Manim¶

Shrimply can put a 3b1b Manim scene on the timeline. The scene renders at the project canvas size and frame rate, with a transparent background.

Manim files need approval before they run. See Security.

Create a scene¶

Shrimply includes its own copy of Manim. Scene files import that copy through manimlib and define at least one Scene subclass:

from manimlib import *


class HelloShrimply(Scene):
    def construct(self):
        square = Square()
        circle = Circle()
        circle.set_fill(BLUE, opacity=0.5)

        self.play(ShowCreation(square))
        self.wait()
        self.play(ReplacementTransform(square, circle))
        self.wait()

The scene’s play and wait calls determine its duration. Shrimply updates the timeline item to that duration after the scene loads. A scene with no play or wait call becomes a single still frame.

Import and edit a scene¶

Import the .py file onto a video track with Import Media…, or drag it onto the timeline. Select the item to open its Manim controls in the inspector.

If the file defines multiple scene classes, choose one with the Scene control. Changing the scene clears parameter values from the previously selected scene. Anti-aliasing smooths edges and takes longer.

After editing the Python source, click the reload button in the Manim inspector to rebuild the scene and refresh its scene list and parameters. Python errors appear in the same inspector.

Expose parameters in the inspector¶

shrimply_manim turns Python values into inspector controls. Each call returns the value set in Shrimply, or the default if it has not been set. Shrimply provides shrimply_manim while loading the scene. It is not part of upstream Manim.

Call the functions inside construct so each scene exposes only its own controls:

from fractions import Fraction

from manimlib import *
from shrimply_manim import use_color, use_fraction, use_float, use_option


class ReflectedScene(Scene):
    def construct(self):
        radius = use_float(
            1.0,
            min=0.25,
            max=3.0,
            step=0.25,
            key="radius",
            label="Radius",
        )
        color = use_color("blue3", key="color", label="Color")
        entrance = use_option(
            ["Draw", "Fade"],
            key="entrance",
            label="Entrance",
        )
        hold = use_fraction(
            Fraction(1, 2),
            key="hold",
            label="Hold time",
        )

        circle = Circle(radius=radius)
        circle.set_fill(color, opacity=0.5)
        if entrance == "Draw":
            self.play(ShowCreation(circle))
        else:
            self.play(FadeIn(circle))
        self.wait(hold)

Available controls¶

Function	Inspector control	Useful options
`use_int(default=0)`	Integer field	`min`, `max`, and positive `step`
`use_float(default=0.0)`	Decimal field	`min`, `max`, and positive `step`
`use_fraction(default=Fraction(0))`	Exact decimal field	Use for durations and other values that should remain exact
`use_color(default="blue3")`	Color picker	A `#RRGGBB` value or an Adwaita color from `blue1` through `blue5`, and likewise for green, yellow, orange, red, purple, brown, light, and dark
`use_option(options, default=None)`	Choice menu	A nonempty sequence of unique strings; the first is the default when `default` is omitted
`use_bool(default=False)`	Switch	`True` or `False`
`use_string(default="")`	Single-line text field	Any string

Every function also accepts keyword-only key and label arguments. label is the name shown in the inspector. key is the stable identity used to save the value in the project.

Parameter guidelines¶

Give every parameter an explicit, unique key. A generated key follows call order, so adding or moving a parameter can attach a saved value to the wrong control.
Keep the calls unconditional and in a stable order, so the inspector stays put when another parameter changes.
Treat a key’s type as fixed. If the type changes, pick a new key or reset the parameter in the inspector.
A parameter at module scope, including one in a sibling module the scene imports, shows up on every scene in the file. Scene-specific values belong in construct.