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For software developers · 3D InterOp SDK

Convert IFC to glTF in your application

3D InterOp is a CAD interoperability SDK that lets your software read IFC files and write glTF, generating the glTF 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 IFC · Writes glTF
  • Mixed geometry → triangle mesh
  • C++ / C# APIs
building.ifcIFC4 · BIM elements and properties
Your application
3D InterOp SDK
IFC readerTessellationglTF writer
model.glbglTF 2.0 · web-ready mesh

IFC to glTF at a glance

IFC can mix exact solids and facets; glTF stores triangles only, so the whole model is tessellated when it is written.

IFC (source)glTF (target)
Full nameIndustry Foundation ClassesGL Transmission Format
Standard / ownerbuildingSMART, ISO 16739Khronos Group
File extensions.ifc, .ifczip.gltf, .glb
GeometryExact B-Rep and tessellated geometryTriangle mesh
Assemblies / structureYes: spatial and element 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 IFC to glTF.

  • Preserved
    Product structure
    The IFC product structure is written to glTF.
  • Improved
    Compressed meshes
    The glTF writer can compress meshes with Draco, available since 2026 1.0.1.
  • Changes
    Geometry is tessellated
    The exact IFC 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.

Why software vendors add IFC 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 IFC input: IFC2x3 to IFC4x3 ADD2, from .ifc and .ifczip files.
  • 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 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.

  • 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

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

Yes. 3D InterOp reads the IFC 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.

3D InterOp reads IFC2x3 to IFC4x3 ADD2, from .ifc and .ifczip files.

3D InterOp writes glTF 2.0 (.gltf or .glb).

  • Building software that needs to convert IFC to glTF?

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