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For software developers · 3D InterOp SDK

Convert XCGM to FBX in your application

3D InterOp is a CAD interoperability SDK that lets your software read XCGM files and write FBX, generating the FBX mesh from the geometry it reads, with tessellation settings your application controls.

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 XCGM · Writes FBX
  • Exact geometry → triangle mesh
  • C++ / C# APIs
part.xcgmXCGM · exact B-Rep
Your application
3D InterOp SDK
XCGM readerTessellationFBX writer
scene.fbxFBX · mesh scene

XCGM to FBX at a glance

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

XCGM (source)FBX (target)
Full nameCGM native fileFilmbox
Standard / ownerDassault Systèmes / Spatial (CGM Modeler)Autodesk
File extensions.xcgm.fbx
GeometryExact B-RepTriangle mesh
Assemblies / structureYesYes: scene hierarchy
PMISemantic (read)None
3D InterOp supportRead and writeRead and write

What's preserved, what changes

Here is what your application can expect to carry across from XCGM to FBX.

  • Changes
    Geometry is tessellated
    The exact XCGM 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.
  • Not carried
    PMI
    FBX has no place for PMI, so the PMI read from XCGM isn’t written.

Why software vendors add XCGM to FBX conversion

Lightweight review

FBX carries tessellated geometry that opens much faster than the full CAD model, so design reviews and digital mockups stay responsive.

Sharing outside engineering

Marketing, training and sales teams rarely have CAD software. A FBX file gives them the shape in a format their tools can open.

Easier handling of large assemblies

Without exact surfaces and feature data, FBX files are easier to transfer and display, even for large assemblies.

Things to check before you ship

  • Written FBX versions: FBX 7.7.0.
  • Points and wires aren’t written to FBX.
  • The FBX writer is available through the UConnect interface only.
  • Supported XCGM input: R2012 to 2025 1.0.
  • 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 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.

  • Target format

    What is an FBX (.fbx) file?

    FBX is Autodesk’s format for exchanging 3D scenes between content-creation, game and real-time tools. It stores meshes, materials and the scene hierarchy.

Frequently asked questions

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

FBX has no place for PMI, so the PMI read from XCGM isn’t written. Your application can still access it after import, or offer STEP AP242 as an output.

No. The FBX writer writes meshes; points and wires from the source aren’t written.

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

3D InterOp reads R2012 to 2025 1.0.

3D InterOp writes FBX 7.7.0.

Yes. 3D InterOp reads and writes both formats, so FBX to XCGM is supported too.

  • Building software that needs to convert XCGM to FBX?

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