ThatOpen Property Queries and Classification

Overview

ThatOpen provides two complementary systems for organizing and extracting data from loaded BIM models:

1. Classifier — Groups fragment items by IFC category, building storey, model, or custom criteria. Produces ModelIdMap results for downstream operations (hiding, highlighting, data extraction).
2. FragmentsManager.getData() — Extracts IFC property data (property sets, quantity sets, type information, relationships) for targeted items.
3. ItemsFinder — Searches items across models using query parameters with category, attribute, and relationship filters.

All three operate on the fragment layer, not raw web-ifc. For direct web-ifc property access (GetLine, GetPropertySets), see thatopen-core-web-ifc.