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For software developers · 3D InterOp SDK

Convert XCGM to CGR in your application

3D InterOp is a CAD interoperability SDK that lets your software read XCGM files and write CGR, generating the CGR mesh from the geometry it reads, with tessellation settings your application controls.

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 XCGM · Writes CGR
  • Exact geometry → triangle mesh
  • C++ / C# APIs
part.xcgmXCGM · exact B-Rep
Your application
3D InterOp SDK
XCGM readerTessellationCATIA V5 writer
part.cgrCGR · tessellated

XCGM to CGR at a glance

XCGM stores exact geometry; CGR stores triangles. The translation is a tessellation, and the settings you choose decide how close the mesh stays to the original.

XCGM (source)CGR (target)
Full nameCGM native fileCATIA Graphical Representation
Standard / ownerDassault Systèmes / Spatial (CGM Modeler)Dassault Systèmes
File extensions.xcgm.cgr
GeometryExact B-RepTessellated geometry
Assemblies / structureYesSingle part
PMISemantic (read)None
3D InterOp supportRead and writeRead and write

What's preserved, what changes

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

  • Changes
    Geometry is tessellated
    The exact XCGM B-Rep is replaced by a triangle mesh, generated by 3D InterOp from the exact geometry it reads. Accuracy depends on the tessellation settings your application uses.
  • Changes
    Assembly structure
    CGR has no native assembly hierarchy. Decide in your application how XCGM product structure is grouped or flattened before writing.
  • Not carried
    PMI
    CGR has no place for PMI, so the PMI read from XCGM isn’t written.

Why software vendors add XCGM to CGR conversion

Lightweight review

CGR carries tessellated geometry that opens much faster than the full CAD model, so design reviews and digital mockups stay responsive.

Sharing outside engineering

Marketing, training and sales teams rarely have CAD software. A CGR file gives them the shape in a format their tools can open.

Easier handling of large assemblies

Without exact surfaces and feature data, CGR files are easier to transfer and display, even for large assemblies.

Things to check before you ship

  • Written CGR versions: CATIA V5 R15 to V5-6 R2026, with the CATIA V5 writer.
  • Supported XCGM input: R2012 to 2025 1.0.
  • Test tessellation settings on your heaviest parts: finer meshes mean larger files.
  • 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 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.

  • Target 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.

Frequently asked questions

3D InterOp tessellates the geometry it reads from XCGM when it writes CGR. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.

CGR has no place for PMI, so the PMI read from XCGM isn’t written. Your application can still access it after import, or offer STEP AP242 as an output.

CGR has no assembly hierarchy, so your application decides how the XCGM structure is grouped or flattened before writing.

3D InterOp reads R2012 to 2025 1.0.

3D InterOp writes CGR files with its CATIA V5 writer, for CATIA V5 R15 to V5-6 R2026.

Yes. 3D InterOp reads and writes both formats, so CGR to XCGM is supported too.

  • Building software that needs to convert XCGM to CGR?

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