Convert CGR to glTF in your application
3D InterOp is a CAD interoperability SDK that lets your software read CGR files and write glTF, carrying the mesh data across without re-tessellating it, without a CATIA license.
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 CGR · Writes glTF
- Triangle mesh → triangle mesh
- C++ / C# APIs
CGR 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.
| CGR (source) | glTF (target) | |
|---|---|---|
| Full name | CATIA Graphical Representation | GL Transmission Format |
| Standard / owner | Dassault Systèmes | Khronos Group |
| File extensions | .cgr | .gltf, .glb |
| Geometry | Tessellated geometry | Triangle mesh |
| Assemblies / structure | Single part | Yes: scene hierarchy |
| 3D InterOp support | Read and write | Write only |
What's preserved, what changes
Here is what your application can expect to carry across from CGR to glTF.
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Preserved
Mesh dataThe CGR facets are read and written to glTF without being re-tessellated.
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Improved
Compressed meshesThe glTF writer can compress meshes with Draco, available since 2026 1.0.1.
Why software vendors add CGR 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 CGR input: CATIA V5 R8 to V5-6 R2026.
- 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 StudyAbout the formats
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Source format
What is a CGR (.cgr) file?
CGR is CATIA’s lightweight graphical representation format. It stores a tessellated version of a part for fast display in large assemblies.
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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 CGR facets as visualization data and writes them 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.
No. 3D InterOp reads CGR files directly, without CATIA or a CATIA license on the machine.
3D InterOp reads CATIA V5 R8 to V5-6 R2026, as visualization data.
3D InterOp writes glTF 2.0 (.gltf or .glb).
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Building software that needs to convert CGR to glTF?
3D InterOp is an SDK that lets your application read CGR and write glTF alongside 30+ CAD and BIM formats.