Convert 3DXML to STP in your application
3D InterOp is a CAD interoperability SDK that lets your software read 3DXML files and write STP, writing the 3DXML facets as faceted geometry, since 3DXML 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 3D XML · Writes STEP
- Triangle mesh → faceted B-Rep
- C++ / C# APIs
3DXML to STP at a glance
3D XML stores triangles; STEP is an exact-geometry format. The mesh is written as faceted geometry: 3D InterOp doesn’t rebuild smooth surfaces from triangles.
| 3D XML (source) | STEP (target) | |
|---|---|---|
| Full name | 3D XML | Standard for the Exchange of Product model data |
| Standard / owner | Dassault Systèmes | ISO 10303 — AP203, AP214, AP242 |
| File extensions | .3dxml | .stp, .step |
| Geometry | Tessellated geometry | Exact B-Rep |
| Assemblies / structure | Yes | Yes |
| PMI | Graphical PMI | Graphical and semantic (AP242) |
| 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 3D XML to STEP.
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Preserved
Product structureThe 3DXML product structure is written to STP.
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Changes
Faceted geometry3DXML stores triangles, so the STP file holds faceted bodies, not solids. 3D InterOp doesn’t rebuild exact B-Rep from a mesh.
Why software vendors add 3DXML to STP conversion
Supplier and OEM exchange
STEP is the ISO standard most supply chains specify for exchanging 3D models. Writing it lets your users send data to partners on any CAD system.
Model-based definition
STEP AP242 can carry semantic PMI next to exact geometry, so your users can share models together with their manufacturing data.
Long-term archiving
As an ISO standard independent of any CAD vendor, STEP is widely used to archive product data.
Things to check before you ship
- Written STP versions: AP203, AP214 or AP242 (.stp, .step or .stpx).
- Supported 3DXML input: 3D XML 4.0 to 4.3 (tessellated data only).
- B-Rep stored in authoring-mode 3D XML files isn’t imported: only the tessellation is read.
- Test PMI transfer end to end with real 3DXML files from your users.
- 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 3D XML (.3dxml) file?
3D XML is Dassault Systèmes’ lightweight XML-based format for sharing 3D product data. 3D InterOp reads and writes its tessellated representation, with product structure and graphical PMI.
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Target format
What is a STEP (.stp) file?
STEP is the ISO 10303 standard for exchanging 3D product data between CAD systems. Its application protocols range from exact geometry (AP203, AP214) to full model-based definition with PMI (AP242).
Frequently asked questions
No. 3DXML stores triangles, and 3D InterOp writes them to STP as faceted geometry. It doesn’t rebuild exact B-Rep from a mesh.
3DXML carries graphical PMI. The STEP writer can write graphical PMI with views; test the result with your users’ files.
Yes. 3D InterOp reads the 3DXML product structure and writes it to STP.
The STEP writer supports AP203, AP214 and AP242, with AP214 as the default. Your application sets the version at export; semantic PMI is written to AP242 only.
No. B-Rep stored in authoring-mode 3D XML files isn’t imported: 3D InterOp reads the tessellation only.
3D InterOp reads 3D XML 4.0 to 4.3 (tessellated data only), as visualization data.
Yes. 3D InterOp reads and writes both formats, so STP to 3DXML is supported too.
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Building software that needs to convert 3DXML to STP?
3D InterOp is an SDK that lets your application read 3D XML and write STEP alongside 30+ CAD and BIM formats.