IfcIO

IfcIO is a fast, 100% managed .NET library for building, reading, and exporting Industry Foundation Classes (.ifc) files compliant with IFC2x3 Coordination View V2.0 and IFC4 Design Transfer / Reference View without third-party dependencies or native code.

Built clean-room under the IOExtend organization as the shared open-standards IFC foundation for AEC/BIM projects (including NwcIO and RvtIO).

Key Features

  • Full Model Ingestion & Export (IfcModel):
    • Reconstruct complete spatial hierarchy (Project, Site, Building, Storeys), elements, properties, materials, and 3D meshes from any .ifc or .ifczip file.
    • Multi-line STEP statement accumulation and quote-aware tokenization in StepReader and high-throughput streaming in StepWriter.
  • IFC4 Modern Mesh Tessellation (IfcTriangulatedFaceSet):
    • Encodes geometry using compact IfcTriangulatedFaceSet and IfcCartesianPointList3D under representation type 'Tessellation' for IFC4 exports (>60% smaller file sizes than legacy faceted B-Rep).
  • Direct 3D Exporters (glTF 2.0 & Wavefront OBJ):
    • Instant conversion of any IFC model to binary glTF 2.0 (.glb) with PBR metallic-roughness materials and vertex normals, or Wavefront OBJ (.obj + .mtl).
  • PKZip Compressed IFC (.ifczip):
    • Built-in transparent compression and decompression for standard .ifczip archives with zero native dependencies.
  • Cross-Platform CLI Tool (ifcio):
    • Global .NET CLI tool (IfcIO.Cli on NuGet) providing info, export, pack, unpack, clash, diff, view, and validate commands.
  • buildingSMART 22-Character GlobalId (IfcGuid):
    • Standard base64-like buildingSMART encoding (0-9, A-Z, a-z, _, $). Bidirectional conversion between 128-bit .NET Guid and 22-character IFC GlobalId.
  • 3D Geometric Clash Detection & Revision Diff:
    • Built-in Möller triangle collision, proximity clustering, structural grid location assignment, revision comparison, and buildingSMART BCF 2.1 zip reporting.

The library targets .NET 8 and .NET 10, uses 100% pure managed code with zero native dependencies, and supports Windows, Linux, and macOS.

Where to go next

  • Getting started: install the package or CLI tool and run a first export or model query.
  • Public API: supported surface and key entry points of the library.
  • API reference: complete API documentation generated directly from XML source docstrings.
  • Source on GitHub and DeepWiki for an automated architectural overview of the repository.

IfcIO is licensed under the MIT License and is an independent implementation of the ISO 10303-21 STEP and buildingSMART specifications. buildingSMART and IFC are registered trademarks of buildingSMART International Ltd.

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