A character sprite pipeline for Unreal Engine's Paper2D. Purpose-built visual editors for flipbooks,
per-frame hitboxes, sockets, root motion, and frame timing; frame-anchored Cues with authorable Cue
Types; layered character appearance with runtime customization; Animation Map combo chains;
sprite-sheet extraction and Aseprite (.ase) import with diff-based reimport; Character Catalog,
Effect and Combat Profiles; and runtime debug visualization — instead of hand-editing data assets.
Supported engines: UE 5.0 – 5.8. Every release is built against all nine.
- Character Profile — one asset owning a character's animations, per-frame attack/hurt boxes, sockets, root motion, frame timing, curves, gameplay tags, and transitions. Each logical animation may also own a partial 3–16-slot multidirectional art set while keeping one base identity. The six-tool workspace (Animations, Hitbox, Sprite, Frame Timing, Frame Cues, Root Motion) shares one radial direction preview and authoring control.
- Animation Map — a node graph over your transitions. Author combo chains visually with Chain Start / Chain End markers, then query them from Blueprint by flipbook or by exact tags.
- Frame Cues — frame-anchored notifies with deterministic Cue and Cue State lifecycles and per-placement Frame Start / Frame End trigger edges. A Cue Type you author carries reflected payload and its own behavior (On Cue Triggered, or On Cue Begin / Update / End), which runs immediately before the listener broadcast; your receivers still own persistent state and every release. One built-in cue ships — Spawn Flipbook Cue, a one-shot effect with an offset you drag directly in the preview viewport — and every other cue is one you author, inside a deliberately narrow, cook-safe, network-aware envelope.
- Character Layers — layered art with stable layer IDs, exclusive groups, appearance presets, and two delivery modes: Fixed / Baked (compiles to ordinary flipbooks) or Runtime Customizable (swap skins, wearables, and cosmetic effects at runtime).
- Sprite tooling — sprite-sheet extraction with uniform-bounds detection, bulk multi-texture
extraction, cross-sheet alignment, Aseprite (
.ase) import and diff-based reimport, de-bake, and an Aseprite-style pixel draw tool for editing flipbook frames in place. - Character Catalog, Effect Profile, Combat Profile — a project-wide character roster, a reusable visual-effect library, and an advisory utility-scoring layer for AI attack selection.
- Optional multiplayer — opt-in, intent-based appearance replication. Single-player is the default and costs nothing.
Runtime debug visualization is available through console variables
(Paper2DPlus.ShowHitboxes 1, Paper2DPlus.ShowFrameData 1) in PIE and development builds.
From Fab (recommended) — install through the Epic Games Launcher, then enable Paper2D Plus in Edit → Plugins.
From source — clone into your project's Plugins/ directory:
YourProject/
YourProject.uproject
Plugins/
Paper2DPlus/
Then right-click the .uproject → Generate Visual Studio project files, and build. A C++ project
is required to compile from source; Blueprint-only projects should use the Fab build.
Clone the whole repository.
Config/carries the CoreRedirects that keep assets authored in earlier versions loading, andShaders/carries the global shaders the optional hybrid appearance compositor needs. A partial copy ofSource/alone will load but will silently break redirects and composite rendering.
Enabled automatically via the .uplugin: Paper2D, GameplayTagsEditor, DataValidation.
PaperZD is optional and detected at build time. With it installed you get sequence authoring and flipbook→sequence resolution; without it the plugin compiles and runs with those paths disabled. Paper2D Plus never takes ownership of playback decisions from PaperZD.
| Module | Type | Purpose |
|---|---|---|
Paper2DPlus |
Runtime | Cooked character/profile data, Frame Cue dispatch, layer composition, appearance, catalog, effects, combat scoring, collision and root-motion helpers. |
Paper2DPlusBlueprintNodes |
UncookedOnly | Custom K2 nodes that expand to cooked runtime calls, so game Blueprints carry no editor-module dependency. |
Paper2DPlusEditor |
Editor | Every authoring surface: profile/layer/catalog/effect/combat editors, extraction and import pipelines, validation, and bake tooling. |
Start with the Designer Guide.
| Guide | Covers |
|---|---|
| Designer Guide | The overall workflow and vocabulary. |
| Multidirectional Animations | Direction sets, the radial editor, Blueprint resolution, and the PaperZD boundary. |
| Frame Cues | Authoring Cue Types, their behavior, and writing receivers. |
| Layer Authoring | Layers, presets, exclusive groups, baking. |
| Runtime Appearance | Runtime-customizable characters, hybrid rendering, crowd budgets. |
| Character Catalog | Project-wide roster, groups, companions. |
| Effect Profile | The visual effect library. |
| Combat Profile | Advisory attack scoring. |
| Paper2DPlus and PaperZD | Where the boundary sits. |
| Authority Contract | Per-API authority rules for networked projects. |
| Testing and Release Verification | The automation suite and the nine-engine release gate ladder, with recorded results. |
Contributors should read ONBOARDING.md for the architecture map and conventions.
The plugin ships a validation pass that reports missing hitboxes, dangling transition targets,
duplicate tags, broken layer references, and cook-safety problems. Run it per asset from the editor
(Asset → Validate Character Profile…), across the Content Browser, through Unreal's Data
Validation, or headlessly via the Paper2DPlusValidate commandlet, which emits a machine-readable
JSON report.
How the plugin itself is verified — the automation suite and the release gate ladder run against all nine engines before every release — is documented in Testing and Release Verification.
Semantic versioning. See CHANGELOG.md for what each release contains and RELEASING.md for the rules that decide the version number.
Upgrading across a major version can require opening and resaving assets on the previous version first — the changelog entry for that release always says so explicitly.
EngineVersion in the .uplugin pins a single engine because Fab requires one build per engine
version. It is not the supported range; the supported range is UE 5.0–5.8, stated above.
MIT — see LICENSE. You may use, modify, and redistribute this source, including commercially, provided the copyright notice is retained.
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- Fab: https://www.fab.com/listings/7600dc00-077e-41db-9222-87f4240e26be (or open in the Epic Games Launcher)
Built by Infinite Gameworks.