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For software developers · 3D InterOp SDK

Convert FBX to IFC in your application

3D InterOp is a CAD interoperability SDK that lets your software read FBX files and write IFC, 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 IFC
  • Triangle mesh → faceted model
  • C++ / C# APIs
scene.fbxFBX · mesh scene
Your application
3D InterOp SDK
FBX readerHealingIFC writer
building.ifcIFC4 · BIM elements and properties

FBX to IFC at a glance

FBX stores triangles; IFC can hold facets alongside exact solids, so the mesh is written as faceted geometry.

FBX (source)IFC (target)
Full nameFilmboxIndustry Foundation Classes
Standard / ownerAutodeskbuildingSMART, ISO 16739
File extensions.fbx.ifc, .ifczip
GeometryTriangle meshExact B-Rep and tessellated geometry
Assemblies / structureYes: scene hierarchyYes: spatial and element hierarchy
3D InterOp supportRead and writeRead and write

What's preserved, what changes

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

  • Preserved
    Product structure
    The FBX product structure is written to IFC.
  • Changes
    Faceted geometry
    FBX stores triangles, so the IFC file holds faceted bodies, not solids. 3D InterOp doesn’t rebuild exact B-Rep from a mesh.

Why software vendors add FBX to IFC conversion

Open BIM deliverables

Many projects specify IFC deliverables. Writing it lets your users meet those requirements from your software.

Coordination and clash detection

Coordination tools gather models from every discipline in IFC. Your users can contribute without a round trip through another tool.

Facility and asset data

Owners and operators often receive building data as IFC for asset management after handover.

Things to check before you ship

  • Written IFC versions: IFC2x3 to IFC4x3 ADD2 (.ifc).
  • Exact B-Rep needs IFC4 or later; IFC2x3 files only get tessellation.
  • FBX has no BIM semantics: check which IFC class your application assigns to each object.
  • 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 an IFC (.ifc) file?

    IFC is the open, vendor-neutral standard for exchanging building information models, maintained by buildingSMART and published as ISO 16739. It carries building elements with their geometry, properties and relationships.

Frequently asked questions

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

Yes. 3D InterOp reads the FBX product structure and writes it to IFC.

Write IFC4 or later to keep exact B-Rep: IFC2x3 files only get tessellation. 3D InterOp writes IFC2x3 to IFC4x3 ADD2.

FBX has no BIM semantics, so your application decides which IFC class each object is written as.

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 IFC2x3 to IFC4x3 ADD2 (.ifc).

  • Building software that needs to convert FBX to IFC?

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