Convert JT to CATIA V4 in your application
3D InterOp is a CAD interoperability SDK that lets your software read JT files and write CATIA V4, carrying across the exact geometry the JT 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 JT · Writes CATIA V4
- Mixed geometry → exact geometry
- C++ / C# APIs
JT to CATIA V4 at a glance
JT can mix exact solids and facets; CATIA V4 stores exact geometry. Exact elements are written as exact geometry, and elements stored only as facets stay faceted.
| JT (source) | CATIA V4 (target) | |
|---|---|---|
| Full name | Jupiter Tessellation | CATIA Version 4 |
| Standard / owner | Siemens, ISO 14306 | Dassault Systèmes |
| File extensions | .jt | .model, .exp, .session |
| Geometry | Tessellated and/or exact B-Rep | Exact B-Rep |
| Assemblies / structure | Yes | Yes (written as parts only) |
| PMI | Semantic and graphical | None in the format |
| 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 CATIA V4.
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Preserved
Exact geometryExact B-Rep read from JT is written to CATIA V4 as exact geometry.
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Changes
Assembly flattenedThe CATIA V4 writer exports parts only: flatten the JT assembly into a single body before export, or the .model file is empty.
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Changes
Faceted partsParts the JT file stores only as facets are written as facets.
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Not carried
PMICATIA V4 has 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 CATIA V4 conversion
Deliver in your customer’s CAD format
Aerospace and automotive OEMs often require supplier data in CATIA V4. Writing it lets your users meet that requirement directly from your application.
Exact geometry, ready to edit
CATIA V4 keeps exact B-Rep geometry, so the receiving engineer can measure, modify or machine the model in CATIA.
No neutral-format round trip
Writing CATIA V4 directly avoids an extra STEP or IGES step, and the loss each extra translation can add.
Things to check before you ship
- Written CATIA V4 versions: CATIA 4.1.9 to 4.2.4 (.model).
- The CATIA V4 writer isn’t available in 3D InterOp CGM.
- 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 a CATIA V4 (.model) file?
CATIA V4 is the legacy generation of Dassault Systèmes’ CATIA, whose models are mostly stored in .model files. Many aerospace and automotive archives still hold CATIA V4 data.
Frequently asked questions
The exact B-Rep that 3D InterOp reads from JT is written to CATIA V4; parts stored only as facets stay faceted.
CATIA V4 has no PMI, so the PMI read from JT isn’t written. When PMI matters, offer STEP AP242 as an output.
No. The CATIA V4 writer exports parts only: flatten the assembly into a single body before export, or the .model file is empty.
No. The CATIA V4 writer isn’t available in 3D InterOp CGM.
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 CATIA 4.1.9 to 4.2.4 (.model).
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Building software that needs to convert JT to CATIA V4?
3D InterOp is an SDK that lets your application read JT and write CATIA V4 alongside 30+ CAD and BIM formats.