Render image automatically if no animation is played in a scene (#1261)

* Display image instead if attempting to make movie file with no animations

* update

* logging warnings added

* small fixes

* Fix broken test, add suggestions

* ignore skipping if scene finished

* fixes + replace self.play(Anim.. with self.add()

* dummy commit

* explicitly set write_to_movie in manim_directive

Co-authored-by: Jason Villanueva <[email protected]>
Co-authored-by: Benjamin Hackl <[email protected]>

Author: 3 people

docs/source/manim_directive.py

@@ -221,6 +221,7 @@ def run(self):
             f'config["pixel_width"] = {pixel_width}',
             f'config["save_last_frame"] = {save_last_frame}',
             f'config["save_as_gif"] = {save_as_gif}',
+            f'config["write_to_movie"] = {not save_last_frame}',
             f'config["output_file"] = r"{output_file}"',
         ]
 

manim/renderer/cairo_renderer.py

@@ -266,7 +266,15 @@ def update_skipping_status(self):
                 raise EndSceneEarlyException()
 
     def scene_finished(self, scene):
-        self.file_writer.finish()
+        # If no animations in scene, render an image instead
+        if self.num_plays:
+            self.file_writer.finish()
+        elif config.write_to_movie:
+            config.save_last_frame = True
+            config.write_to_movie = False
+        else:
+            self.update_frame(scene)
+
         if config["save_last_frame"]:
-            self.update_frame(scene, ignore_skipping=False)
+            self.update_frame(scene)
             self.file_writer.save_final_image(self.camera.get_image())

manim/scene/scene.py

@@ -187,9 +187,11 @@ def render(self, preview=False):
         # We have to reset these settings in case of multiple renders.
         self.renderer.scene_finished(self)
 
-        logger.info(
-            f"Rendered {str(self)}\nPlayed {self.renderer.num_plays} animations"
-        )
+        # Show info only if animations are rendered or to get image
+        if self.renderer.num_plays or config["save_last_frame"] or config["save_pngs"]:
+            logger.info(
+                f"Rendered {str(self)}\nPlayed {self.renderer.num_plays} animations"
+            )
 
         # If preview open up the render after rendering.
         if preview:

manim/scene/scene_file_writer.py

@@ -78,14 +78,13 @@ def init_output_directories(self, scene_name):
         else:
             default_name = Path(scene_name)
 
-        if config["save_last_frame"] or config["save_pngs"]:
-            if config["media_dir"]:
-                image_dir = guarantee_existence(
-                    config.get_dir("images_dir", module_name=module_name)
-                )
-            self.image_file_path = os.path.join(
-                image_dir, add_extension_if_not_present(default_name, ".png")
+        if config["media_dir"]:
+            image_dir = guarantee_existence(
+                config.get_dir("images_dir", module_name=module_name)
             )
+        self.image_file_path = os.path.join(
+            image_dir, add_extension_if_not_present(default_name, ".png")
+        )
 
         if config["write_to_movie"]:
             movie_dir = guarantee_existence(

tests/control_data/graphical_units_data/updaters/ValueTrackerTest.npz

@@ -17,7 +17,7 @@ def construct(self):
             y_axis_config={"x_max": 5, "width": 6, "label_direction": UL},
             center_point=2 * DL,
         )
-        self.play(Animation(plane))
+        self.add(plane)
 
 
 MODULE_NAME = "coordinate_systems"

tests/test_graphical_units/test_coordinate_systems.py

@@ -13,7 +13,6 @@ def construct(self):
             lambda x: 2 * np.cos(0.5 * x), x_min=-PI, x_max=PI, color=BLUE
         )
         self.add(graph)
-        self.wait()
 
 
 MODULE_NAME = "functions"

tests/test_graphical_units/test_functions.py

@@ -9,25 +9,25 @@
 class CoordinatesTest(Scene):
     def construct(self):
         dots = [Dot(np.array([x, y, 0])) for x in range(-7, 8) for y in range(-4, 5)]
-        self.play(Animation(VGroup(*dots)))
+        self.add(VGroup(*dots))
 
 
 class ArcTest(Scene):
     def construct(self):
         a = Arc(PI)
-        self.play(Animation(a))
+        self.add(a)
 
 
 class ArcBetweenPointsTest(Scene):
     def construct(self):
         a = ArcBetweenPoints(np.array([1, 1, 0]), np.array([2, 2, 0]))
-        self.play(Animation(a))
+        self.add(a)
 
 
 class CurvedArrowTest(Scene):
     def construct(self):
         a = CurvedArrow(np.array([1, 1, 0]), np.array([2, 2, 0]))
-        self.play(Animation(a))
+        self.add(a)
 
 
 class CustomDoubleArrowTest(Scene):
@@ -40,91 +40,91 @@ def construct(self):
             tip_shape_start=ArrowCircleTip,
             tip_shape_end=ArrowSquareFilledTip,
         )
-        self.play(Animation(a))
+        self.add(a)
 
 
 class CircleTest(Scene):
     def construct(self):
         circle = Circle()
-        self.play(Animation(circle))
+        self.add(circle)
 
 
 class DotTest(Scene):
     def construct(self):
         dot = Dot()
-        self.play(Animation(dot))
+        self.add(dot)
 
 
 class AnnotationDotTest(Scene):
     def construct(self):
         adot = AnnotationDot()
-        self.play(Animation(adot))
+        self.add(adot)
 
 
 class EllipseTest(Scene):
     def construct(self):
         e = Ellipse()
-        self.play(Animation(e))
+        self.add(e)
 
 
 class SectorTest(Scene):
     def construct(self):
         e = Sector()
-        self.play(Animation(e))
+        self.add(e)
 
 
 class AnnulusTest(Scene):
     def construct(self):
         a = Annulus()
-        self.play(Animation(a))
+        self.add(a)
 
 
 class AnnularSectorTest(Scene):
     def construct(self):
         a = AnnularSector()
-        self.play(Animation(a))
+        self.add(a)
 
 
 class LineTest(Scene):
     def construct(self):
         a = Line(np.array([1, 1, 0]), np.array([2, 2, 0]))
-        self.play(Animation(a))
+        self.add(a)
 
 
 class ElbowTest(Scene):
     def construct(self):
         a = Elbow()
-        self.play(Animation(a))
+        self.add(a)
 
 
 class DoubleArrowTest(Scene):
     def construct(self):
         a = DoubleArrow()
-        self.play(Animation(a))
+        self.add(a)
 
 
 class VectorTest(Scene):
     def construct(self):
         a = Vector(UP)
-        self.play(Animation(a))
+        self.add(a)
 
 
 class PolygonTest(Scene):
     def construct(self):
         a = Polygon(*[np.array([1, 1, 0]), np.array([2, 2, 0]), np.array([2, 3, 0])])
-        self.play(Animation(a))
+        self.add(a)
 
 
 class RectangleTest(Scene):
     def construct(self):
         a = Rectangle()
-        self.play(Animation(a))
+        self.add(a)
 
 
 class RoundedRectangleTest(Scene):
     def construct(self):
         a = RoundedRectangle()
-        self.play(Animation(a))
+        self.add(a)
 
 
 class ArrangeTest(Scene):
@@ -133,7 +133,6 @@ def construct(self):
         s2 = Square()
         x = VGroup(s1, s2).set_x(0).arrange(buff=1.4)
         self.add(x)
-        self.wait()
 
 
 class ZIndexTest(Scene):
@@ -148,23 +147,22 @@ def construct(self):
         self.play(FadeIn(VGroup(circle, square, triangle)))
         self.play(ApplyMethod(circle.shift, UP))
         self.play(ApplyMethod(triangle.shift, 2 * UP))
-        self.wait(1)
 
 
 class AngleTest(Scene):
     def construct(self):
         l1 = Line(ORIGIN, RIGHT)
         l2 = Line(ORIGIN, UP)
         a = Angle(l1, l2)
-        self.play(Animation(a))
+        self.add(a)
 
 
 class RightAngleTest(Scene):
     def construct(self):
         l1 = Line(ORIGIN, RIGHT)
         l2 = Line(ORIGIN, UP)
         a = RightAngle(l1, l2)
-        self.play(Animation(a))
+        self.add(a)
 
 
 MODULE_NAME = "geometry"

tests/test_graphical_units/test_geometry.py

@@ -27,7 +27,7 @@ def construct(self):
         self.setup_axes()
         f = self.get_graph(lambda x: x ** 2)
 
-        self.play(Animation(f))
+        self.add(f)
 
 
 MODULE_NAME = "plot"

tests/test_graphical_units/test_graphscene.py

@@ -9,7 +9,7 @@
 class PointCloudDotTest(ThreeDScene):
     def construct(self):
         p = PointCloudDot()
-        self.play(Animation(p))
+        self.add(p)
 
 
 MODULE_NAME = "mobjects"