@fourjs/scene

Scene graph — the shared model all four pillars act on. Part of fourJS.

Implements §6–8, §42–43, and §46–48 of docs/SPECIFICATION.md; shipped across Phases 1–3 and 7. Right-handed Y-up transforms, radians.

What's here

• Hierarchy — Node (single inheritance over @fourjs/core's EventEmitter, typed NodeEventMap, component host), Group, Scene, and NodeSpace (§8 mode on the node, with NODE_SPACE_SERIALIZER).
• Transform — position/rotation/scale with a dirty channel driven by math change-hooks, plus resolveWorldTransform / resolveWorldTransforms (world matrices resolve per fixed step; staleness tracking includes parent identity).
• Transform authority (§42) — TransformAuthority (manual, animation, kinematic, physics, blended, constraint, network), DEFAULT_TRANSFORM_AUTHORITY, and warnAuthorityConflict (conflicts warn, never silently overwrite; takes a structural AuthorityNode).
• Cameras and viewport (§47–48) — PerspectiveCamera / OrthographicCamera / ScreenCamera with depth-range-parameterized projection, Viewport / createFullscreenViewport. Camera rigs/controls belong to @fourjs/motion (OrbitRig, FollowRig, LookAtConstraint; TrackballRig lives here because it is defined over a viewport in screen space).
• Render interpolation (§43) — PoseBuffer (lerp/slerp between physics poses), PoseSnapshotSystem / createSnapshotSystem, and PoseTarget (position + rotation history; the §19 blending input captured by @fourjs/physics's capture system).
• Bones and skeletons (§54) — Bone is a node; Skeleton.update(skinRoot, worldOf?) writes the joint palette. Omit worldOf for resolved worlds; the interpolated render list supplies a provider that composes §43 local poses, then runs the palette product. Palettes are never matrix-lerped.

Staged / not yet implemented

• A render/UI consumer that places a node from NodeSpace's presentation modes (screen / viewport / camera / billboard). The declaration and §79 pair ship; placement is still §47/§48/§74.

Unit tests are colocated in tests/ per §92.

Workspace name @fourjs/scene; publishes as @danielsimonjr/fourjs-scene.