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For software developers · 3D InterOp SDK

Convert FBX to Parasolid in your application

3D InterOp is a CAD interoperability SDK that lets your software read FBX files and write Parasolid, writing the FBX facets as faceted geometry, since FBX stores triangles rather than solids.

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 FBX · Writes Parasolid
  • Triangle mesh → faceted B-Rep
  • C++ / C# APIs
scene.fbxFBX · mesh scene
Your application
3D InterOp SDK
FBX readerHealingParasolid writer
bracket.x_tParasolid · exact B-Rep

FBX to Parasolid at a glance

FBX stores triangles; Parasolid is an exact-geometry format. The mesh is written as faceted geometry: 3D InterOp doesn’t rebuild smooth surfaces from triangles.

FBX (source)Parasolid (target)
Full nameFilmboxParasolid transmit file (text X_T, binary X_B)
Standard / ownerAutodeskProprietary — Siemens
File extensions.fbx.x_t, .x_b, .xmt_txt, .xmt_bin
GeometryTriangle meshExact B-Rep
Assemblies / structureYes: scene hierarchyYes (Parasolid assembly structure)
3D InterOp supportRead and writeRead and write · up to Parasolid 38

What's preserved, what changes

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

  • Changes
    Faceted geometry
    FBX stores triangles, so the Parasolid file holds faceted bodies, not solids. 3D InterOp doesn’t rebuild exact B-Rep from a mesh.

Why software vendors add FBX to Parasolid conversion

Hand models to kernel-based applications

Many CAD, CAM and CAE applications are built on the Parasolid kernel. Writing Parasolid gives them exact geometry they can load without another translation step.

Downstream modeling and analysis

An exact Parasolid B-Rep can still be edited, meshed or machined by downstream tools, which a tessellated export would not allow.

Exchange within one ecosystem

Partners whose tools share the Parasolid kernel often prefer to exchange Parasolid files directly.

Things to check before you ship

  • Written Parasolid versions: Parasolid 12 to 38.0.150.
  • Writing Parasolid needs a Parasolid installation: there is no Parasolid Direct writer.
  • Supported FBX input: FBX 2.0 to 7.7 (mesh nodes).
  • 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 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.

  • Target format

    What is a Parasolid (X_T) file?

    Parasolid is the geometric modeling kernel developed by Siemens and used by many CAD, CAM and CAE applications. Its transmit files store exact B-Rep models as text (.x_t) or binary (.x_b).

Frequently asked questions

No. FBX stores triangles, and 3D InterOp writes them to Parasolid as faceted geometry. It doesn’t rebuild exact B-Rep from a mesh.

Parasolid has no assembly hierarchy, so your application decides how the FBX structure is grouped or flattened before writing.

Yes. Writing Parasolid needs a Parasolid installation: there is no Parasolid Direct writer.

Yes, when the folder of the FBX file is writable. 3D InterOp also reads the visual material properties.

3D InterOp reads FBX 2.0 to 7.7 (mesh nodes), as visualization data.

3D InterOp writes Parasolid 12 to 38.0.150.

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

  • Building software that needs to convert FBX to Parasolid?

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