Convert STL to VDA-FS in your application
3D InterOp is a CAD interoperability SDK that lets your software read STL files and write VDA-FS, writing the STL facets as faceted geometry, since STL 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 STL · Writes VDA-FS
- Triangle mesh → faceted B-Rep
- C++ / C# APIs
STL to VDA-FS at a glance
STL 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.
| STL (source) | VDA-FS (target) | |
|---|---|---|
| Full name | Stereolithography | VDA surface interface |
| Standard / owner | Open format | VDA (German automotive industry) |
| File extensions | .stl | .vda |
| Geometry | Triangle mesh | Exact curves and surfaces |
| Assemblies / structure | No | 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 STL to VDA-FS.
-
Changes
Faceted geometrySTL 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 STL 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 STL input: any STL version.
- 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 an STL file?
STL describes a 3D surface as a set of triangles, with no units, materials or assembly structure. Its simplicity makes it the usual input for 3D printing.
-
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. STL 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.
STL files store no units, so the 3D InterOp STL reader assumes millimeters. Agree on the unit with the application that wrote the file.
3D InterOp reads any STL version, as visualization data.
3D InterOp writes VDA-FS 2.0.
Yes. 3D InterOp reads and writes both formats, so VDA-FS to STL is supported too.
-
Building software that needs to convert STL to VDA-FS?
3D InterOp is an SDK that lets your application read STL and write VDA-FS alongside 30+ CAD and BIM formats.