Convert 3MF to CGR in your application
3D InterOp is a CAD interoperability SDK that lets your software read 3MF files and write CGR, 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 3MF · Writes CGR
- Triangle mesh → triangle mesh
- C++ / C# APIs
3MF to CGR at a glance
Both formats store triangles, so the facets carry over without re-tessellation. The differences are in structure, appearance and metadata.
| 3MF (source) | CGR (target) | |
|---|---|---|
| Full name | 3D Manufacturing Format | CATIA Graphical Representation |
| Standard / owner | 3MF Consortium, ISO/IEC 25422 | Dassault Systèmes |
| File extensions | .3mf | .cgr |
| Geometry | Triangle mesh | Tessellated geometry |
| Assemblies / structure | Objects and build items | Single part |
| 3D InterOp support | Read and write | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from 3MF to CGR.
-
Preserved
Mesh dataThe 3MF facets are read and written to CGR without being re-tessellated.
Why software vendors add 3MF to CGR conversion
Lightweight review
CGR 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 CGR file gives them the shape in a format their tools can open.
Easier handling of large assemblies
Without exact surfaces and feature data, CGR files are easier to transfer and display, even for large assemblies.
Things to check before you ship
- Written CGR versions: CATIA V5 R15 to V5-6 R2026, with the CATIA V5 writer.
- Supported 3MF input: 3MF 1.1.
- 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
-
Source format
What is a 3MF (.3mf) file?
3MF is an open format for additive manufacturing, defined by the 3MF Consortium. It stores triangle meshes with units, colors and build information in a single package.
-
Target 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.
Frequently asked questions
No re-tessellation is needed. 3D InterOp reads the 3MF facets as visualization data and writes them to CGR.
Per-facet colors are imported. Textures and materials aren’t.
3D InterOp reads 3MF 1.1, as visualization data.
3D InterOp writes CGR files with its CATIA V5 writer, for CATIA V5 R15 to V5-6 R2026.
Yes. 3D InterOp reads and writes both formats, so CGR to 3MF is supported too.
-
Building software that needs to convert 3MF to CGR?
3D InterOp is an SDK that lets your application read 3MF and write CGR alongside 30+ CAD and BIM formats.