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For software developers · 3D InterOp SDK

Convert CGR to RFA in your application

3D InterOp is a CAD interoperability SDK that lets your software read CGR files and write RFA, writing a Revit family (.rfa) as mesh geometry.

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 CGR · Writes Revit family
  • Triangle mesh → triangle mesh
  • C++ / C# APIs
part.cgrCGR · tessellated
Your application
3D InterOp SDK
CATIA V5 readerHealingRevit writer
component.rfaRevit family · BIM component

CGR to RFA at a glance

Both formats store triangles, so the facets carry over without re-tessellation. The differences are in structure, appearance and metadata.

CGR (source)Revit family (target)
Full nameCATIA Graphical RepresentationRevit family
Standard / ownerDassault SystèmesAutodesk
File extensions.cgr.rfa
GeometryTessellated geometryB-Rep and mesh (read); mesh (written by 3D InterOp)
Assemblies / structureSingle partNested families; assembly structure written by 3D InterOp
3D InterOp supportRead and writeRead and write

What's preserved, what changes

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

  • Preserved
    Mesh data
    The CGR facets are read and written to RFA without being re-tessellated.
  • Changes
    Geometry written as mesh
    The Revit writer writes mesh only: exact B-Rep from CGR isn’t exported to the family.

Why software vendors add CGR to RFA conversion

Bring product content into Revit

Manufacturers publish their products as Revit families so architects can place them in building models. Writing RFA files lets your users produce that content from CAD data.

Coordinate with Revit-based teams

Many building projects are modeled in Revit. A Revit family gives those teams the geometry in a form they can load into their project.

Fewer manual remodeling steps

Without a direct export, CAD parts are often remodeled by hand in Revit. Writing the family directly saves your users that step.

Things to check before you ship

  • Written RFA versions: Revit 2026 families (.rfa).
  • Revit families are written in millimeters, without Revit parameters.
  • Supported CGR input: CATIA V5 R8 to V5-6 R2026.
  • 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 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.

  • Target format

    What is an RFA (.rfa) file?

    An RFA file is a Revit family: a reusable component such as a door, a window or a piece of equipment, with its geometry, types and parameters, loaded into Revit projects.

Frequently asked questions

No. The Revit writer writes mesh geometry only, without B-Rep or Revit parameters, for the latest Revit version (Revit 2026 in 3D InterOp 2026 1.0.1).

No. The Revit writer writes the geometry as mesh, in millimeters, without Revit parameters.

No. 3D InterOp reads CGR files directly, without CATIA or a CATIA license on the machine.

3D InterOp reads CATIA V5 R8 to V5-6 R2026, as visualization data.

3D InterOp writes Revit 2026 families (.rfa).

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

  • Building software that needs to convert CGR to RFA?

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