Convert DXF to CGR in your application
3D InterOp is a CAD interoperability SDK that lets your software read DXF files and write CGR, generating the CGR 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 DXF · Writes CGR
- Mixed geometry → triangle mesh
- C++ / C# APIs
DXF to CGR at a glance
DXF can mix exact solids and facets; CGR stores triangles only, so the whole model is tessellated when it is written.
| DXF (source) | CGR (target) | |
|---|---|---|
| Full name | Drawing Exchange Format | CATIA Graphical Representation |
| Standard / owner | Autodesk | Dassault Systèmes |
| File extensions | .dxf | .cgr |
| Geometry | 2D drawings and 3D data | Tessellated geometry |
| Assemblies / structure | Blocks and layers | Single part |
| 3D InterOp support | Read; write drawings only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from DXF to CGR.
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Changes
Geometry is tessellatedThe exact DXF 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 DXF 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 DXF input: DXF/DWG 2.5 to 2027.
- A DXF file that only contains 2D drawings has no 3D geometry to write.
- 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 DXF (.dxf) file?
DXF is Autodesk’s documented exchange format for AutoCAD drawings, mostly stored as text. Many CAD, CAM and cutting tools import it to exchange 2D geometry.
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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
3D InterOp tessellates the geometry it reads from DXF when it writes CGR. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.
Then there is no 3D geometry to write to CGR: 3D InterOp needs 3D content in the DXF file for this conversion.
Both the 2D content (drawing sheets) and the 3D data stored in the file.
No. 3D InterOp writes drawing sheets to DXF and DWG, but 3D export to these formats isn’t supported. To send 3D data back, write a neutral 3D format such as STEP.
3D InterOp reads DXF/DWG 2.5 to 2027.
3D InterOp writes CGR files with its CATIA V5 writer, for CATIA V5 R15 to V5-6 R2026.
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Building software that needs to convert DXF to CGR?
3D InterOp is an SDK that lets your application read DXF and write CGR alongside 30+ CAD and BIM formats.