KineticKit

Domain-neutral engine for precise, deterministic 2D and 3D animation.

KineticKit owns its scene model, animation model, rendering ports, interaction model and animation output. It depends on no visualization package: anything can take part by being translated into KineticKit points, lines, paths, shapes, text assets, meshes and surfaces.

One scene and one timeline drive three outputs:

kinetickit[studio] installs the raster and interactive capabilities together. Python 3.10–3.13.

Status: 1.0 beta. The contracts listed in docs/compatibility.md are intended to be stable; they may still change between pre-releases, always with a changelog entry. See CHANGELOG.md.

Quick start

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]

Everything is an immutable value: nodes, scenes, motions and snapshots. A motion is composed with .then() / .with_() / .delay() / .repeat() / .yoyo() / .reverse() / .trim(), and the same scene and time always give the same state, independent of any renderer or wall clock.

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")
)

3D uses the same builders:

from kinetickit import Camera3D, Scene3D, Surface3D, Vec3

scene = Scene3D(surface, camera=Camera3D(position=Vec3(5, -6, 4), target=Vec3(0, 0, 0)))
Animation(scene, scene.camera.animate.position.to(Vec3(-5, -6, 4), duration=2.0)).save("orbit.html")

What you get

• Timing: deterministic frames (N = max(2, round(D·fps)), both endpoints included), easing families plus cubic Bézier, an extensible interpolator registry, keyframes, markers.
• Scenes: precise 2D points, lines, paths, shapes, groups (transform, clip), overlay and camera; 3D points, polylines, meshes, surfaces, lights, perspective/orthographic cameras.
• Morphing: automatic path normalization, mesh/surface correspondence with explicit overrides and diagnostics, and SceneTransition between scenes by stable ids.
• Interaction: portable events and data-only actions bound to node ids, playback state machine, controls; required bindings fail before output, optional ones degrade explicitly.
• Accessibility: per-object roles/labels/descriptions/reading order, reduced-motion policy, text alternatives and keyboard-operable controls.
• Typography: text arrives as a neutral TextAsset; the optional GlyphKit adapter turns caller-provided fonts into assets and embeds permission-checked subsets.
• Quality: conformance fixtures and suites, golden artifacts, performance budgets.

Outputs, fallbacks and what each format preserves or degrades: docs/outputs.md. Migrating from MosaicKit or utility-viz animation: docs/migration.md.

Architecture

Boundaries are enforced by import-linter contracts and AST tests. Third-party engines (Matplotlib, Plotly, Pillow) live only in private _* modules and never appear in public API.

Development

uv sync --all-extras
uv run pytest
uv run ruff check . && uv run ruff format --check . && uv run mypy && uv run lint-imports
uv run python -m kinetickit.conformance      # shared suites + performance budgets

Examples live in examples/ and use only public API.