Change seek_full_path_from_defaults to find_file, and make it a more general function which will find and download urls if needed. This means for images/textures/etc. one can point online

example_scenes.py

@@ -202,17 +202,17 @@ class SurfaceExample(Scene):
         torus1 = Torus(r1=1, r2=1)
         torus2 = Torus(r1=3, r2=1)
         sphere = Sphere(radius=3, resolution=torus1.resolution)
-        surfaces = [sphere, torus1, torus2]
-        # If you want these to be textured with pictures of, say, earth,
-        # find images for the texture maps you want, perhaps
-        # https://en.wikipedia.org/wiki/File:Blue_Marble_2002.png and
-        # https://commons.wikimedia.org/wiki/File:The_earth_at_night.jpg
-        # and make sure they are available in whatever folder manim
-        # looks for images, then uncomment the lines below
-        # surfaces = [
-        #     TexturedSurface(surface, "EarthTextureMap", "NightEarthTextureMap")
-        #     for surface in [sphere, torus1, torus2]
-        # ]
+        # You can texture a surface with up to two images, which will
+        # be interpreted as the side towards the light, and away from
+        # the light.  These can be either urls, or paths to a local file
+        # in whatever you've set as the iamge directory in
+        # the custom_defaults.yml file
+        day_texture = "https://upload.wikimedia.org/wikipedia/commons/thumb/2/23/Blue_Marble_2002.png/1280px-Blue_Marble_2002.png"
+        night_texture = "https://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/The_earth_at_night.jpg/1280px-The_earth_at_night.jpg"
+        surfaces = [
+            TexturedSurface(surface, day_texture, night_texture)
+            for surface in [sphere, torus1, torus2]
+        ]
 
         for mob in surfaces:
             mob.mesh = SurfaceMesh(mob)

manimlib/shader_wrapper.py

@@ -1,12 +1,11 @@
 import os
-import logging
 import re
 import moderngl
 import numpy as np
 import copy
 
 from manimlib.utils.directories import get_shader_dir
-from manimlib.utils.file_ops import seek_full_path_from_defaults
+from manimlib.utils.file_ops import find_file
 
 # Mobjects that should be rendered with
 # the same shader will be organized and
@@ -111,7 +110,7 @@ def get_shader_code_from_file(filename):
         return None
 
     try:
-        filepath = seek_full_path_from_defaults(
+        filepath = find_file(
             filename,
             directories=[get_shader_dir(), "/"],
             extensions=[],

manimlib/utils/directories.py

@@ -25,12 +25,16 @@ def get_directories():
     return PRE_COMPUTED_DIRS
 
 
+def get_temp_dir():
+    return get_directories()["temporary_storage"]
+
+
 def get_tex_dir():
-    return guarantee_existence(os.path.join(get_directories()["temporary_storage"], "Tex"))
+    return guarantee_existence(os.path.join(get_temp_dir(), "Tex"))
 
 
 def get_mobject_data_dir():
-    return guarantee_existence(os.path.join(get_directories()["temporary_storage"], "mobject_data"))
+    return guarantee_existence(os.path.join(get_temp_dir(), "mobject_data"))
 
 
 def get_output_dir():

manimlib/utils/file_ops.py

@@ -1,6 +1,10 @@
 import os
 import numpy as np
 
+import validators
+import urllib.request
+import tempfile
+
 
 def add_extension_if_not_present(file_name, extension):
     # This could conceivably be smarter about handling existing differing extensions
@@ -16,17 +20,34 @@ def guarantee_existence(path):
     return os.path.abspath(path)
 
 
-def seek_full_path_from_defaults(file_name, directories, extensions):
-    possible_paths = [file_name]
-    possible_paths += [
+def find_file(file_name, directories=None, extensions=None):
+    # Check if this is a file online first, and if so, download
+    # it to a temporary directory
+    if validators.url(file_name):
+        stem, name = os.path.split(file_name)
+        folder = guarantee_existence(
+            os.path.join(tempfile.gettempdir(), "manim_downloads")
+        )
+        path = os.path.join(folder, name)
+        urllib.request.urlretrieve(file_name, path)
+        return path
+
+    # Check if what was passed in is already a valid path to a file
+    if os.path.exists(file_name):
+        return file_name
+
+    # Otherwise look in local file system
+    directories = directories or [""]
+    extensions = extensions or [""]
+    possible_paths = (
         os.path.join(directory, file_name + extension)
         for directory in directories
-        for extension in ["", *extensions]
-    ]
+        for extension in extensions
+    )
     for path in possible_paths:
         if os.path.exists(path):
             return path
-    raise IOError("File {} not Found".format(file_name))
+    raise IOError(f"{file_name} not Found")
 
 
 def get_sorted_integer_files(directory,

manimlib/utils/images.py

@@ -1,14 +1,13 @@
 import numpy as np
-
 from PIL import Image
 
-from manimlib.utils.file_ops import seek_full_path_from_defaults
+from manimlib.utils.file_ops import find_file
 from manimlib.utils.directories import get_raster_image_dir
 from manimlib.utils.directories import get_vector_image_dir
 
 
 def get_full_raster_image_path(image_file_name):
-    return seek_full_path_from_defaults(
+    return find_file(
         image_file_name,
         directories=[get_raster_image_dir()],
         extensions=[".jpg", ".png", ".gif"]
@@ -16,7 +15,7 @@ def get_full_raster_image_path(image_file_name):
 
 
 def get_full_vector_image_path(image_file_name):
-    return seek_full_path_from_defaults(
+    return find_file(
         image_file_name,
         directories=[get_vector_image_dir()],
         extensions=[".svg", ".xdv"],

manimlib/utils/sounds.py

@@ -1,5 +1,5 @@
 import os
-from manimlib.utils.file_ops import seek_full_path_from_defaults
+from manimlib.utils.file_ops import find_file
 
 
 def play_chord(*nums):
@@ -32,7 +32,7 @@ def play_finish_sound():
 
 
 def get_full_sound_file_path(sound_file_name):
-    return seek_full_path_from_defaults(
+    return find_file(
         sound_file_name,
         directories=[os.path.join("assets", "sounds")],
         extensions=[".wav", ".mp3"]

requirements.txt

@@ -15,3 +15,5 @@ PyOpenGL
 pyyaml
 screeninfo
 pyreadline; sys_platform == 'win32'
+tempfile
+validators