Convert SLDASM to XCGM in your application
3D InterOp is a CAD interoperability SDK that lets your software read SLDASM files and write XCGM, with exact B-Rep geometry carried across and nothing tessellated.
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 SOLIDWORKS assembly · Writes XCGM
- Exact geometry → exact geometry
- C++ / C# APIs
SLDASM to XCGM at a glance
Both formats store exact geometry, so the model stays exact. The differences are in the product data each one can carry.
| SOLIDWORKS assembly (source) | XCGM (target) | |
|---|---|---|
| Full name | SOLIDWORKS Assembly | CGM native file |
| Standard / owner | Dassault Systèmes SOLIDWORKS | Dassault Systèmes / Spatial (CGM Modeler) |
| File extensions | .sldasm | .xcgm |
| Geometry | Exact B-Rep (in the referenced parts) | Exact B-Rep |
| Assemblies / structure | Yes | Yes |
| PMI | Semantic (DimXpert) and graphical, SOLIDWORKS 2014 and later | Semantic (read) |
| 3D InterOp support | Read only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from SOLIDWORKS assembly to XCGM.
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Preserved
Exact geometrySolids and surfaces stay exact B-Rep. The model is never reduced to a triangle mesh.
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Not carried
PMI3D InterOp doesn’t write PMI to XCGM, so the PMI read from SLDASM isn’t written. Keep STEP AP242 as an output when PMI matters.
Why software vendors add SLDASM to XCGM conversion
Hand models to kernel-based applications
Many CAD, CAM and CAE applications are built on the XCGM kernel. Writing XCGM gives them exact geometry they can load without another translation step.
Downstream modeling and analysis
An exact XCGM B-Rep can still be edited, meshed or machined by downstream tools, which a tessellated export would not allow.
Exchange within one ecosystem
Partners whose tools share the XCGM kernel often prefer to exchange XCGM files directly.
Things to check before you ship
- Written XCGM versions: R2012 to 2025 1.0.
- PMI and miscellaneous data aren’t written to XCGM.
- Supported SLDASM input: SOLIDWORKS 98 to 2026.
- 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 an SLDASM (.sldasm) file?
An SLDASM file is a SOLIDWORKS assembly. It defines how parts and sub-assemblies fit together and references the SLDPRT files that hold their geometry.
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Target format
What is an XCGM (.xcgm) file?
XCGM is the native file format of the CGM geometric kernel, used by CGM Modeler and Dassault Systèmes applications. It stores exact B-Rep geometry.
Frequently asked questions
Yes. Both formats store exact B-Rep geometry, so the model is translated without being tessellated into triangles.
3D InterOp doesn’t write PMI to XCGM, so the PMI read from SLDASM isn’t written. When PMI matters, offer STEP AP242 as an output.
No. PMI and miscellaneous data aren’t written to XCGM.
Yes. If your application uses Parasolid, a Parasolid-based SOLIDWORKS reader is available.
Semantic PMI from SOLIDWORKS 2014 to 2026, and graphical PMI from SOLIDWORKS 2014 onwards.
3D InterOp reads SOLIDWORKS 98 to 2026.
3D InterOp writes R2012 to 2025 1.0.
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Building software that needs to convert SLDASM to XCGM?
3D InterOp is an SDK that lets your application read SOLIDWORKS assembly and write XCGM alongside 30+ CAD and BIM formats.