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For software developers · 3D InterOp SDK

Convert DWG to XCGM in your application

3D InterOp is a CAD interoperability SDK that lets your software read DWG files and write XCGM, carrying across the exact geometry the DWG file contains.

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 DWG · Writes XCGM
  • Mixed geometry → exact geometry
  • C++ / C# APIs
plan.dwgDWG · drawing sheets
Your application
3D InterOp SDK
DXF/DWG readerHealingXCGM writer
part.xcgmXCGM · exact B-Rep

DWG to XCGM at a glance

DWG can mix exact solids and facets; XCGM stores exact geometry. Exact elements are written as exact geometry, and elements stored only as facets stay faceted.

DWG (source)XCGM (target)
Full nameAutoCAD DrawingCGM native file
Standard / ownerAutodeskDassault Systèmes / Spatial (CGM Modeler)
File extensions.dwg.xcgm
Geometry2D drawings and 3D dataExact B-Rep
Assemblies / structureBlocks and layersYes
PMINoneSemantic (read)
3D InterOp supportRead; write drawings onlyRead and write

What's preserved, what changes

Here is what your application can expect to carry across from DWG to XCGM.

  • Preserved
    Exact geometry
    Exact B-Rep read from DWG is written to XCGM as exact geometry.

Why software vendors add DWG 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 DWG input: DXF/DWG 2.5 to 2027.
  • A DWG file that only contains 2D drawings has no 3D geometry to write.
  • 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 Study

About the formats

  • Source format

    What is a DWG (.dwg) file?

    DWG is the native file format of Autodesk AutoCAD, used for 2D drawings and 3D models. It is one of the most widespread formats for technical drawings.

  • 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

The exact B-Rep that 3D InterOp reads from DWG is written to XCGM; parts stored only as facets stay faceted.

No. PMI and miscellaneous data aren’t written to XCGM.

Then there is no 3D geometry to write to XCGM: 3D InterOp needs 3D content in the DWG 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 to AutoCAD users, write a neutral 3D format such as STEP.

3D InterOp reads DXF/DWG 2.5 to 2027.

3D InterOp writes R2012 to 2025 1.0.

  • Building software that needs to convert DWG to XCGM?

    3D InterOp is an SDK that lets your application read DWG and write XCGM alongside 30+ CAD and BIM formats.