IOExtend

High-performance, pure managed .NET libraries and cross-platform CLI tools for BIM and CAD interoperability.

Read, analyze, convert, and federate complex building models without proprietary runtime licenses, native wrappers, or CAD software installed.

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IOExtend provides a unified suite of independent, zero-dependency .NET engines and viewer tools designed for high-throughput cloud microservices, CI/CD pipelines, web backends, and desktop engineering software.

Project	Primary Formats	Key Capabilities	Documentation	NuGet	Release	Brand Palette
RvtIO	.rvt, .rfa (Revit 2020–2026, 2027 partial)	Elements, parameters, geometry, file metadata and project information, FilteredElementCollector queries, IFC2X3 and JSON export				Amber #F2A33A
NwcIO	.nwc, .nwd, .nwf	Navisworks binary LcUStream parser, scene hierarchy and meshes, clash detection and clash matrix, BCF 2.1, 4D TimeLiner, IFC2X3/IFC4, glTF, OBJ, HTML and JSON export				Azure Blue #3B82F6
IfcIO	.ifc, .ifczip	Pure managed ISO 10303-21 STEP engine for buildingSMART IFC2x3 & IFC4, tessellated geometry, glTF/OBJ export, 4D/5D schedules, IDS audit, clash detection, BCF 2.1				Electric Violet #A855F7
DwgIO	.dwg (AutoCAD R2004–R2018)	DWG version detection (R13–R2018), section container and decompression, drawing metadata and thumbnail, LINE/CIRCLE/ARC/POINT geometry, JSON export				Sky Blue #38BDF8
IOViewer	.glb, .obj, JSON → .html	Standalone single-file WebGL/HTML viewer: ViewCube, section planes and section box, BIM property tree, measurement, 4D TimeLiner player, clash inspection				Cyan #06B6D4

Each engine reads a native format and writes open formats that the other tools consume. For example, a Revit model can go .rvt → RvtIO → .ifc → IfcIO → .glb → IOViewer → .html.

flowchart LR
  rvt[".rvt / .rfa"] --> RvtIO
  nwc[".nwc / .nwd / .nwf"] --> NwcIO
  dwg[".dwg"] --> DwgIO

  RvtIO --> ifc[".ifc"]
  NwcIO --> ifc
  ifc --> IfcIO

  NwcIO --> glb[".glb / .obj"]
  IfcIO --> glb
  glb --> IOViewer
  IOViewer --> html[".html viewer"]

  NwcIO --> bcf[".bcfzip (BCF 2.1)"]
  IfcIO --> bcf

  RvtIO --> json[".json"]
  NwcIO --> json
  IfcIO --> json
  DwgIO --> json

  classDef rvt stroke:#F2A33A,stroke-width:3px
  classDef nwc stroke:#3B82F6,stroke-width:3px
  classDef ifcio stroke:#A855F7,stroke-width:3px
  classDef dwgio stroke:#38BDF8,stroke-width:3px
  classDef viewer stroke:#06B6D4,stroke-width:3px
  class RvtIO rvt
  class NwcIO nwc
  class IfcIO ifcio
  class DwgIO dwgio
  class IOViewer viewer

1. 100% Pure Managed .NET:
   • Zero C/C++ native dynamic libraries (.dll, .so, .dylib).
   • Runs seamlessly inside minimal Alpine Linux Docker containers, AWS Lambda, Azure Functions, macOS ARM64/x64, and Windows.
2. Zero Proprietary SDK Dependencies:
   • Operates completely standalone without Autodesk Revit, Autodesk Navisworks, AutoCAD, or closed-source license daemons.
3. Clean-Room Specification:
   • All engines are authored from scratch using first-principles format analysis, official ISO/buildingSMART standards, and documented specifications.
   • Zero copyrighted code, zero decompiled source, and zero vendor header files.
4. Extreme Performance:
   • Streaming zlib and Deflate decompression without memory spikes.
   • Sub-second parsing of multi-hundred megabyte models with tens of thousands of geometry meshes.

Install any of the libraries via the .NET CLI:

# Autodesk Revit engine
dotnet add package RvtIO

# Autodesk Navisworks engine
dotnet add package NwcIO

# buildingSMART IFC engine
dotnet add package IfcIO

# Autodesk DWG engine
dotnet add package DwgIO

# Standalone WebGL/HTML viewer generator
dotnet add package IOViewer

Every project ships a command-line tool for CI/CD scripting:

# Install the CLI tools globally
dotnet tool install --global RvtIO.Cli
dotnet tool install --global NwcIO.Cli
dotnet tool install --global IfcIO.Cli
dotnet tool install --global DwgIO.Cli
dotnet tool install --global IOViewer.Cli

# Export a Revit project to IFC
rvtio project.rvt project.ifc

# Convert a Navisworks model to binary glTF and run clash detection with BCF output
nwcio model.nwc model.glb
nwcio clash arch.nwc mep.nwc --bcf clashes.bcfzip --tolerance 0.01

# Inspect an IFC model
ifcio info Building.ifc --report

# Inspect a DWG drawing
dwgio inspect drawing.dwg

# Generate a standalone HTML viewer from a GLB model
ioviewer model.glb -o viewer.html

• All repositories in the IOExtend organization strictly enforce clean-room policies.
• Repositories contain no confidential customer models, vendor files, or proprietary binaries.
• Automated CI workflows test against procedural synthetic data and isolated local environment fixtures (*_TEST_FILES).
• For security inquiries, please review the SECURITY.md file in each repository.