Convert NWD to XCGM in your application
3D InterOp is a CAD interoperability SDK that lets your software read NWD files and write XCGM, carrying across the exact geometry the NWD file contains.
Spatial does not offer an online converter or a desktop conversion app. 3D InterOp is a component that software vendors embed in their own products.
- Reads Navisworks · Writes XCGM
- Mixed geometry → exact geometry
- C++ / C# APIs
NWD to XCGM at a glance
Navisworks can mix exact solids and facets; XCGM stores exact geometry. Exact elements are written as exact geometry, and elements stored only as facets stay faceted.
| Navisworks (source) | XCGM (target) | |
|---|---|---|
| Full name | Navisworks document and cache files | CGM native file |
| Standard / owner | Autodesk | Dassault Systèmes / Spatial (CGM Modeler) |
| File extensions | .nwd, .nwc | .xcgm |
| Geometry | Mostly tessellated, B-Rep for cylinder and elliptical shapes | Exact B-Rep |
| Assemblies / structure | Yes | Yes |
| PMI | Not imported by 3D InterOp | Semantic (read) |
| 3D InterOp support | Read only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from Navisworks to XCGM.
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Preserved
Exact geometryExact B-Rep read from NWD is written to XCGM as exact geometry.
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Changes
Mostly faceted modelNavisworks models are mainly read as visualization data; exact B-Rep is extracted only for cylinder and elliptical shapes.
Why software vendors add NWD to XCGM conversion
Hand models to kernel-based applications
Many CAD, CAM and CAE applications are built on the XCGM kernel. Writing XCGM gives them exact geometry they can load without another translation step.
Downstream modeling and analysis
An exact XCGM B-Rep can still be edited, meshed or machined by downstream tools, which a tessellated export would not allow.
Exchange within one ecosystem
Partners whose tools share the XCGM kernel often prefer to exchange XCGM files directly.
Things to check before you ship
- Written XCGM versions: R2012 to 2025 1.0.
- PMI and miscellaneous data aren’t written to XCGM.
- Supported NWD input: Navisworks 2011 to 2026 (.nwd and .nwc).
- Validate a sample of translated files in the target system your users actually work with.
Working with Spatial was a real milestone for us: Thanks to the powerful 3DInterOp library, we were able to successfully bring our complex CAD-based solutions to the cloud while remaining flexible to meet individual customer requirements. For us, Spatial is not just a technology partner, but a true enabler of our product strategy.
Dr. Arno Michelis, Founder, Simus Systems
Read the Case StudyAbout the formats
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Source format
What is a Navisworks (.nwd) file?
NWD is Autodesk Navisworks’ document format, a compact snapshot of a coordination model that combines files from many design tools. NWC files are the cache files Navisworks creates when it opens a native file.
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Target format
What is an XCGM (.xcgm) file?
XCGM is the native file format of the CGM geometric kernel, used by CGM Modeler and Dassault Systèmes applications. It stores exact B-Rep geometry.
Frequently asked questions
The exact B-Rep that 3D InterOp reads from NWD is written to XCGM; parts stored only as facets stay faceted.
No. PMI and miscellaneous data aren’t written to XCGM.
Mostly not. Navisworks models are read as visualization data; exact B-Rep is extracted only for cylinder and elliptical shapes.
3D InterOp reads Navisworks 2011 to 2026 (.nwd and .nwc).
3D InterOp writes R2012 to 2025 1.0.
No. 3D InterOp reads NWD but doesn’t write it. To send data back to Navisworks users, write a format Navisworks opens, such as IFC.
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Building software that needs to convert NWD to XCGM?
3D InterOp is an SDK that lets your application read Navisworks and write XCGM alongside 30+ CAD and BIM formats.