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For software developers · 3D InterOp SDK

Convert VDA-FS to CATProduct in your application

3D InterOp is a CAD interoperability SDK that lets your software read VDA-FS files and write CATProduct, with exact B-Rep geometry carried across and nothing tessellated.

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 VDA-FS · Writes CATProduct
  • Exact geometry → exact geometry
  • C++ / C# APIs
panel.vdaVDA-FS 2.0 · surfaces
Your application
3D InterOp SDK
VDA-FS readerHealingCATIA V5 writer
assembly.CATProductCATIA V5 assembly · product structure

VDA-FS to CATProduct at a glance

Both formats store exact geometry, so the model stays exact. The differences are in the product data each one can carry.

VDA-FS (source)CATProduct (target)
Full nameVDA surface interfaceCATIA V5 Product (assembly)
Standard / ownerVDA (German automotive industry)Dassault Systèmes
File extensions.vda.CATProduct
GeometryExact curves and surfacesExact B-Rep (in the referenced parts)
Assemblies / structureNo assembly hierarchyYes
PMINoneSemantic and graphical
3D InterOp supportRead and writeRead and write

What's preserved, what changes

Here is what your application can expect to carry across from VDA-FS to CATProduct.

  • Preserved
    Exact geometry
    Solids and surfaces stay exact B-Rep. The model is never reduced to a triangle mesh.

Why software vendors add VDA-FS 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 VDA-FS input: VDA-FS 1.0 to 2.0.
  • 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 VDA-FS (.vda) file?

    VDA-FS is a neutral surface-exchange format defined by the German automotive association VDA. It stores exact curves and free-form surfaces, and is still found in automotive supply chains.

  • 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

Yes. Both formats store exact B-Rep geometry, so the model is translated without being tessellated into triangles.

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

No. VDA-FS has no PMI, so only the geometry is translated to CATProduct.

3D InterOp reads VDA-FS 1.0 to 2.0.

3D InterOp writes CATIA V5 R15 to V5-6 R2026.

Yes. 3D InterOp reads and writes both formats, so CATProduct to VDA-FS is supported too.

  • Building software that needs to convert VDA-FS to CATProduct?

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