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For software developers · 3D InterOp SDK

Convert Parasolid to CATPart in your application

3D InterOp is a CAD interoperability SDK that lets your software read Parasolid files and write CATPart, with exact B-Rep geometry carried across and nothing tessellated.

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 Parasolid · Writes CATPart
  • Exact geometry → exact geometry
  • C++ / C# APIs
bracket.x_tParasolid · exact B-Rep
Your application
3D InterOp SDK
Parasolid readerHealingCATIA V5 writer
bracket.CATPartCATIA V5 part · exact B-Rep · PMI

Parasolid to CATPart at a glance

Both formats store exact geometry, so the model stays exact. The differences are in the product data each one can carry.

Parasolid (source)CATPart (target)
Full nameParasolid transmit file (text X_T, binary X_B)CATIA V5 Part
Standard / ownerProprietary — SiemensDassault Systèmes
File extensions.x_t, .x_b, .xmt_txt, .xmt_bin.CATPart
GeometryExact B-RepExact B-Rep
Assemblies / structureYes (Parasolid assembly structure)Part file (assemblies are CATProduct files)
PMIPMI groups and attributes (3D InterOp representation)Semantic and graphical
3D InterOp supportRead and write · up to Parasolid 38Read and write

What's preserved, what changes

Here is what your application can expect to carry across from Parasolid to CATPart.

  • Preserved
    Exact geometry
    Solids and surfaces stay exact B-Rep. The model is never reduced to a triangle mesh.
  • Changes
    Assembly structure
    CATPart has no native assembly hierarchy. Decide in your application how Parasolid product structure is grouped or flattened before writing.

Why software vendors add Parasolid to CATPart conversion

Deliver in your customer’s CAD format

Aerospace and automotive OEMs often require supplier data in CATPart. Writing it lets your users meet that requirement directly from your application.

Exact geometry, ready to edit

CATPart keeps exact B-Rep geometry, so the receiving engineer can measure, modify or machine the model in CATIA.

No neutral-format round trip

Writing CATPart directly avoids an extra STEP or IGES step, and the loss each extra translation can add.

Things to check before you ship

  • Written CATPart versions: CATIA V5 R15 to V5-6 R2026.
  • Supported Parasolid input: Parasolid 9.0 to 38.0.
  • 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 Parasolid (X_T) file?

    Parasolid is the geometric modeling kernel developed by Siemens and used by many CAD, CAM and CAE applications. Its transmit files store exact B-Rep models as text (.x_t) or binary (.x_b).

  • Target format

    What is a CATPart (.CATPart) file?

    A CATPart file is a CATIA V5 part: one component with its exact 3D geometry, features and, often, PMI. Assemblies of parts are stored in CATProduct files.

Frequently asked questions

Yes. Both formats store exact B-Rep geometry, so the model is translated without being tessellated into triangles.

Yes. 3D InterOp reads Parasolid text (.x_t, .xmt_txt) and binary (.x_b, .xmt_bin) files.

3D InterOp reads Parasolid 9.0 to 38.0.

3D InterOp writes CATIA V5 R15 to V5-6 R2026.

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

  • Building software that needs to convert Parasolid to CATPart?

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