This example composes EVEngine's UI-neutral editor SDK into a project-specific combat action editor. It uses the canonical eve.action.timeline asset model, native hit testing and drag preview, one-step transactions, undo/redo, and deterministic preview events. Its document toolbar opens two independently persisted montage assets, projects dirty state into tabs, and protects unsaved work when a tab is closed. The 3D viewport is driven by the same preview cursor as the active timeline. The viewport also runs a two-fighter playtest: edited combat:damage payloads flow from Montage runtime events into the canonical Combat damage runtime, while movement and health stay owned by that runtime.

Run on Windows:

make run/win32-debug GAME=examples/combat-action-editor

Controls:

Switch between Light Attack and Follow-up document tabs. An asterisk marks unsaved edits; closing a dirty tab requires a second explicit click to discard its changes.
The save icon or Ctrl+S atomically writes the active document under Content/Actions, validates it, and registers its stable GUID sidecar with AssetDB. Open Asset provides a searchable picker over indexed, validated Montage documents; selecting an already-open GUID activates its existing tab.
The compact transport icons control deterministic action preview; Space toggles playback.
Click empty timeline space to seek.
Timeline blocks project registry display names, compact resource/parameter details and stable semantic mini-previews for VFX, audio, prefabs, cameras, hitboxes, defense, input and movement. These visuals are derived UI state and never become duplicate fields in the action asset.
Drag an item body to move it; drag a state edge to resize it.
Selecting an animation section, instant notify, or state window automatically opens the Action Block inspector. Its timing sliders commit validated, undoable transactions; the toolbar deletes the selected block and exposes the same undo/redo history. Audio, VFX and Prefab blocks expose typed resource, playback, lifecycle and shared spatial controls. VFX states can atomically fit their block duration to the trimmed clip at 1.0x speed, or fit the clip end to the current block duration. When the Particles provider is loaded, Use Asset Duration reads the real finite emitter/lifetime data instead of asking the author to copy a duration by hand. Audio additionally exposes a random clip URI pool, deterministic pitch variation, spatial blend and attenuation distances, and exit fade controls; the advanced payload JSON remains available for extensions. Each typed edit merges only its fields, preserves unknown payload data, validates the complete result through the notify registry, and commits one undo step. Notify type and payload JSON are also editable for advanced authoring; registered type, Instant/State shape and typed payload contracts are validated before the document changes. Enabled persists in schema v4; disabled blocks remain visible and editable but do not emit preview/runtime events. New Block opens a compact registry-backed picker for the target track, Instant/State type, duration and payload; valid starter payloads make every built-in type immediately insertable at the playhead. Copy/paste uses the native deep-copy clipboard and pastes relative to the current playhead. Ctrl/Shift-click adds blocks to the selection; the inspector reports the complete selection range and aligns starts or ends. Dragging one selected body moves the whole selection, while copy and delete operate on every selected block in one undoable transaction. Dragging also uses an eight-pixel magnetic threshold to snap against the playhead, physical splits, animation-section edges and other block edges, after applying the deterministic frame grid. The Track tab selects and renames tracks, toggles mute/lock state, creates all eight semantic track kinds, deletes tracks, and deep-copies whole tracks across the open document tabs. Selecting an animation section reveals its source URI, exact start/end, blend-in duration, source trim range and blend curve. New Section creates validated sections at explicit timeline ranges. Persisted UI state is migrated when newer editor controls are introduced, preserving open document state. The Montage tab edits play rate, looping, Foot IK, animation layer, default blend windows and Root Motion masks. Valid changes update both the persisted timeline and the already prepared runtime preview. Its Physical Sections controls add a split at the live playhead, move an indexed split or delete it; every operation preserves strict ordering and participates in the same undo/redo history used by section jumps and adaptive time warping. The Joint tab retains skeleton transform and key editing in the same compact side panel.
The Presentation lane includes a cubic master-volume parameter curve. Its sampled shape is drawn inside the block; native inspector/script APIs edit its keys through the same undoable timeline transaction.
The impact camera cue drives the preview's real CameraController with a deterministic position, rotation and FOV impulse.
Undo / Redo (or Ctrl+Z / Ctrl+Y) operates on the native timeline transaction history.
Use the transport speed controls or Q / E / R for 0.5x / 1.0x / 1.5x playback. The HUD shows the authoritative physical section, section progress, mixer weight and current rate.
Hold the right mouse button over the preview to orbit; use the mouse wheel to zoom.
Use WASD to move the player through CombatLocomotionRuntime. When playback crosses the damage notify, target health and reaction update above the viewport. Editing that block changes the next hit without a demo-only damage model. The active editor snapshot is also registered as an AbilityDefinition; its physical sections become action phases, and the preview HUD reports the native Ability phase and cooldown instead of maintaining script timers. The skinned KayKit character consumes the Montage runtime pose directly, so section cross-fades, jumps and blend-out are visible on the real skeleton. Joint/key edits deep-copy the rebuilt clip into the running Montage and resample the current cursor without retaining editor-owned clip pointers. Saving hot-reloads that definition without revoking its grant. Press J while the authored input:combo-window is open to resolve its gameplay tag through matchingAbilities, replace the active exclusive Ability, and replay the montage through the fixed dual-slot coordinator. The outgoing execution keeps its clip snapshot and fades out while the replacement fades in, so combo transitions remain continuous. Input outside the authored window is rejected. Naturally completed montages retain their final weighted pose until another montage cross-fades it out, avoiding a one-frame snap back to the bind pose.

The preview and timeline headers show the current selection, playback state, edit revision and the last emitted event so every interaction has visible feedback.

The bundled KayKit Adventurers character, sword and animation libraries are CC0. See assets/kaykit/LICENSE-KAYKIT-ADVENTURERS.txt and assets/kaykit/LICENSE-KAYKIT-ANIMATIONS.txt.