STEP Importer

Bring CAD models into Unity – from SolidWorks, CATIA or any other CAD system that exports STEP.

Drag a .step or .stp file into your project just as you would with an fbx. Complete assembly structure, names, colors and correctly scaled, watertight meshes. Or load STEP files at runtime with a single line of code. Tested on PC, Android and WebGL - should work for any other platform, too.

100% C#, NO NATIVE PLUGINS

STEP Importer is written entirely in C#. No native DLLs, no external CAD kernel and no third-party licenses – it is not tied to Windows and is easy to ship with your application. Full source code is included.

HIGH-QUALITY TESSELLATION

The exact CAD geometry (B-rep) is converted to triangles with adjustable quality.

EDITOR IMPORT

- Quality presets (Low to Very High) or custom tolerances

- Import report with statistics and warnings

- Extract and remap materials, generate lightmap UVs, add mesh colliders

- Progress bar with cancel for large files

RUNTIME LOADING

- GameObject model = await StepLoader.LoadAsync(path);

- Loading from files, memory or URLs, with progress and cancellation

- Reading and tessellation run on background threads, objects are created over several frames – your app stays responsive

- Destroying the model frees all its meshes and materials automatically

- STEP Model Loader component: load files without writing code

VALIDATED WITH REAL CAD DATA

Tested with the public NIST CAD test models (AP203 and AP242 exports from CATIA, NX, Creo and SolidWorks) and real-world parts, assemblies and city models.

Ideal for digital twins, industrial and product visualization, configurators, AR/VR training, simulation and engineering tools.

Note: STEP Importer reads STEP files. Native CAD formats (e.g. .sldprt, .catpart) can be exported as STEP from the CAD system. Product manufacturing information (dimensions, tolerances) is not displayed.