OptionalIfcAggregate parents/children (IfcRelAggregates): 'up' walks to
RelatingObject only, 'down' to RelatedObjects only, 'both' walks
both directions, 'none' skips it. Default 'both'.
OptionalIfcAn included object's material assignment (IfcRelAssociatesMaterial).
Default true.
OptionalIfcBFS depth (both directions) to walk IfcRelConnectsPathElements from an
included element — e.g. a wall's structurally-connected neighbour.
Default 0 (no expansion).
OptionalIfcThe spatial containment chain (IfcRelContainedInSpatialStructure) up to
storey/building/site. Default true; regardless of this flag,
IfcProject is ALWAYS included — a STEP file with no project is not a
valid reproduction of anything.
OptionalIfcAn included object's property sets (IfcRelDefinesByProperties).
Default false — psets are the majority of what this feature exists to
strip, so expanding them is opt-in, and turning this on still pulls in
ePSet_MapConversion/ePSet_ProjectedCRS style georeferencing psets
unless those are separately excluded.
OptionalIfcAn included object's IfcTypeObject (IfcRelDefinesByType). Default true.
OptionalIfcThe filler↔opening↔host chain (a window/door and the wall it sits in).
Default true.
OptionalIfcNesting parents/children (IfcRelNests) — a separate EXPRESS
relationship from IfcRelAggregates even though the parser folds both
into the same aggregation edge type on RelationshipGraph; this option
is split out from the one above by REL ENTITY TYPE, not by graph edge,
so a caller can toggle them independently. Default 'down'.
OptionalIfcOpenings of an included host element. Default true.
Which relationship kinds
collectRelatedEntitiesexpands from the seed selection, and how far. Every boolean defaults to what the doc comment says, not tofalse— an omittedRelatedEntityOptions(or an omitted field within one) must reproduce the bug the seed exhibits, which usually needs its host/opening/type/material context, not a bare, disconnected element.