CAD data exchange

CAD Data Exchange Formats

Compare OCCT readers and writers with commercial CAD data exchange SDKs. Find import and export support for geometry, assemblies, metadata, meshes, BIM, and point clouds.

View all formats Find a conversion workflow

01Precise CAD geometry
02Assemblies and metadata
03Mesh, scene, and scan data

Integration model

Common OCCT representations for exchanged data

Interfaces convert to OCCT shapes or XCAF document structures and follow a common wrapper approach. The catalog combines formats available in the open-source distribution with added commercial translators.

For an application you can use directly, see CAD Assistant, the offline CAD viewer. The matrix below describes developer interfaces; available formats and export permissions in an end-user application depend on that application's package.

Complete catalog

Supported file formats

Showing all 23 formats

STEP.stp, .stepRead / WriteOpen Source

ISO 10303 BRep and mesh data, assemblies and attributes.

IGES.igs, .igesRead / WriteOpen Source

Established exchange format for CAD geometry.

XCAF.xbf, .xml, .ocfRead / WriteOpen Source

Native OCCT storage with assemblies and extended CAD attributes.

BREP.brep, .shapeRead / WriteOpen Source

Native boundary-representation geometry.

VRML.wrl, .vrmlRead / WriteOpen Source

Interactive 3D vector graphics.

STL.stlRead / WriteOpen Source

Triangulated geometry widely used for 3D printing.

PLY.plyNative write; Assimp readOpen Source

Native polygon writer; PLY reading is available through the commercial Assimp integration.

glTF.gltf, .glbRead / WriteOpen Source

Efficient delivery of 3D scenes and assets.

OBJ.objRead / WriteOpen Source

Wavefront polygonal geometry format.

JT SDK.jtRead / WriteCommercial

Mesh and assembly exchange; embedded Parasolid BRep import through the Parasolid interface.

Parasolid SDK.xt, .xb, .x_t, .x_bRead onlyCommercial

Siemens solid-modeling kernel format.

DXF SDK.dxfRead / WriteCommercial

Curves, BRep bodies and mesh data with read/write support.

ACIS SDK.sat, .sabRead / WriteCommercial

Spatial solid-modeling kernel format.

Assimp SDK.blend, .3ds, .3mf, .ac, .amf, .ase, .dae, .x3d, …Read onlyCommercial

Mesh, color, material and scene structure import.

USD SDK.usd, .usdz, .usdaRead / WriteCommercial

Meshes, primitives, names, hierarchy, colors, metadata, materials and animations.

FBX.fbxRead / WriteCommercial

Autodesk platform-independent 3D exchange.

RVM.rvmRead onlyCommercial

AVEVA PDMS Review Model for plant design.

STEP XML SDK.stpx, .stpa, .stpz, .stpzxRead / WriteCommercial

STEP XML BRep and mesh data, assemblies, names, colors and STEP attributes.

XPDMXML.xpdmxmlRead onlyCommercial

XML Product Data Management format.

MSC / NASTRAN.nasRead onlyCommercial

Finite-element analysis data.

IFC.ifcRead onlyCommercial

Industry Foundation Classes for BIM.

E57.e57Read onlyCommercial

Standard container for point-cloud data.

Point Cloud.ptx, .pts, .pslRead onlyCommercial

Common 3D scan and point-cloud formats.

CAD conversion workflows

Choose a reader, a representation and a writer

Browse individual source-to-target conversion guides for the supported CAD, scene, mesh, plant, BIM and scan inputs.

All supported input formats can feed mesh output through the appropriate preparation workflow. Tessellate BRep surfaces, reuse existing meshes, reconstruct surfaces from point clouds, and resolve referenced geometry for product-data inputs. Choose STL, OBJ, PLY, glTF, USD, JT, VRML or FBX for the receiving application.

STEP, STEP XML and DXF support mesh import and export as well as BRep workflows. Supported mesh readers and writers can be combined through OCCT; BRep surfaces can be tessellated for mesh destinations. Transferring a mesh into STEP preserves a mesh representation and does not reconstruct analytic surfaces.

Convert through OCCT shapes or an XDE document, using the reader and writer required by each format. A commercial importer can be combined with an open-source writer. Check geometry, units and attributes across the complete route.

STEP XML reading and writing

Read and write STPX, STPA, STPZ and STPZX files with assembly structure, names, colors and the native STEP attributes present in the data. Connect STEP XML to native STEP exchange workflows.

USD, USDZ and USDA scene exchange

Import and export meshes, primitives, names, hierarchy, colors, metadata, materials and animations. Define the scene representation required when preparing CAD data for USD delivery.

Mesh and scene import with Assimp

Read asset formats with their mesh geometry, colors, materials and structure. Use the imported scene for visualization or select a separate writer for a downstream conversion.

Parasolid X_T / X_B to STEP

Read Parasolid with the commercial import SDK and write STEP with OCCT. For STL or glTF / GLB output, prepare the tessellation needed by the target. This component does not export Parasolid.

STEP to JT and JT to STEP

Use the JT writer for assembly and mesh delivery. JT files containing Parasolid BRep can be imported through the Parasolid interface as precise OCCT shapes and exported to STEP. Mesh-only JT files use the mesh exchange route.

ACIS SAT / SAB and STEP

Combine ACIS exchange with OCCT's STEP reader or writer. Confirm import and export versions separately, including the ACIS version accepted by the receiving application.

DXF and STEP conversion

Identify the source entities and required output: curves, solid bodies or mesh representations. A file conversion alone does not generate a dimensioned drawing or turn 2D geometry into a designed 3D solid.

What must survive the conversion?

Specify exact geometry versus mesh, model units, hierarchy, names, colors and PMI. Preservation depends on the source data, the target format and the selected interfaces. Tessellation is a visualization representation; it does not retain the original CAD surfaces or feature history.

For a custom batch conversion pipeline, discuss CAD data exchange integration. For tessellation quality and throughput, explore Express Mesh. The OCCT documentation covers the open-source platform.

For graph-native healing, sewing, distance analysis and configurable meshing after import, explore BRepGraph Advance.

Additional bridges

Additional MCAD and AEC integrations

MCADCATIA, NX, Creo, SOLIDWORKS, Inventor, Solid Edge

AEC / BIMRevit, Navisworks, DWG

Native application bridges are separate from the format readers and writers above. Discuss the source application, version, licensing and integration requirements before selecting a bridge. Reading a Parasolid export does not imply direct support for the source application's native files.

Data exchange integration

Which product data must be preserved?

Specify the required geometry, hierarchy, appearance, PMI, and metadata before selecting readers and writers.

Discuss an exchange workflow Explore integration DevTools