SpineCullingEnvelope

SpineCullingEnvelope = { bounds: SpineAABB; kind: "certified"; source: "explicit"; } | { bounds: SpineAABB; coverage: SpineScanCoverage; era: string; kind: "observed"; sampleStep: number; source: "animation-scan"; } | { kind: "unknown"; }

Defined in: spine/spineBounds.ts:52

The extent culling is allowed to trust, and how much that is worth.

observed carries the era it was scanned from and retires with it: what one generation’s bytes did is no promise about the next. A certificate is about the asset, so it carries no era at all.