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For software developers · 3D InterOp SDK

Convert CATIA V4 to 3MF in your application

3D InterOp is a CAD interoperability SDK that lets your software read CATIA V4 files and write 3MF, generating the 3MF mesh from the geometry it reads, with tessellation settings your application controls, without a CATIA license.

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 CATIA V4 · Writes 3MF
  • Exact geometry → triangle mesh
  • C++ / C# APIs
part.modelCATIA V4 · exact B-Rep
Your application
3D InterOp SDK
CATIA V4 readerTessellation3MF writer
part.3mf3MF 1.1 · mesh with colors

CATIA V4 to 3MF at a glance

CATIA V4 stores exact geometry; 3MF stores triangles. The translation is a tessellation, and the settings you choose decide how close the mesh stays to the original.

CATIA V4 (source)3MF (target)
Full nameCATIA Version 43D Manufacturing Format
Standard / ownerDassault Systèmes3MF Consortium, ISO/IEC 25422
File extensions.model, .exp, .session.3mf
GeometryExact B-RepTriangle mesh
Assemblies / structureYes (written as parts only)Objects and build items
3D InterOp supportRead and writeRead and write

What's preserved, what changes

Here is what your application can expect to carry across from CATIA V4 to 3MF.

  • Changes
    Geometry is tessellated
    The exact CATIA V4 B-Rep is replaced by a triangle mesh, generated by 3D InterOp from the exact geometry it reads. Accuracy depends on the tessellation settings your application uses.
  • Changes
    Assembly structure
    3MF has no native assembly hierarchy. Decide in your application how CATIA V4 product structure is grouped or flattened before writing.

Why software vendors add CATIA V4 to 3MF conversion

Additive manufacturing

3MF is still the input most slicers and print services expect. Writing it lets your users send parts to print directly.

Mesh-based processing

Inspection, scan comparison and mesh-editing tools work on triangles. A mesh output gives them a model they can open anywhere.

Lightweight sharing

A mesh is simpler than the native CAD file and needs no CAD system to open.

Things to check before you ship

  • Written 3MF versions: 3MF 1.1.
  • The 3MF writer is available through the UConnect interface only.
  • Supported CATIA V4 input: CATIA 4.1.9 to 4.2.4 (.model, .exp, .session).
  • Test tessellation settings on your heaviest parts: finer meshes mean larger files.
  • 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 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.

  • Target format

    What is a 3MF (.3mf) file?

    3MF is an open format for additive manufacturing, defined by the 3MF Consortium. It stores triangle meshes with units, colors and build information in a single package.

Frequently asked questions

3D InterOp tessellates the geometry it reads from CATIA V4 when it writes 3MF. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.

3MF has no assembly hierarchy, so your application decides how the CATIA V4 structure is grouped or flattened before writing.

The 3MF writer is available through the 3D InterOp UConnect interface.

No. 3D InterOp reads CATIA V4 files directly, without CATIA or a CATIA license on the machine.

3D InterOp reads CATIA 4.1.9 to 4.2.4 (.model, .exp, .session).

3D InterOp writes 3MF 1.1.

Yes. 3D InterOp reads and writes both formats, so 3MF to CATIA V4 is supported too.

  • Building software that needs to convert CATIA V4 to 3MF?

    3D InterOp is an SDK that lets your application read CATIA V4 and write 3MF alongside 30+ CAD and BIM formats.