ExtrabbitCode.Inventor.MetaReader - read Inventor files without Inventor

Reads metadata out of Autodesk Inventor .ipt / .iam / .idw / .ipn files - and neutral STEP (.stp / .step) files - directly from their bytes, no Autodesk Inventor installation required. The Windows viewer also shows the model in interactive 3D, generated with Inventor or with a built-in converter that needs no Inventor at all.

The Windows desktop viewer ships on the Microsoft Store - it installs, updates and code-signs itself, with nothing else to set up:

(The core library and CLI are cross-platform and built from source - see Build & run.)

Screenshots

The Windows viewer - the Home screen (drop a file, or reopen a recent one), and a document open with its thumbnail, key iProperties and every property grouped by set:

And the 3D viewer - spin the model, give every body its own colour, and mark it up, all generated without Inventor installed:

It exploits the fact that Inventor files are standard OLE Compound File Binary containers and that all iProperties live in standard OLE Property Sets. See docs/INVENTOR-FILE-FORMAT.md for the full reverse-engineering write-up.

What it extracts

• Document type (part / assembly / drawing / presentation) from the root CLSID
• All iProperties - Part Number, Designer, Material, Project, Status, Description, custom properties, dates, "Last Updated With", etc.
• Cached mass / volume / surface area / density (with the Valid Mass Props caveat)
• The embedded preview thumbnail (PNG/BMP)
• Referenced files (assembly components, the model a drawing documents)
• Per-model-state iProperties - read every model state's properties at once, without switching states in Inventor, including a diff of what changes between states. *(For complete data, enable Inventor 2027+'s Generate All Model States on Save
  • right-click the Model States browser node. Otherwise a state's values only appear once that state has been recomputed in Inventor; until then the tool shows (not cached) instead of guessing.)*
• Model States and the originating template / version provenance
• STEP files (.stp / .step) - the ISO-10303 header (author, organization, schema), entity counts, products and solid bodies
• The raw CFB storage/stream tree, and any individual stream

In the 3D viewer

The Windows app turns any part or assembly into an interactive 3D view - generated once with Inventor's own translator, or with a built-in converter that reads the mesh cached in the file and needs no Inventor at all. On top of that:

• Body coloring - give every part its own colour with one click
• Redlining - draw, add text, or paint straight onto the model surface; markup lives on layers saved with the cached viewable
• An interactive reference graph with three layouts and node thumbnails
• STEP models in 3D, converted in-app with Open CASCADE

See the documentation site for the full tour.

Projects

ExtrabbitCode.Inventor.MetaReader.slnx
├─ src/
│  ├─ InventorMeta/        cross-platform core library (the parser)  - net10.0
│  │  ├─ Cfb.cs              OLE Compound File Binary reader
│  │  ├─ OlePropertySet.cs   OLE property-set decoder
│  │  ├─ InventorProps.cs    Inventor-specific property/FMT mapping
│  │  ├─ ReferenceGraph.cs   referenced-file resolution
│  │  └─ InventorDocument.cs public facade over the above
│  ├─ InventorMeta.Cli/    command-line tool  ("invmeta")            - net10.0
│  └─ InventorMeta.App/    WinUI 3 desktop viewer                    - net10.0-windows
├─ tests/
│  └─ InventorMeta.Tests/  xUnit test suite for the core library    - net10.0
├─ docs/
│  └─ INVENTOR-FILE-FORMAT.md   reverse-engineering write-up
└─ documentation/         documentation website (Vite / React Router)

The core library (the src/InventorMeta project, namespace ExtrabbitCode.Inventor.MetaReader) has zero external dependencies and is the reusable piece - drop it into your own apps or Inventor add-ins. The CLI and WinUI app are thin front-ends over the same InventorDocument class.

Build & run

CLI (cross-platform)

dotnet build src/InventorMeta.Cli -c Release

# friendly report
dotnet run --project src/InventorMeta.Cli -- info   SamplePart.ipt
# per-model-state iProperties + what differs between states
dotnet run --project src/InventorMeta.Cli -- states SamplePart.ipt
# everything as JSON
dotnet run --project src/InventorMeta.Cli -- json   SamplePart.ipt
# every property in every property set
dotnet run --project src/InventorMeta.Cli -- props Assembly1.iam
# extract the thumbnail
dotnet run --project src/InventorMeta.Cli -- thumb SamplePart.idw out\thumb
# raw container tree / one stream / dump all streams
dotnet run --project src/InventorMeta.Cli -- tree    SamplePart.ipt
dotnet run --project src/InventorMeta.Cli -- cat     SamplePart.ipt /UFRxDoc
dotnet run --project src/InventorMeta.Cli -- extract SamplePart.ipt out\streams

After dotnet build, the binary is invmeta(.exe) in the project's bin/Release.

WinUI 3 viewer (Windows)

dotnet build src/InventorMeta.App -c Release -r win-x64
# launch (optionally with a file to open immediately):
src/InventorMeta.App/bin/Release/net10.0-windows10.0.19041.0/win-x64/InventorMeta.App.exe SamplePart.ipt

Open a file (button or drag-and-drop) to see the thumbnail, key iProperties, a grouped view of every property, references & model states, and the raw file structure. The Export JSON button writes the full metadata. The app is built self-contained (WindowsAppSDKSelfContained), so the Windows App Runtime does not need to be pre-installed.

Library usage

using ExtrabbitCode.Inventor.MetaReader;

var doc = new InventorDocument(@"C:\path\SamplePart.ipt");
Console.WriteLine(doc.DocumentType);                 // "Inventor Part (.ipt)"
Console.WriteLine(doc.Summary["Part Number"]);       // "SamplePart"
foreach (var r in doc.References) Console.WriteLine(r);
if (doc.Thumbnail != null)
    File.WriteAllBytes("preview." + doc.ThumbnailExt, doc.Thumbnail);
string json = doc.ToJson();

Scope

Metadata, properties, references and the preview are fully and stably readable. The parametric model and B-Rep geometry live in the proprietary RSeStorage database and are not decoded - for geometry, export to STEP/SAT or use the Inventor API. See the format doc for the full picture.

Requirements

.NET 10 SDK. The WinUI app additionally needs the Windows App SDK packages (restored automatically) and a Windows build target.