crosstech-impl-ifc-to-threejs

Converting IFC to Three.js for web BIM visualization involves using web-ifc and @thatopen/components to parse geometry, preserve metadata, and apply per-element placement transforms for accurate rendering in a Y-up scene.

IFC coordinate orientation mismatches in Three.js occur because IFC uses Z-up while Three.js uses Y-up, requiring per-element placement transforms during rendering to prevent axis loss and ensure accurate geometry display.

web-ifc supports raycasting for element selection in BIM viewers by integrating Three.js raycasting with @thatopen/components, enabling interactive selection and property panel access for IFC elements.

You can cache IFC geometry in Three.js using Fragments-based caching, which enables near-instant re-loads in subsequent visits by storing processed geometry and metadata instead of re-parsing the original IFC file.

Handling large IFC models in a Three.js viewer requires memory management and Fragments-based caching to optimize performance, alongside choosing between a component-based viewer or a custom pipeline based on model scale.

@thatopen/components is used to display IFC properties in Three.js by providing integrated property panels and raycasting-based element selection, offering a complete workflow for interactive BIM viewing.