Skip to main content
IFC export is experimental and may change. If you hit an exporter limitation or confusing output, reach out on Discord.

​
Overview

OpenGeometry can export B-Reps and scenes to IFC4 (text / Part 21 style). You can export a single B-Rep payload or export a whole scene through OGSceneManager. IFC export supports an optional semantics mapping that lets you control which IFC classes to emit and attach properties.

​
Initialization

Initialize the WASM module once before using OGSceneManager: 
import { OpenGeometry } from "opengeometry";

await OpenGeometry.create({ wasmURL: "/opengeometry_bg.wasm" });

​
Export APIs

​
exportBrepToIfc

import { OGSceneManager } from "opengeometry";

const manager = new OGSceneManager();
const result = manager.exportBrepToIfc(brepSerialized);

​
exportSceneToIfc / exportCurrentSceneToIfc

import { OGSceneManager } from "opengeometry";

const manager = new OGSceneManager();
const sceneId = manager.createScene("ifc export");

const result = manager.exportSceneToIfc(sceneId);
// or:
const result2 = manager.exportCurrentSceneToIfc();

​
Result type

export*ToIfc(...) returns an OGIfcExportResult:
​
text
string
IFC text output.
​
reportJson
string
A JSON string containing export statistics (elements written, semantics applied, fallbacks, and more).

​
Config JSON

All IFC exports accept an optional config_json string. If it is null, undefined, or an empty string, OpenGeometry uses defaults. If you provide config_json, it must deserialize into the full IfcExportConfig shape (required fields must be present). Example JSON payload: 
{
  "schema": "Ifc4Add2",
  "project_name": "OpenGeometry Project",
  "site_name": "OpenGeometry Site",
  "building_name": "OpenGeometry Building",
  "storey_name": "OpenGeometry Storey",
  "scale": 1.0,
  "error_policy": "BestEffort",
  "validate_topology": true,
  "require_closed_shell": true,
  "semantics": {
    "wall-1": {
      "ifc_class": "IFCWALL",
      "name": "Exterior wall",
      "description": "Demo export wall",
      "tag": "W1",
      "property_sets": {
        "Pset_WallCommon": {
          "Reference": "W1"
        }
      },
      "quantity_sets": {
        "BaseQuantities": {
          "Length": 6.0
        }
      }
    }
  }
}

​
Semantics mapping

The semantics map is keyed by your entity_id values in the scene. When you specify ifc_class, OpenGeometry validates it against the allowed list and:
  • Uses the requested class when it is supported
  • Falls back to IFCBUILDINGELEMENTPROXY in best-effort mode
  • Errors in strict mode
Supported classes:
  • IFCBUILDINGELEMENTPROXY
  • IFCWALL
  • IFCSLAB
  • IFCCOLUMN
  • IFCBEAM
  • IFCMEMBER
  • IFCDOOR
  • IFCWINDOW
  • IFCROOF
  • IFCSTAIR
  • IFCRAILING
  • IFCFOOTING

​
Examples

​
Export and download IFC in the browser

const result = manager.exportCurrentSceneToIfc();

const blob = new Blob([result.text], { type: "text/plain" });
const url = URL.createObjectURL(blob);

const link = document.createElement("a");
link.href = url;
link.download = "model.ifc";
link.click();

URL.revokeObjectURL(url);

​
Native-only file export

Native-only builds also expose exportSceneToIfcFile(...) (not available in browser/WASM builds).

​
Live demo

There is no dedicated IFC export demo page yet. Start from the demo index: OpenGeometry demos.
Last modified on March 14, 2026