Cascade : UI Toolkit Animation, Tweens & Transitions

UI Toolkit (UIElements) gave you components. It never gave you motion.

Cascade adds spring animation, tweens, variants, stagger, screen transitions and hover/press micro-interactions — written in C#, built in the inspector with live preview, or generated by an AI assistant.

PLAY IT FIRST - https://twitchedd.itch.io/cascade-blocks

Every pixel of motion in that game is Cascade.

DOCS - https://twitchedd.github.io/cascade/docs/

Getting started, guides, recipes and the full API reference.

WHY PAY WHEN FREE TWEEN LIBRARIES EXIST?

Free tween libraries animate values from code, and they're great at it. Cascade is a UI Toolkit motion SYSTEM: your non-programmer teammates build entrances, hover states and screen transitions from the inspector with live preview; you get UITK-native lifecycle safety (panel detach, display toggling, USS quirks handled), springs with velocity handoff, variants, and a preset library — out of the box.

WHAT'S INSIDE

- Springs that survive interruption — velocity relay, no dead-stops

- AI-ready: describe motion to your assistant, paste back validated JSON, it plays; errors coach the AI to fix itself (ships with AI-GUIDE.md + JSON schema + prompt pack)

- Variants: To("open") / To("closed") named states

- Stagger any list of elements in one line

- Enter/exit + screen transitions with display-safe Show/Hide

- Hover / press / focus micro-interactions, interruption-safe

- No-code UIAnimator: selector rules, preset browser, create-in-place, edit-mode live preview

- 10 Starter Presets + full demo gallery with copyable code per section

- Reduced-motion accessibility (full / reduced / crossfade / none)

- Zero per-frame GC (test-enforced), zero dependencies, async/await throughout

- Unity 6000.0+, every Unity-supported platform, no native code

FOUR READY-MADE DEMO SCREENS

See Cascade in real interfaces, not just buttons: a game HUD overlay (damage-chip health bar, screen shake, hotbar cooldowns, wave banner), an editorial shop (stagger, hover lift, fly-to-bag), an audio studio (looping meters, crossfades) and a project dashboard (drawers, variants, page transitions). Each is a complete scene with a short, commented driver script to learn from.

TIERS

Cascade Lite (free, MIT) covers the core tween engine with the full verb set and async/await. Cascade Pro adds everything above. Both install as clean UPM packages.