Skip to content
For software developers · 3D InterOp SDK

Convert FBX to glTF in your application

3D InterOp is a CAD interoperability SDK that lets your software read FBX files and write glTF, carrying the mesh data across without re-tessellating it.

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 glTF
  • Triangle mesh → triangle mesh
  • C++ / C# APIs
scene.fbxFBX · mesh scene
Your application
3D InterOp SDK
FBX readerTessellationglTF writer
model.glbglTF 2.0 · web-ready mesh

FBX to glTF at a glance

Both formats store triangles, so the facets carry over without re-tessellation. The differences are in structure, appearance and metadata.

FBX (source)glTF (target)
Full nameFilmboxGL Transmission Format
Standard / ownerAutodeskKhronos Group
File extensions.fbx.gltf, .glb
GeometryTriangle meshTriangle mesh
Assemblies / structureYes: scene hierarchyYes: scene hierarchy
3D InterOp supportRead and writeWrite only

What's preserved, what changes

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

  • Preserved
    Mesh data
    The FBX facets are read and written to glTF without being re-tessellated.
  • Preserved
    Product structure
    The FBX product structure is written to glTF.
  • Improved
    Compressed meshes
    The glTF writer can compress meshes with Draco, available since 2026 1.0.1.

Why software vendors add FBX to glTF conversion

Lightweight review

glTF 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 glTF file gives them the shape in a format their tools can open.

Easier handling of large assemblies

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

Things to check before you ship

  • Written glTF versions: glTF 2.0 (.gltf or .glb).
  • The glTF writer is available through the UConnect interface only.
  • Supported FBX input: FBX 2.0 to 7.7 (mesh nodes).
  • 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 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 glTF (.gltf, .glb) file?

    glTF is the Khronos Group’s open format for delivering 3D content on the web and in real-time applications. It stores meshes, materials and the scene in a compact .gltf or binary .glb file.

Frequently asked questions

No re-tessellation is needed. 3D InterOp reads the FBX facets as visualization data and writes them to glTF.

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

Yes. Since 3D InterOp 2026 1.0.1, the glTF writer can compress meshes with Draco. It writes glTF 2.0 as .gltf or .glb.

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

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 glTF 2.0 (.gltf or .glb).

  • Building software that needs to convert FBX to glTF?

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