Convert NWD to CATIA V4 in your application
3D InterOp is a CAD interoperability SDK that lets your software read NWD files and write CATIA V4, 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 CATIA V4
- Mixed geometry → exact geometry
- C++ / C# APIs
NWD to CATIA V4 at a glance
Navisworks can mix exact solids and facets; CATIA V4 stores exact geometry. Exact elements are written as exact geometry, and elements stored only as facets stay faceted.
| Navisworks (source) | CATIA V4 (target) | |
|---|---|---|
| Full name | Navisworks document and cache files | CATIA Version 4 |
| Standard / owner | Autodesk | Dassault Systèmes |
| File extensions | .nwd, .nwc | .model, .exp, .session |
| Geometry | Mostly tessellated, B-Rep for cylinder and elliptical shapes | Exact B-Rep |
| Assemblies / structure | Yes | Yes (written as parts only) |
| 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 CATIA V4.
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Preserved
Exact geometryExact B-Rep read from NWD is written to CATIA V4 as exact geometry.
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Changes
Assembly flattenedThe CATIA V4 writer exports parts only: flatten the NWD assembly into a single body before export, or the .model file is empty.
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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 CATIA V4 conversion
Deliver in your customer’s CAD format
Aerospace and automotive OEMs often require supplier data in CATIA V4. Writing it lets your users meet that requirement directly from your application.
Exact geometry, ready to edit
CATIA V4 keeps exact B-Rep geometry, so the receiving engineer can measure, modify or machine the model in CATIA.
No neutral-format round trip
Writing CATIA V4 directly avoids an extra STEP or IGES step, and the loss each extra translation can add.
Things to check before you ship
- Written CATIA V4 versions: CATIA 4.1.9 to 4.2.4 (.model).
- The CATIA V4 writer isn’t available in 3D InterOp CGM.
- 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 a CATIA V4 (.model) file?
CATIA V4 is the legacy generation of Dassault Systèmes’ CATIA, whose models are mostly stored in .model files. Many aerospace and automotive archives still hold CATIA V4 data.
Frequently asked questions
The exact B-Rep that 3D InterOp reads from NWD is written to CATIA V4; parts stored only as facets stay faceted.
No. The CATIA V4 writer exports parts only: flatten the assembly into a single body before export, or the .model file is empty.
No. The CATIA V4 writer isn’t available in 3D InterOp CGM.
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 CATIA 4.1.9 to 4.2.4 (.model).
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 CATIA V4?
3D InterOp is an SDK that lets your application read Navisworks and write CATIA V4 alongside 30+ CAD and BIM formats.