MBDInspector

A minimal WPF viewer for ISO 10303-21 STEP files (AP203, AP214, AP242 MBD).

Open a file, see the wireframe. That's it.

Features

• Open .stp / .step files via File → Open (Ctrl+O) or drag-and-drop
• Wireframe rendering with orbit / pan / zoom (mouse drag)
• File info panel: schema, edition, entity count, edge count, diagnostics
• Keyboard shortcuts: F fit all, Home reset camera

Rendering

Geometry is extracted from the parsed STEP entity graph using three strategies (in order):

1. EDGE_CURVE → vertex endpoints → CARTESIAN_POINT coordinates (full B-rep edge list)
2. POLY_LINE → connected point sequence
3. CARTESIAN_POINT cloud (no connectivity information)

Dependencies

Package	Purpose
StepParser	STEP tokenizer / lexer / parser (git submodule)
HelixToolkit.Wpf	3D viewport, orbit camera, line rendering

Build

git clone --recurse-submodules https://github.com/MinimalWindowsDev/MBDInspector
cd MBDInspector
$env:DOTNET_CLI_HOME="$PWD\.dotnet_home"
dotnet build MBDInspector.slnx

Requires the .NET 10 SDK and Windows.

License

GPL-3.0 — see LICENSE.