Convert CGR to VDA-FS in your application
3D InterOp is a CAD interoperability SDK that lets your software read CGR files and write VDA-FS, writing the CGR facets as faceted geometry, since CGR stores triangles rather than solids.
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 VDA-FS
- Triangle mesh → faceted B-Rep
- C++ / C# APIs
CGR to VDA-FS at a glance
CGR stores triangles; VDA-FS is an exact-geometry format. The mesh is written as faceted geometry: 3D InterOp doesn’t rebuild smooth surfaces from triangles.
| CGR (source) | VDA-FS (target) | |
|---|---|---|
| Full name | CATIA Graphical Representation | VDA surface interface |
| Standard / owner | Dassault Systèmes | VDA (German automotive industry) |
| File extensions | .cgr | .vda |
| Geometry | Tessellated geometry | Exact curves and surfaces |
| Assemblies / structure | Single part | No assembly hierarchy |
| 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 CGR to VDA-FS.
-
Changes
Faceted geometryCGR stores triangles, so the VDA-FS file holds faceted bodies, not solids. 3D InterOp doesn’t rebuild exact B-Rep from a mesh.
Why software vendors add CGR to VDA-FS conversion
Legacy CAD and CAM systems
Many established engineering tools still consume VDA-FS first. Writing it lets your users hand data to them without leaving your application.
Supplier and partner exchange
Some suppliers and manufacturing partners still specify VDA-FS in their exchange requirements. Your software can meet them directly.
Geometry-only workflows
When a downstream process needs exact part geometry and nothing more, VDA-FS is a simple, widely readable target.
Things to check before you ship
- Written VDA-FS versions: VDA-FS 2.0.
- The VDA-FS writer isn’t available in 3D InterOp CGM.
- Supported CGR input: CATIA V5 R8 to V5-6 R2026.
- 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 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.
-
Target format
What is a VDA-FS (.vda) file?
VDA-FS is a neutral surface-exchange format defined by the German automotive association VDA. It stores exact curves and free-form surfaces, and is still found in automotive supply chains.
Frequently asked questions
No. CGR stores triangles, and 3D InterOp writes them to VDA-FS as faceted geometry. It doesn’t rebuild exact B-Rep from a mesh.
No. The VDA-FS writer isn’t available in 3D InterOp CGM.
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 VDA-FS 2.0.
Yes. 3D InterOp reads and writes both formats, so VDA-FS to CGR is supported too.
-
Building software that needs to convert CGR to VDA-FS?
3D InterOp is an SDK that lets your application read CGR and write VDA-FS alongside 30+ CAD and BIM formats.