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For software developers · 3D InterOp SDK

Convert NWD to CATProduct in your application

3D InterOp is a CAD interoperability SDK that lets your software read NWD files and write CATProduct, 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 CATProduct
  • Mixed geometry → exact geometry
  • C++ / C# APIs
project.nwdNavisworks · coordination model
Your application
3D InterOp SDK
Navisworks readerHealingCATIA V5 writer
assembly.CATProductCATIA V5 assembly · product structure

NWD to CATProduct at a glance

Navisworks can mix exact solids and facets; CATProduct stores exact geometry. Exact elements are written as exact geometry, and elements stored only as facets stay faceted.

Navisworks (source)CATProduct (target)
Full nameNavisworks document and cache filesCATIA V5 Product (assembly)
Standard / ownerAutodeskDassault Systèmes
File extensions.nwd, .nwc.CATProduct
GeometryMostly tessellated, B-Rep for cylinder and elliptical shapesExact B-Rep (in the referenced parts)
Assemblies / structureYesYes
PMINot imported by 3D InterOpSemantic and graphical
3D InterOp supportRead onlyRead and write

What's preserved, what changes

Here is what your application can expect to carry across from Navisworks to CATProduct.

  • Preserved
    Exact geometry
    Exact B-Rep read from NWD is written to CATProduct as exact geometry.
  • Preserved
    Product structure
    The NWD product structure is written to CATProduct.
  • Changes
    Mostly faceted model
    Navisworks models are mainly read as visualization data; exact B-Rep is extracted only for cylinder and elliptical shapes.

Why software vendors add NWD to CATProduct conversion

Deliver in your customer’s CAD format

Aerospace and automotive OEMs often require supplier data in CATProduct. Writing it lets your users meet that requirement directly from your application.

Exact geometry, ready to edit

CATProduct keeps exact B-Rep geometry, so the receiving engineer can measure, modify or machine the model in CATIA.

No neutral-format round trip

Writing CATProduct directly avoids an extra STEP or IGES step, and the loss each extra translation can add.

Things to check before you ship

  • Written CATProduct versions: CATIA V5 R15 to V5-6 R2026.
  • A CATProduct written by 3D InterOp can’t reference files in other formats.
  • 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 Study

About the formats

  • 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.

  • Target format

    What is a CATProduct (.CATProduct) file?

    A CATProduct file is a CATIA V5 assembly. It defines the product structure and positions, and references the CATPart files that hold the geometry.

Frequently asked questions

The exact B-Rep that 3D InterOp reads from NWD is written to CATProduct; parts stored only as facets stay faceted.

Yes. 3D InterOp reads the NWD product structure and writes it to CATProduct.

No. A CATProduct written by 3D InterOp can’t reference files in other formats.

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 V5 R15 to V5-6 R2026.

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.

  • Building software that needs to convert NWD to CATProduct?

    3D InterOp is an SDK that lets your application read Navisworks and write CATProduct alongside 30+ CAD and BIM formats.