Convert JT to RFA in your application
3D InterOp is a CAD interoperability SDK that lets your software read JT 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 JT · Writes Revit family
- Mixed geometry → triangle mesh
- C++ / C# APIs
JT to RFA at a glance
JT can mix exact solids and facets; Revit family stores triangles only, so the whole model is tessellated when it is written.
| JT (source) | Revit family (target) | |
|---|---|---|
| Full name | Jupiter Tessellation | Revit family |
| Standard / owner | Siemens, ISO 14306 | Autodesk |
| File extensions | .jt | .rfa |
| Geometry | Tessellated and/or exact B-Rep | B-Rep and mesh (read); mesh (written by 3D InterOp) |
| Assemblies / structure | Yes | Nested families; assembly structure written by 3D InterOp |
| PMI | Semantic and graphical | None |
| 3D InterOp support | Read only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from JT to Revit family.
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Preserved
Product structureThe JT product structure is written to RFA.
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Changes
Geometry written as meshThe Revit writer writes mesh only: exact B-Rep from JT isn’t exported to the family.
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Not carried
PMIThe Revit writer writes no PMI, so the PMI read from JT isn’t written. Keep STEP AP242 as an output when PMI matters.
Why software vendors add JT 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 JT input: JT 8.x to 10.3 and 10.5 to 10.11.
- 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 a JT (.jt) file?
JT is Siemens’ lightweight format for visualizing and sharing 3D product data, published as ISO 14306. A JT file can hold tessellated levels of detail, exact B-Rep, product structure and PMI.
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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).
The Revit writer writes no PMI, so the PMI read from JT isn’t written. When PMI matters, offer STEP AP242 as an output.
Yes. 3D InterOp reads the JT product structure and writes it to RFA.
No. The Revit writer writes the geometry as mesh, in millimeters, without Revit parameters.
Yes. 3D InterOp imports several levels of detail and the visual materials of JT files.
3D InterOp reads JT 8.x to 10.3 and 10.5 to 10.11.
3D InterOp writes Revit 2026 families (.rfa).
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Building software that needs to convert JT to RFA?
3D InterOp is an SDK that lets your application read JT and write Revit family alongside 30+ CAD and BIM formats.