple in self.tex_spans_dict.keys()
+        ])
+
+    def print_tex_strings_of_submobjects(self):
+        # For debugging
+        # Work with `index_labels()`
+        print("\n")
+        print(f"Submobjects of \"{self.get_tex()}\":")
+        for i, submob in enumerate(self.submobjects):
+            print(f"{i}: \"{submob.get_tex()}\"")
+        print("\n")
+
+
+class MTexText(MTex):
+    CONFIG = {
+        "tex_environment": None,
+    }

manimlib/mobject/svg/svg_mobject.py

@@ -345,10 +345,7 @@ class VMobjectFromSVGPathstring(VMobject):
             self.triangulation = np.load(tris_filepath)
             self.needs_new_triangulation = False
         else:
-            self.relative_point = np.array(ORIGIN)
-            for command, coord_string in self.get_commands_and_coord_strings():
-                new_points = self.string_to_points(command, coord_string)
-                self.handle_command(command, new_points)
+            self.handle_commands()
             if self.should_subdivide_sharp_curves:
                 # For a healthy triangulation later
                 self.subdivide_sharp_curves()
@@ -370,64 +367,40 @@ class VMobjectFromSVGPathstring(VMobject):
             re.split(pattern, self.path_string)[1:]
         )
 
-    def handle_command(self, command, new_points):
-        if command.islower():
-            # Treat it as a relative command
-            if command == "a":
-                # Only the last `self.dim` columns refer to points
-                new_points[:, -self.dim:] += self.relative_point
-            else:
-                new_points += self.relative_point
+    def handle_commands(self):
+        relative_point = ORIGIN
+        for command, coord_string in self.get_commands_and_coord_strings():
+            func, number_types_str = self.command_to_function(command)
+            upper_command = command.upper()
+            if upper_command == "Z":
+                func()  # `close_path` takes no arguments
+                continue
 
-        func, n_points = self.command_to_function(command)
-        command_points = new_points[:n_points]
-        if command.upper() == "A":
-            func(*command_points[0][:-self.dim], np.array(command_points[0][-self.dim:]))
-        else:
-            func(*command_points)
-        leftover_points = new_points[n_points:]
+            number_types = np.array(list(number_types_str))
+            n_numbers = len(number_types_str)
+            number_groups = np.array(string_to_numbers(coord_string)).reshape((-1, n_numbers))
 
-        # Recursively handle the rest of the points
-        if len(leftover_points) > 0:
-            if command.upper() == "M":
-                # Treat following points as relative line coordinates
-                command = "l"
-            if command.islower():
-                if command == "a":
-                    leftover_points[:, -self.dim:] -= self.relative_point
+            for numbers in number_groups:
+                if command.islower():
+                    # Treat it as a relative command
+                    numbers[number_types == "x"] += relative_point[0]
+                    numbers[number_types == "y"] += relative_point[1]
+
+                if upper_command == "A":
+                    args = [*numbers[:5], np.array([*numbers[5:7], 0.0])]
+                elif upper_command == "H":
+                    args = [np.array([numbers[0], relative_point[1], 0.0])]
+                elif upper_command == "V":
+                    args = [np.array([relative_point[0], numbers[0], 0.0])]
                 else:
-                    leftover_points -= self.relative_point
-                self.relative_point = self.get_last_point()
-            self.handle_command(command, leftover_points)
-        else:
-            # Command is over, reset for future relative commands
-            self.relative_point = self.get_last_point()
+                    args = list(np.hstack((
+                        numbers.reshape((-1, 2)), np.zeros((n_numbers // 2, 1))
+                    )))
+                func(*args)
+                relative_point = self.get_last_point()
 
-    def string_to_points(self, command, coord_string):
-        numbers = string_to_numbers(coord_string)
-        if command.upper() == "A":
-            # Only the last `self.dim` columns refer to points
-            # Each "point" returned here has a size of `(5 + self.dim)`
-            params = np.array(numbers).reshape((-1, 7))
-            result = np.zeros((params.shape[0], 5 + self.dim))
-            result[:, :7] = params
-            return result
-        if command.upper() in ["H", "V"]:
-            i = {"H": 0, "V": 1}[command.upper()]
-            xy = np.zeros((len(numbers), 2))
-            xy[:, i] = numbers
-            if command.isupper():
-                xy[:, 1 - i] = self.relative_point[1 - i]
-        else:
-            xy = np.array(numbers).reshape((-1, 2))
-        result = np.zeros((xy.shape[0], self.dim))
-        result[:, :2] = xy
-        return result
 
     def add_elliptical_arc_to(self, rx, ry, x_axis_rotation, large_arc_flag, sweep_flag, point):
-        """
-        In fact, this method only suits 2d VMobjects.
-        """
         def close_to_zero(a, threshold=1e-5):
             return abs(a) < threshold
 
@@ -536,19 +509,19 @@ class VMobjectFromSVGPathstring(VMobject):
     def get_command_to_function_map(self):
         """
         Associates svg command to VMobject function, and
-        the number of arguments it takes in
+        the types of arguments it takes in
         """
         return {
-            "M": (self.start_new_path, 1),
-            "L": (self.add_line_to, 1),
-            "H": (self.add_line_to, 1),
-            "V": (self.add_line_to, 1),
-            "C": (self.add_cubic_bezier_curve_to, 3),
-            "S": (self.add_smooth_cubic_curve_to, 2),
-            "Q": (self.add_quadratic_bezier_curve_to, 2),
-            "T": (self.add_smooth_curve_to, 1),
-            "A": (self.add_elliptical_arc_to, 1),
-            "Z": (self.close_path, 0),
+            "M": (self.start_new_path, "xy"),
+            "L": (self.add_line_to, "xy"),
+            "H": (self.add_line_to, "x"),
+            "V": (self.add_line_to, "y"),
+            "C": (self.add_cubic_bezier_curve_to, "xyxyxy"),
+            "S": (self.add_smooth_cubic_curve_to, "xyxy"),
+            "Q": (self.add_quadratic_bezier_curve_to, "xyxy"),
+            "T": (self.add_smooth_curve_to, "xy"),
+            "A": (self.add_elliptical_arc_to, "-----xy"),
+            "Z": (self.close_path, ""),
         }
 
     def get_original_path_string(self):

manimlib/mobject/svg/tex_mobject.py

@@ -129,15 +129,18 @@ class SingleStringTex(VMobject):
 
     def balance_braces(self, tex):
         """
-        Makes Tex resiliant to unmatched { at start
+        Makes Tex resiliant to unmatched braces
         """
-        num_lefts, num_rights = [tex.count(char) for char in "{}"]
-        while num_rights > num_lefts:
-            tex = "{" + tex
-            num_lefts += 1
-        while num_lefts > num_rights:
-            tex = tex + "}"
-            num_rights += 1
+        num_unclosed_brackets = 0
+        for char in tex:
+            if char == "{":
+                num_unclosed_brackets += 1
+            elif char == "}":
+                if num_unclosed_brackets == 0:
+                    tex = "{" + tex
+                else:
+                    num_unclosed_brackets -= 1
+        tex += num_unclosed_brackets * "}"
         return tex
 
     def get_tex(self):

manimlib/mobject/svg/text_mobject.py

@@ -1,4 +1,3 @@
-import copy
 import hashlib
 import os
 import re

manimlib/mobject/three_dimensions.py

@@ -6,6 +6,9 @@ from manimlib.mobject.types.surface import SGroup
 from manimlib.mobject.types.vectorized_mobject import VGroup
 from manimlib.mobject.types.vectorized_mobject import VMobject
 from manimlib.mobject.geometry import Square
+from manimlib.mobject.geometry import Polygon
+from manimlib.mobject.geometry import Line
+from manimlib.utils.bezier import interpolate
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.space_ops import get_norm
 from manimlib.utils.space_ops import z_to_vector
@@ -14,9 +17,9 @@ from manimlib.utils.space_ops import compass_directions
 
 class SurfaceMesh(VGroup):
     CONFIG = {
-        "resolution": (21, 21),
+        "resolution": (21, 11),
         "stroke_width": 1,
-        "normal_nudge": 1e-3,
+        "normal_nudge": 1e-2,
         "depth_test": True,
         "flat_stroke": False,
     }
@@ -32,8 +35,11 @@ class SurfaceMesh(VGroup):
 
         full_nu, full_nv = uv_surface.resolution
         part_nu, part_nv = self.resolution
-        u_indices = np.linspace(0, full_nu, part_nu).astype(int)
-        v_indices = np.linspace(0, full_nv, part_nv).astype(int)
+        # 'indices' are treated as floats. Later, there will be
+        # an interpolation between the floor and ceiling of these
+        # indices
+        u_indices = np.linspace(0, full_nu - 1, part_nu)
+        v_indices = np.linspace(0, full_nv - 1, part_nv)
 
         points, du_points, dv_points = uv_surface.get_surface_points_and_nudged_points()
         normals = uv_surface.get_unit_normals()
@@ -42,12 +48,21 @@ class SurfaceMesh(VGroup):
 
         for ui in u_indices:
             path = VMobject()
-            full_ui = full_nv * ui
-            path.set_points_smoothly(nudged_points[full_ui:full_ui + full_nv])
+            low_ui = full_nv * int(math.floor(ui))
+            high_ui = full_nv * int(math.ceil(ui))
+            path.set_points_smoothly(interpolate(
+                nudged_points[low_ui:low_ui + full_nv],
+                nudged_points[high_ui:high_ui + full_nv],
+                ui % 1
+            ))
             self.add(path)
         for vi in v_indices:
             path = VMobject()
-            path.set_points_smoothly(nudged_points[vi::full_nv])
+            path.set_points_smoothly(interpolate(
+                nudged_points[int(math.floor(vi))::full_nv],
+                nudged_points[int(math.ceil(vi))::full_nv],
+                vi % 1
+            ))
             self.add(path)
 
 
@@ -208,6 +223,53 @@ class VCube(VGroup):
         self.refresh_unit_normal()
 
 
+class Dodecahedron(VGroup):
+    CONFIG = {
+        "fill_color": BLUE_E,
+        "fill_opacity": 1,
+        "stroke_width": 1,
+        "reflectiveness": 0.2,
+        "gloss": 0.3,
+        "shadow": 0.2,
+        "depth_test": True,
+    }
+
+    def init_points(self):
+        # Star by creating two of the pentagons, meeting
+        # back to back on the positive x-axis
+        phi = (1 + math.sqrt(5)) / 2
+        x, y, z = np.identity(3)
+        pentagon1 = Polygon(
+            [phi, 1 / phi, 0],
+            [1, 1, 1],
+            [1 / phi, 0, phi],
+            [1, -1, 1],
+            [phi, -1 / phi, 0],
+        )
+        pentagon2 = pentagon1.copy().stretch(-1, 2, about_point=ORIGIN)
+        pentagon2.reverse_points()
+        x_pair = VGroup(pentagon1, pentagon2)
+        z_pair = x_pair.copy().apply_matrix(np.array([z, -x, -y]).T)
+        y_pair = x_pair.copy().apply_matrix(np.array([y, z, x]).T)
+
+        self.add(*x_pair, *y_pair, *z_pair)
+        for pentagon in list(self):
+            pc = pentagon.copy()
+            pc.apply_function(lambda p: -p)
+            pc.reverse_points()
+            self.add(pc)
+
+        # # Rotate those two pentagons by all the axis permuations to fill
+        # # out the dodecahedron
+        # Id = np.identity(3)
+        # for i in range(3):
+        #     perm = [j % 3 for j in range(i, i + 3)]
+        #     for b in [1, -1]:
+        #         matrix = b * np.array([Id[0][perm], Id[1][perm], Id[2][perm]])
+        #         self.add(pentagon1.copy().apply_matrix(matrix, about_point=ORIGIN))
+        #         self.add(pentagon2.copy().apply_matrix(matrix, about_point=ORIGIN))
+
+
 class Prism(Cube):
     CONFIG = {
         "dimensions": [3, 2, 1]

manimlib/mobject/types/dot_cloud.py

@@ -2,12 +2,14 @@ import numpy as np
 import moderngl
 
 from manimlib.constants import GREY_C
+from manimlib.constants import YELLOW
 from manimlib.constants import ORIGIN
 from manimlib.mobject.types.point_cloud_mobject import PMobject
 from manimlib.utils.iterables import resize_preserving_order
 
 
 DEFAULT_DOT_RADIUS = 0.05
+DEFAULT_GLOW_DOT_RADIUS = 0.2
 DEFAULT_GRID_HEIGHT = 6
 DEFAULT_BUFF_RATIO = 0.5
 
@@ -17,6 +19,7 @@ class DotCloud(PMobject):
         "color": GREY_C,
         "opacity": 1,
         "radius": DEFAULT_DOT_RADIUS,
+        "glow_factor": 0,
         "shader_folder": "true_dot",
         "render_primitive": moderngl.POINTS,
         "shader_dtype": [
@@ -36,6 +39,10 @@ class DotCloud(PMobject):
         self.data["radii"] = np.zeros((1, 1))
         self.set_radius(self.radius)
 
+    def init_uniforms(self):
+        super().init_uniforms()
+        self.uniforms["glow_factor"] = self.glow_factor
+
     def to_grid(self, n_rows, n_cols, n_layers=1,
                 buff_ratio=None,
                 h_buff_ratio=1.0,
@@ -85,6 +92,12 @@ class DotCloud(PMobject):
     def get_radius(self):
         return self.get_radii().max()
 
+    def set_glow_factor(self, glow_factor):
+        self.uniforms["glow_factor"] = glow_factor
+
+    def get_glow_factor(self):
+        return self.uniforms["glow_factor"]
+
     def compute_bounding_box(self):
         bb = super().compute_bounding_box()
         radius = self.get_radius()
@@ -98,8 +111,8 @@ class DotCloud(PMobject):
             self.set_radii(scale_factor * self.get_radii())
         return self
 
-    def make_3d(self, gloss=0.5, shadow=0.2):
-        self.set_gloss(gloss)
+    def make_3d(self, reflectiveness=0.5, shadow=0.2):
+        self.set_reflectiveness(reflectiveness)
         self.set_shadow(shadow)
         self.apply_depth_test()
         return self
@@ -112,5 +125,13 @@ class DotCloud(PMobject):
 
 
 class TrueDot(DotCloud):
-    def __init__(self, center=ORIGIN, radius=DEFAULT_DOT_RADIUS, **kwargs):
-        super().__init__(points=[center], radius=radius, **kwargs)
+    def __init__(self, center=ORIGIN, **kwargs):
+        super().__init__(points=[center], **kwargs)
+
+
+class GlowDot(TrueDot):
+    CONFIG = {
+        "glow_factor": 2,
+        "radius": DEFAULT_GLOW_DOT_RADIUS,
+        "color": YELLOW,
+    }

manimlib/mobject/types/surface.py

@@ -20,7 +20,8 @@ class Surface(Mobject):
         "resolution": (101, 101),
         "color": GREY,
         "opacity": 1.0,
-        "gloss": 0.3,
+        "reflectiveness": 0.3,
+        "gloss": 0.1,
         "shadow": 0.4,
         "prefered_creation_axis": 1,
         # For du and dv steps.  Much smaller and numerical error
@@ -161,6 +162,11 @@ class Surface(Mobject):
             tri_is[k::3] = tri_is[k::3][indices]
         return self
 
+    def always_sort_to_camera(self, camera):
+        self.add_updater(lambda m: m.sort_faces_back_to_front(
+            camera.get_location() - self.get_center()
+        ))
+
     # For shaders
     def get_shader_data(self):
         s_points, du_points, dv_points = self.get_surface_points_and_nudged_points()

manimlib/mobject/types/vectorized_mobject.py

@@ -12,6 +12,7 @@ from manimlib.utils.bezier import get_smooth_quadratic_bezier_handle_points
 from manimlib.utils.bezier import get_smooth_cubic_bezier_handle_points
 from manimlib.utils.bezier import get_quadratic_approximation_of_cubic
 from manimlib.utils.bezier import interpolate
+from manimlib.utils.bezier import inverse_interpolate
 from manimlib.utils.bezier import integer_interpolate
 from manimlib.utils.bezier import partial_quadratic_bezier_points
 from manimlib.utils.color import rgb_to_hex
@@ -74,7 +75,6 @@ class VMobject(Mobject):
         self.needs_new_triangulation = True
         self.triangulation = np.zeros(0, dtype='i4')
         super().__init__(**kwargs)
-        self.refresh_unit_normal()
 
     def get_group_class(self):
         return VGroup
@@ -135,6 +135,10 @@ class VMobject(Mobject):
                 mob.draw_stroke_behind_fill = background
         return self
 
+    def set_backstroke(self, color=BLACK, width=3, background=True):
+        self.set_stroke(color, width, background=background)
+        return self
+
     def align_stroke_width_data_to_points(self, recurse=True):
         for mob in self.get_family(recurse):
             mob.data["stroke_width"] = resize_with_interpolation(
@@ -150,6 +154,7 @@ class VMobject(Mobject):
                   stroke_rgba=None,
                   stroke_width=None,
                   stroke_background=True,
+                  reflectiveness=None,
                   gloss=None,
                   shadow=None,
                   recurse=True):
@@ -177,6 +182,8 @@ class VMobject(Mobject):
                 background=stroke_background,
             )
 
+        if reflectiveness is not None:
+            self.set_reflectiveness(reflectiveness, recurse=recurse)
         if gloss is not None:
             self.set_gloss(gloss, recurse=recurse)
         if shadow is not None:
@@ -185,10 +192,11 @@ class VMobject(Mobject):
 
     def get_style(self):
         return {
-            "fill_rgba": self.data['fill_rgba'],
-            "stroke_rgba": self.data['stroke_rgba'],
-            "stroke_width": self.data['stroke_width'],
+            "fill_rgba": self.data['fill_rgba'].copy(),
+            "stroke_rgba": self.data['stroke_rgba'].copy(),
+            "stroke_width": self.data['stroke_width'].copy(),
             "stroke_background": self.draw_stroke_behind_fill,
+            "reflectiveness": self.get_reflectiveness(),
             "gloss": self.get_gloss(),
             "shadow": self.get_shadow(),
         }
@@ -218,16 +226,17 @@ class VMobject(Mobject):
         return self
 
     def fade(self, darkness=0.5, recurse=True):
-        factor = 1.0 - darkness
-        self.set_fill(
-            opacity=factor * self.get_fill_opacity(),
-            recurse=False,
-        )
-        self.set_stroke(
-            opacity=factor * self.get_stroke_opacity(),
-            recurse=False,
-        )
-        super().fade(darkness, recurse)
+        mobs = self.get_family() if recurse else [self]
+        for mob in mobs:
+            factor = 1.0 - darkness
+            mob.set_fill(
+                opacity=factor * mob.get_fill_opacity(),
+                recurse=False,
+            )
+            mob.set_stroke(
+                opacity=factor * mob.get_stroke_opacity(),
+                recurse=False,
+            )
         return self
 
     def get_fill_colors(self):
@@ -277,9 +286,9 @@ class VMobject(Mobject):
         return self.get_stroke_opacities()[0]
 
     def get_color(self):
-        if self.has_stroke():
-            return self.get_stroke_color()
-        return self.get_fill_color()
+        if self.has_fill():
+            return self.get_fill_color()
+        return self.get_stroke_color()
 
     def has_stroke(self):
         return self.get_stroke_widths().any() and self.get_stroke_opacities().any()
@@ -504,10 +513,10 @@ class VMobject(Mobject):
         nppc = self.n_points_per_curve
         remainder = len(points) % nppc
         points = points[:len(points) - remainder]
-        return [
+        return (
             points[i:i + nppc]
             for i in range(0, len(points), nppc)
-        ]
+        )
 
     def get_bezier_tuples(self):
         return self.get_bezier_tuples_from_points(self.get_points())
@@ -543,12 +552,35 @@ class VMobject(Mobject):
     def get_num_curves(self):
         return self.get_num_points() // self.n_points_per_curve
 
-    def point_from_proportion(self, alpha):
+    def quick_point_from_proportion(self, alpha):
+        # Assumes all curves have the same length, so is inaccurate
         num_curves = self.get_num_curves()
         n, residue = integer_interpolate(0, num_curves, alpha)
         curve_func = self.get_nth_curve_function(n)
         return curve_func(residue)
 
+    def point_from_proportion(self, alpha):
+        if alpha <= 0:
+            return self.get_start()
+        elif alpha >= 1:
+            return self.get_end()
+
+        partials = [0]
+        for tup in self.get_bezier_tuples():
+            # Approximate length with straight line from start to end
+            arclen = get_norm(tup[0] - tup[-1])
+            partials.append(partials[-1] + arclen)
+        full = partials[-1]
+        if full == 0:
+            return self.get_start()
+        # First index where the partial lenth is more alpha times the full length
+        i = next(
+            (i for i, x in enumerate(partials) if x >= full * alpha),
+            len(partials)  # Default
+        )
+        residue = inverse_interpolate(partials[i - 1] / full, partials[i] / full, alpha)
+        return self.get_nth_curve_function(i - 1)(residue)
+
     def get_anchors_and_handles(self):
         """
         returns anchors1, handles, anchors2,
@@ -629,17 +661,19 @@ class VMobject(Mobject):
         area_vect = self.get_area_vector()
         area = get_norm(area_vect)
         if area > 0:
-            return area_vect / area
+            normal = area_vect / area
         else:
             points = self.get_points()
-            return get_unit_normal(
+            normal = get_unit_normal(
                 points[1] - points[0],
                 points[2] - points[1],
             )
+        self.data["unit_normal"][:] = normal
+        return normal
 
     def refresh_unit_normal(self):
         for mob in self.get_family():
-            mob.data["unit_normal"][:] = mob.get_unit_normal(recompute=True)
+            mob.get_unit_normal(recompute=True)
         return self
 
     # Alignment
@@ -701,7 +735,7 @@ class VMobject(Mobject):
         if len(points) == 1:
             return np.repeat(points, nppc * n, 0)
 
-        bezier_groups = self.get_bezier_tuples_from_points(points)
+        bezier_groups = list(self.get_bezier_tuples_from_points(points))
         norms = np.array([
             get_norm(bg[nppc - 1] - bg[0])
             for bg in bezier_groups
@@ -797,7 +831,7 @@ class VMobject(Mobject):
         # how to send the points as to the vertex shader.
         # First triangles come directly from the points
         if normal_vector is None:
-            normal_vector = self.get_unit_normal()
+            normal_vector = self.get_unit_normal(recompute=True)
 
         if not self.needs_new_triangulation:
             return self.triangulation
@@ -853,7 +887,7 @@ class VMobject(Mobject):
     def triggers_refreshed_triangulation(func):
         @wraps(func)
         def wrapper(self, *args, **kwargs):
-            old_points = self.get_points()
+            old_points = self.get_points().copy()
             func(self, *args, **kwargs)
             if not np.all(self.get_points() == old_points):
                 self.refresh_unit_normal()
@@ -999,6 +1033,10 @@ class VGroup(VMobject):
         super().__init__(**kwargs)
         self.add(*vmobjects)
 
+    def __add__(self: 'VGroup', other: 'VMobject' or 'VGroup'):
+        assert(isinstance(other, VMobject))
+        return self.add(other)
+
 
 class VectorizedPoint(Point, VMobject):
     CONFIG = {
@@ -1010,7 +1048,8 @@ class VectorizedPoint(Point, VMobject):
     }
 
     def __init__(self, location=ORIGIN, **kwargs):
-        super().__init__(**kwargs)
+        Point.__init__(self, **kwargs)
+        VMobject.__init__(self, **kwargs)
         self.set_points(np.array([location]))
 
 

manimlib/scene/scene.py

@@ -56,6 +56,8 @@ class Scene(object):
         self.time = 0
         self.skip_time = 0
         self.original_skipping_status = self.skip_animations
+        if self.start_at_animation_number is not None:
+            self.skip_animations = True
 
         # Items associated with interaction
         self.mouse_point = Point()
@@ -135,7 +137,7 @@ class Scene(object):
         for term in ("play", "wait", "add", "remove", "clear", "save_state", "restore"):
             local_ns[term] = getattr(self, term)
         log.info("Tips: Now the embed iPython terminal is open. But you can't interact with"
-            " the window directly. To do so, you need to type `touch()` or `self.interact()`")
+                 " the window directly. To do so, you need to type `touch()` or `self.interact()`")
         shell(local_ns=local_ns, stack_depth=2)
         # End scene when exiting an embed.
         raise EndSceneEarlyException()
@@ -184,6 +186,13 @@ class Scene(object):
             for mob in self.mobjects
         ])
 
+    def has_time_based_updaters(self):
+        return any([
+            sm.has_time_based_updater()
+            for mob in self.mobjects()
+            for sm in mob.get_family()
+        ])
+
     # Related to time
     def get_time(self):
         return self.time
@@ -271,59 +280,54 @@ class Scene(object):
     def update_skipping_status(self):
         if self.start_at_animation_number is not None:
             if self.num_plays == self.start_at_animation_number:
-                self.stop_skipping()
+                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 EndSceneEarlyException()
 
     def stop_skipping(self):
-        if self.skip_animations:
-            self.skip_animations = False
-            self.skip_time += self.time
+        self.virtual_animation_start_time = self.time
+        self.skip_animations = False
 
     # Methods associated with running animations
-    def get_time_progression(self, run_time, n_iterations=None, override_skip_animations=False):
+    def get_time_progression(self, run_time, n_iterations=None, desc="", override_skip_animations=False):
         if self.skip_animations and not override_skip_animations:
-            times = [run_time]
+            return [run_time]
         else:
             step = 1 / self.camera.frame_rate
             times = np.arange(0, run_time, step)
-        time_progression = ProgressDisplay(
+
+        if self.file_writer.has_progress_display:
+            self.file_writer.set_progress_display_subdescription(desc)
+            return times
+
+        return ProgressDisplay(
             times,
             total=n_iterations,
             leave=self.leave_progress_bars,
-            ascii=True if platform.system() == 'Windows' else None
+            ascii=True if platform.system() == 'Windows' else None,
+            desc=desc,
         )
-        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 = self.get_run_time(animations)
-        time_progression = self.get_time_progression(run_time)
-        time_progression.set_description("".join([
-            f"Animation {self.num_plays}: {animations[0]}",
-            ", etc." if len(animations) > 1 else "",
-        ]))
+        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, stop_condition):
+    def get_wait_time_progression(self, duration, stop_condition=None):
+        kw = {"desc": f"{self.num_plays} Waiting"}
         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
+            kw["n_iterations"] = -1  # So it doesn't show % progress
+            kw["override_skip_animations"] = True
+        return self.get_time_progression(duration, **kw)
 
     def anims_from_play_args(self, *args, **kwargs):
         """
@@ -475,27 +479,18 @@ class Scene(object):
     @handle_play_like_call
     def wait(self, duration=DEFAULT_WAIT_TIME, stop_condition=None):
         self.update_mobjects(dt=0)  # Any problems with this?
-        if self.should_update_mobjects():
-            self.lock_static_mobject_data()
-            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():
-                    time_progression.close()
-                    break
-            self.unlock_mobject_data()
-        elif self.skip_animations:
-            # Do nothing
-            return self
-        else:
-            self.update_frame(duration)
-            n_frames = int(duration * self.camera.frame_rate)
-            for n in range(n_frames):
-                self.emit_frame()
+        self.lock_static_mobject_data()
+        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():
+                time_progression.close()
+                break
+        self.unlock_mobject_data()
         return self
 
     def wait_until(self, stop_condition, max_time=60):

manimlib/scene/scene_file_writer.py

@@ -5,6 +5,7 @@ import subprocess as sp
 import os
 import sys
 import platform
+from tqdm import tqdm as ProgressDisplay
 
 from manimlib.constants import FFMPEG_BIN
 from manimlib.utils.config_ops import digest_config
@@ -35,12 +36,15 @@ class SceneFileWriter(object):
         "open_file_upon_completion": False,
         "show_file_location_upon_completion": False,
         "quiet": False,
+        "total_frames": 0,
+        "progress_description_len": 60,
     }
 
     def __init__(self, scene, **kwargs):
         digest_config(self, kwargs)
         self.scene = scene
         self.writing_process = None
+        self.has_progress_display = False
         self.init_output_directories()
         self.init_audio()
 
@@ -72,10 +76,14 @@ class SceneFileWriter(object):
         return path
 
     def get_default_scene_name(self):
-        if self.file_name is None:
-            return self.scene.__class__.__name__
-        else:
-            return self.file_name
+        name = str(self.scene)
+        saan = self.scene.start_at_animation_number
+        eaan = self.scene.end_at_animation_number
+        if saan is not None:
+            name += f"_{saan}"
+        if eaan is not None:
+            name += f"_{eaan}"
+        return name
 
     def get_resolution_directory(self):
         pixel_height = self.scene.camera.pixel_height
@@ -205,15 +213,39 @@ class SceneFileWriter(object):
         command += [self.temp_file_path]
         self.writing_process = sp.Popen(command, stdin=sp.PIPE)
 
+        if self.total_frames > 0:
+            self.progress_display = ProgressDisplay(
+                range(self.total_frames),
+                # bar_format="{l_bar}{bar}|{n_fmt}/{total_fmt}",
+                leave=False,
+                ascii=True if platform.system() == 'Windows' else None,
+                dynamic_ncols=True,
+            )
+            self.has_progress_display = True
+
+    def set_progress_display_subdescription(self, sub_desc):
+        desc_len = self.progress_description_len
+        file = os.path.split(self.get_movie_file_path())[1]
+        full_desc = f"Rendering {file} ({sub_desc})"
+        if len(full_desc) > desc_len:
+            full_desc = full_desc[:desc_len - 4] + "...)"
+        else:
+            full_desc += " " * (desc_len - len(full_desc))
+        self.progress_display.set_description(full_desc)
+
     def write_frame(self, camera):
         if self.write_to_movie:
             raw_bytes = camera.get_raw_fbo_data()
             self.writing_process.stdin.write(raw_bytes)
+            if self.has_progress_display:
+                self.progress_display.update()
 
     def close_movie_pipe(self):
         self.writing_process.stdin.close()
         self.writing_process.wait()
         self.writing_process.terminate()
+        if self.has_progress_display:
+            self.progress_display.close()
         shutil.move(self.temp_file_path, self.final_file_path)
 
     def combine_movie_files(self):
@@ -301,7 +333,8 @@ class SceneFileWriter(object):
         self.print_file_ready_message(file_path)
 
     def print_file_ready_message(self, file_path):
-        log.info(f"File ready at {file_path}")
+        if not self.quiet:
+            log.info(f"File ready at {file_path}")
 
     def should_open_file(self):
         return any([

manimlib/scene/three_d_scene.py

@@ -5,7 +5,6 @@ class ThreeDScene(Scene):
     CONFIG = {
         "camera_config": {
             "samples": 4,
-            "anti_alias_width": 0,
         }
     }
 

manimlib/shaders/inserts/camera_uniform_declarations.glsl

@@ -1,6 +1,6 @@
 uniform vec2 frame_shape;
 uniform float anti_alias_width;
-uniform vec3 camera_center;
+uniform vec3 camera_offset;
 uniform mat3 camera_rotation;
 uniform float is_fixed_in_frame;
 uniform float focal_distance;

manimlib/shaders/inserts/finalize_color.glsl

@@ -13,39 +13,56 @@ vec4 add_light(vec4 color,
                vec3 point,
                vec3 unit_normal,
                vec3 light_coords,
+               vec3 cam_coords,
+               float reflectiveness,
                float gloss,
                float shadow){
-    if(gloss == 0.0 && shadow == 0.0) return color;
+    if(reflectiveness == 0.0 && gloss == 0.0 && shadow == 0.0) return color;
 
-    float camera_distance = focal_distance;
+    vec4 result = color;
     // Assume everything has already been rotated such that camera is in the z-direction
-    vec3 to_camera = vec3(0, 0, camera_distance) - point;
-    vec3 to_light = light_coords - point;
+    // cam_coords = vec3(0, 0, focal_distance);
+    vec3 to_camera = normalize(cam_coords - point);
+    vec3 to_light = normalize(light_coords - point);
 
-    // TODO, do we actually want this?  It effectively treats surfaces as two-sided
-    if(dot(to_camera,unit_normal) < 0){
-            unit_normal *= -1;
-    }
+    // Note, this effectively treats surfaces as two-sided
+    // if(dot(to_camera, unit_normal) < 0) unit_normal *= -1;
 
+    float light_to_normal = dot(to_light, unit_normal);
+    // When unit normal points towards light, brighten
+    float bright_factor = max(light_to_normal, 0) * reflectiveness;
+    // For glossy surface, add extra shine if light beam go towards camera
     vec3 light_reflection = -to_light + 2 * unit_normal * dot(to_light, unit_normal);
-    float dot_prod = dot(normalize(light_reflection), normalize(to_camera));
-    float shine = gloss * exp(-3 * pow(1 - dot_prod, 2));
-    float dp2 = dot(normalize(to_light), unit_normal);
-    float darkening = mix(1, max(dp2, 0), shadow);
-    return vec4(
-            darkening * mix(color.rgb, vec3(1.0), shine),
-            color.a
-    );
+    float light_to_cam = dot(light_reflection, to_camera);
+    float shine = gloss * exp(-3 * pow(1 - light_to_cam, 2));
+    bright_factor += shine;
+
+    result.rgb = mix(result.rgb, vec3(1.0), bright_factor);
+    if (light_to_normal < 0){
+        // Darken
+        result.rgb = mix(result.rgb, vec3(0.0), -light_to_normal * shadow);
+    }
+    // float darkening = mix(1, max(light_to_normal, 0), shadow);
+    // return vec4(
+    //     darkening * mix(color.rgb, vec3(1.0), shine),
+    //     color.a
+    // );
+    return result;
 }
 
 vec4 finalize_color(vec4 color,
                     vec3 point,
                     vec3 unit_normal,
                     vec3 light_coords,
+                    vec3 cam_coords,
+                    float reflectiveness,
                     float gloss,
                     float shadow){
     ///// INSERT COLOR FUNCTION HERE /////
     // The line above may be replaced by arbitrary code snippets, as per
     // the method Mobject.set_color_by_code
-    return add_light(color, point, unit_normal, light_coords, gloss, shadow);
+    return add_light(
+        color, point, unit_normal, light_coords, cam_coords,
+        reflectiveness, gloss, shadow
+    );
 }

manimlib/shaders/inserts/get_rotated_surface_unit_normal_vector.glsl

@@ -1,5 +1,5 @@
 // Assumes the following uniforms exist in the surrounding context:
-// uniform vec3 camera_center;
+// uniform vec3 camera_offset;
 // uniform mat3 camera_rotation;
 
 vec3 get_rotated_surface_unit_normal_vector(vec3 point, vec3 du_point, vec3 dv_point){

manimlib/shaders/inserts/position_point_into_frame.glsl

@@ -1,6 +1,6 @@
 // Assumes the following uniforms exist in the surrounding context:
 // uniform float is_fixed_in_frame;
-// uniform vec3 camera_center;
+// uniform vec3 camera_offset;
 // uniform mat3 camera_rotation;
 
 vec3 rotate_point_into_frame(vec3 point){
@@ -15,5 +15,5 @@ vec3 position_point_into_frame(vec3 point){
     if(bool(is_fixed_in_frame)){
         return point;
     }
-    return rotate_point_into_frame(point - camera_center);
+    return rotate_point_into_frame(point - camera_offset);
 }

manimlib/shaders/mandelbrot_fractal/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -71,6 +73,8 @@ void main() {
         xyz_coords,
         vec3(0.0, 0.0, 1.0),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/newton_fractal/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -75,7 +77,7 @@ vec2 seek_root(vec2 z, vec2[MAX_DEGREE + 1] coefs, int max_steps, out float n_it
         }
         z = z - step;
     }
-    n_iters -= clamp((threshold - curr_len) / (last_len - curr_len), 0.0, 1.0);
+    n_iters -= log(curr_len) / log(threshold);
 
     return z;
 }
@@ -118,7 +120,7 @@ void main() {
             color = colors[i];
         }
     }
-    color *= 1.0 + (0.01 * saturation_factor) * (n_iters - 5 * saturation_factor);
+    color *= 1.0 + (0.01 * saturation_factor) * (n_iters - 2 * saturation_factor);
 
     if(black_for_cycles > 0 && min_dist > CLOSE_ENOUGH){
         color = vec4(0.0, 0.0, 0.0, 1.0);
@@ -151,6 +153,8 @@ void main() {
         xyz_coords,
         vec3(0.0, 0.0, 1.0),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/quadratic_bezier_fill/frag.glsl

@@ -3,7 +3,7 @@
 #INSERT camera_uniform_declarations.glsl
 
 in vec4 color;
-in float fill_all;  // Either 0 or 1e
+in float fill_all;  // Either 0 or 1
 in float uv_anti_alias_width;
 
 in vec3 xyz_coords;

manimlib/shaders/quadratic_bezier_fill/geom.glsl

@@ -11,6 +11,8 @@ uniform float focal_distance;
 uniform float is_fixed_in_frame;
 // Needed for finalize_color
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 
@@ -44,6 +46,8 @@ void emit_vertex_wrapper(vec3 point, int index){
         point,
         v_global_unit_normal[index],
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/quadratic_bezier_stroke/geom.glsl

@@ -13,7 +13,9 @@ uniform float flat_stroke;
 
 //Needed for lighting
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
 uniform float joint_type;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 
@@ -259,6 +261,8 @@ void main() {
             xyz_coords,
             v_global_unit_normal[index_map[i]],
             light_source_position,
+            camera_position,
+            reflectiveness,
             gloss,
             shadow
         );

manimlib/shaders/surface/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -19,6 +21,8 @@ void main() {
         xyz_coords,
         normalize(v_normal),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/textured_surface/frag.glsl

@@ -4,6 +4,8 @@ uniform sampler2D LightTexture;
 uniform sampler2D DarkTexture;
 uniform float num_textures;
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -36,6 +38,8 @@ void main() {
         xyz_coords,
         normalize(v_normal),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/true_dot/frag.glsl

@@ -1,10 +1,13 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float anti_alias_width;
 uniform float focal_distance;
+uniform float glow_factor;
 
 in vec4 color;
 in float radius;
@@ -22,14 +25,23 @@ void main() {
     if (signed_dist > 0.5 * anti_alias_width){
         discard;
     }
-    vec3 normal = vec3(diff / radius, sqrt(1 - (dist * dist) / (radius * radius)));
-    frag_color = finalize_color(
-        color,
-        vec3(point.xy, 0.0),
-        normal,
-        light_source_position,
-        gloss,
-        shadow
-    );
+    frag_color = color;
+    if(gloss > 0 || shadow > 0){
+        vec3 normal = vec3(diff / radius, sqrt(1 - (dist * dist) / (radius * radius)));
+        frag_color = finalize_color(
+            frag_color,
+            vec3(point.xy, 0.0),
+            normal,
+            light_source_position,
+            camera_position,
+            reflectiveness,
+            gloss,
+            shadow
+        );
+    }
+    if(glow_factor > 0){
+        frag_color.a *= pow(1 - dist / radius, glow_factor);
+    }
+
     frag_color.a *= smoothstep(0.5, -0.5, signed_dist / anti_alias_width);
 }

manimlib/utils/space_ops.py

@@ -10,6 +10,15 @@ from manimlib.constants import OUT
 from manimlib.constants import PI
 from manimlib.constants import TAU
 from manimlib.utils.iterables import adjacent_pairs
+from manimlib.utils.simple_functions import clip
+
+
+def cross(v1, v2):
+    return [
+        v1[1] * v2[2] - v1[2] * v2[1],
+        v1[2] * v2[0] - v1[0] * v2[2],
+        v1[0] * v2[1] - v1[1] * v2[0]
+    ]
 
 
 def get_norm(vect):
@@ -147,6 +156,15 @@ def z_to_vector(vector):
     return rotation_matrix(angle, axis=axis)
 
 
+def rotation_between_vectors(v1, v2):
+    if np.all(np.isclose(v1, v2)):
+        return np.identity(3)
+    return rotation_matrix(
+        angle=angle_between_vectors(v1, v2),
+        axis=normalize(np.cross(v1, v2))
+    )
+
+
 def angle_of_vector(vector):
     """
     Returns polar coordinate theta when vector is project on xy plane
@@ -159,8 +177,7 @@ def angle_between_vectors(v1, v2):
     Returns the angle between two 3D vectors.
     This angle will always be btw 0 and pi
     """
-    diff = (angle_of_vector(v2) - angle_of_vector(v1)) % TAU
-    return min(diff, TAU - diff)
+    return math.acos(clip(np.dot(normalize(v1), normalize(v2)), -1, 1))
 
 
 def project_along_vector(point, vector):
@@ -186,14 +203,6 @@ def normalize_along_axis(array, axis, fall_back=None):
     return array
 
 
-def cross(v1, v2):
-    return np.array([
-        v1[1] * v2[2] - v1[2] * v2[1],
-        v1[2] * v2[0] - v1[0] * v2[2],
-        v1[0] * v2[1] - v1[1] * v2[0]
-    ])
-
-
 def get_unit_normal(v1, v2, tol=1e-6):
     v1 = normalize(v1)
     v2 = normalize(v2)

requirements.txt

@@ -9,6 +9,7 @@ mapbox-earcut
 matplotlib
 moderngl
 moderngl_window
+skia-pathops
 pydub
 pygments
 pyyaml

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = manimgl
-version = 1.2.0
+version = 1.3.0
 author = Grant Sanderson
 author_email= grant@3blue1brown.com
 description = Animation engine for explanatory math videos
@@ -28,6 +28,7 @@ install_requires =
     matplotlib
     moderngl
     moderngl_window
+    skia-pathops
     pydub
     pygments
     pyyaml