Skip to content
For software developers · 3D InterOp SDK

Convert Revit to CGR in your application

3D InterOp is a CAD interoperability SDK that lets your software read Revit 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 Revit · Writes CGR
  • Mixed geometry → triangle mesh
  • C++ / C# APIs
building.rvtRevit project · BIM model
Your application
3D InterOp SDK
Revit readerTessellationCATIA V5 writer
part.cgrCGR · tessellated

Revit to CGR at a glance

Revit can mix exact solids and facets; CGR stores triangles only, so the whole model is tessellated when it is written.

Revit (source)CGR (target)
Full nameAutodesk Revit projectCATIA Graphical Representation
Standard / ownerAutodeskDassault Systèmes
File extensions.rvt.cgr
GeometryB-Rep and meshTessellated geometry
Assemblies / structureYes: levels and building elementsSingle part
3D InterOp supportRead onlyRead and write

What's preserved, what changes

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

  • Changes
    Geometry is tessellated
    The exact Revit 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 Revit product structure is grouped or flattened before writing.

Why software vendors add Revit 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 Revit input: Revit 2015 to 2026.
  • 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 a Revit (.rvt) file?

    An RVT file is an Autodesk Revit project: the complete building model with its elements, levels, views and BIM properties.

  • 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 Revit when it writes CGR. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.

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

3D InterOp reads Revit 2015 to 2026.

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

No. 3D InterOp reads Revit but doesn’t write it. To send data back to Revit users, write IFC, or Revit families (.rfa) with 3D InterOp.

  • Building software that needs to convert Revit to CGR?

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