scene_service.state.relations

Relation engine — pure-geometric predicates over the object registry. Runs at 1 Hz as its own asyncio task. Output is a list of (subject, predicate, target) triples cached on the engine and exposed via current() / served by the snapshot tools.

Classes

RelationEngine(registry, *[, period_s])	Periodic recomputation of pairwise relations + cached snapshot.
RelationTriple(subject_object_id, predicate, ...)

class scene_service.state.relations.RelationEngine(registry: ObjectRegistry, *, period_s: float = 1.0)

Bases: object

Periodic recomputation of pairwise relations + cached snapshot.

Read path: engine.current() returns the latest cached list. Reads don’t touch the registry lock — they grab the engine’s local cache that the periodic tick refreshed atomically. So MCP query calls don’t have to wait for ingest.

current() → list[RelationTriple]

async start() → None

async stop() → None

class scene_service.state.relations.RelationTriple(subject_object_id: 'str', predicate: 'str', target_object_id: 'str')

Bases: object

predicate: str

subject_object_id: str

target_object_id: str