Quick start

One point moves across the view, and the same animation is written to three formats.

from kinetickit import Animation, Bounds2D, Point2D, Scene2D, Vec2, ease

dot = Point2D(id="dot", position=Vec2(1, 1), size=8, color="#e4572e")
scene = Scene2D(dot)
scene = scene.bind({scene.camera.ref("view"): Bounds2D(Vec2(0, 0), Vec2(10, 10))})

motion = dot.animate.position.to(Vec2(9, 9), duration=1.5, easing=ease.out_cubic)
animation = Animation(scene, motion)

animation.save("dot.svg", width=400, height=400)  # native animated SVG
animation.save("dot.gif", width=400, height=400, fps=30)  # needs kinetickit[raster]
animation.save("dot.html", width=400, height=440)  # needs kinetickit[interactive]

The point moves from (1, 1) to (9, 9) with cubic ease-out.

Animation(scene, motion=None, *, registry=..., interactions=None, accessibility=None)

sceneSceneBase

The scene: nodes, overlay and camera. 2D and 3D scenes are both accepted.

motionMotion | NoneDefault: None

The motion tree. None gives a still animation.

interactionsInteractionSpec | NoneDefault: None

Declarative interactions bound to node ids (Typography and accessibility).

accessibilityAccessibilityInfo | NoneDefault: None

Title, descriptions, language and the reduced-motion policy.

The facade that joins an immutable scene to a motion. frames() yields snapshots lazily, sample(t) returns the scene at one time, and save() picks an exporter from the destination suffix.

Animation.save(target, *, renderer=None, **options) → Any

targetstr | PathLike | Destination

A file path, a stream or another destination. The suffix of a path picks the format: .svg, .gif or .html.

rendererstr | NoneDefault: None

Force a renderer: vector, raster or interactive. None follows the format.

**optionsAny

Options of the chosen output, such as width, height, fps or title (Output formats).

Writes the animation and returns an ExportManifest. The write is atomic: a failed export leaves no file behind.

Scene2D(*nodes, overlay=(), camera=None)

An immutable collection of 2D nodes plus a camera. bind() returns a new scene with the camera view set instead of changing the original.

Point2D(
    *,
    id,
    opacity=1.0,
    z=0.0,
    visible=True,
    semantics=None,
    position=Vec2(x=0.0, y=0.0),
    size=4.0,
    symbol='circle',
    color=...,
    stroke=None,
    stroke_width=1.0,
)

idstr

The stable id. Motions, interactions and scene transitions find the node by it.

positionVec2Default: Vec2(x=0.0, y=0.0)

Where the point sits, in world coordinates.

sizefloatDefault: 4.0

The marker size in output units.

colorColor | strDefault: ...

Fill colour: a Color or a CSS-style string such as "#e4572e".

opacityfloatDefault: 1.0

From 0 (hidden) to 1 (opaque).

semanticsSemantics | NoneDefault: None

Role, label and reading order for assistive technology.

A circular 2D mark with a stable id, a position, a size, a colour and an opacity. Each of these can be animated through node.animate.

Bounds2D(min, max)

minVec2

The lower-left corner.

maxVec2

The upper-right corner.

An axis-aligned rectangle, used for camera views, clipping, layout and bounds.

Vec2(x, y)

xfloat

Horizontal component.

yfloat

Vertical component.

An immutable two-component vector for positions, directions and sizes.

ease.linear(u)
ease.in_quad(u), ease.out_quad(u), ease.in_out_quad(u)
ease.in_cubic(u), ease.out_cubic(u), ease.in_out_cubic(u)
ease.in_quart(u), ease.in_quint(u), ease.in_sine(u), ease.in_expo(u)
ease.cubic_bezier(x1, y1, x2, y2)

The easing namespace. Time and easing lists every function.

Reading the scene at a time

A scene and a time always give the same state, so you can ask for any moment without playing the animation.

print(animation.duration)  # 1.5
print(animation.sample(0.0).get("dot").position)  # Vec2(x=1.0, y=1.0)
print(animation.sample(0.75).get("dot").position)  # Vec2(x=8.0, y=8.0)
print(animation.sample(1.5).get("dot").position)  # Vec2(x=9.0, y=9.0)

At 0.75 seconds the progress is 0.5, and cubic ease-out gives \(1 - (1 - 0.5)^3 = 0.875\) of the way, so the point is at \(1 + 8 \times 0.875 = 8\).

Composing motions

A motion is a value. Combine motions with then, with_, delay, repeat, yoyo, reverse and trim, and give a moment a name with mark.

from kinetickit import Animation, Bounds2D, Point2D, Scene2D, Vec2

a = Point2D(id="a", position=Vec2(0, 0), size=8)
b = Point2D(id="b", position=Vec2(0, 5), size=8, opacity=0.0)
c = Point2D(id="c", position=Vec2(5, 5), size=4)
scene = Scene2D(a, b, c)
scene = scene.bind({scene.camera.ref("view"): Bounds2D(Vec2(-1, -1), Vec2(11, 11))})

motion = (
    a.animate.position.to(Vec2(5, 5), duration=1.0)
    .then(b.animate.opacity.to(1.0, duration=0.5).with_(c.animate.size.to(9, duration=0.5)))
    .mark("settled")
)
print(Animation(scene, motion).duration)  # 1.5

The GIF and HTML lines need their matching extras. Capability checks run before a destination is opened, so an unsupported combination raises CapabilityError and leaves no partial file (Output formats).

Quick start

Reading the scene at a time

Composing motions

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