Model Federation

Overview

Model federation is the practice of loading multiple IFC models into a single 3D scene, aligning them to a shared coordinate system, and controlling their visibility independently. In ThatOpen Engine, federation is not a single component but a workflow that combines FragmentsManager (loading, alignment), Hider (visibility), BoundingBoxer (spatial queries), and Classifier (per-model grouping).

Core principle: Each model loaded via IfcLoader produces an independent FragmentsModel. These models may originate from different authoring tools with different world origins. ALWAYS apply coordinate alignment before interacting with multi-model scenes.

Federation workflow:

Load Model A (IfcLoader) → Set as base coordination model