STEP Writer

The STEP writer allows developers to export B-rep data from Exchange to STEP. The file extensions that you can create when you export the data are:

  • .STEP

  • .STP

  • .STPZ (_AP242_ only)

To compress a STEP file, simply use the .STPZ file extension appended to the file name in the export file name parameter for

the A3DAsmModelFileExportToStepFile() function.

Assembly

The full assembly tree is exported with all the instancing information maintained.

B-Rep

When we export to STEP we look at the source data and map each surface to one of the following:

  • B_SPLINE_SURFACE

  • B_SPLINE_SURFACE_WITH_KNOTS

  • CONICAL_SURFACE

  • CYLINDRICAL_SURFACE

  • DEGENERATE_TOROIDAL_SURFACE

  • OFFSET_SURFACE

  • RATIONAL_B_SPLINE_SURFACE

  • RECTANGULAR_TRIMMED_SURFACE

  • SPHERICAL_SURFACE

  • SURFACE_OF_REVOLUTION

  • TOROIDAL_SURFACE

…and curves to one of the following:

  • B_SPLINE_CURVE

  • B_SPLINE_CURVE_WITH_KNOTS

  • CIRCLE

  • COMPOSITE_CURVE

  • POLYLINE

  • RATIONAL_B_SPLINE_CURVE

Our STEP writer supports the export of tessellated geometry to the AP242 format. This includes tessellated solids, shells, wires, and point sets.

Tessellation

HOOPS Exchange only export tessellated data from import files originally containing only tessellation data. As such, to write to tessellated STEP, your originating file needs to have been imported with A3DRWParamsGeneralData.m_eReadGeomTessMode set to kA3DReadTessOnly.

Visualization

Our STEP writer supports the export of tessellated geometry to the AP242 format. This includes tessellated solids, shells, wires, and point sets.

If a part contains solids with no B-rep, all of the geometry for this part will be exported as tessellated geometry for the AP242 format. This includes TESSELLATED_SOLID, TESSELLATED_SHELL, TESSELLATED_WIRE, and TESSELLATED_POINT_SET.

Writing B-rep and tessellation together is not yet supported.

Views

Views, camera definitions, sections, and PMI visibility are supported by our STEP file writer.

PMI

PMI is supported by our STEP file writer. HOOPS Exchange supports export of semantic PMI to the STEP AP242 format.

This includes:

  • DIMENSIONAL_SIZE

  • DIMENSIONAL_LOCATION

  • POSITION_TOLERANCE

  • STRAIGHTNESS_TOLERANCE

  • UNEQUALLY_DISPOSED_GEOMETRIC_TOLERANCE

  • GEOMETRIC_TOLERANCE_WITH_DEFINED_UNIT

  • GEOMETRIC_TOLERANCE_WITH_DEFINED_AREA_UNIT

  • GEOMETRIC_TOLERANCE_WITH_MODIFIERS

  • GEOMETRIC_TOLERANCE_WITH_MAXIMUM_TOLERANCE

  • MODIFIED_GEOMETRIC_TOLERANCE

  • CYLINDRICITY_TOLERANCE

  • FLATNESS_TOLERANCE

  • LINE_PROFILE_TOLERANCE

  • ROUNDNESS_TOLERANCE

  • SURFACE_PROFILE_TOLERANCE

  • GEOMETRIC_TOLERANCE_WITH_DATUM_REFERENCE

  • COAXIALITY_TOLERANCE

  • CONCENTRICITY_TOLERANCE

  • CIRCULAR_RUNOUT_TOLERANCE

  • TOTAL_RUNOUT_TOLERANCE

  • ANGULARITY_TOLERANCE

  • PARALLELISM_TOLERANCE

  • PERPENDICULARITY_TOLERANCE

  • SYMMETRY_TOLERANCE

  • DATUM_TARGET

  • DATUM_FEATURE

It is possible to export PMI representation as polylines (text will be outlined) or tessellated (text will be filled).

Miscellaneous

The following file attributes can be exported: User Name, Organization Name, and Authorization Name.

User-defined attributes on geometry and part can be exported (AP242 only).

Validation properties on geometry, part and PMIs can be exported (AP242 only).

Limitations

Currently the HOOPS Exchange API does not support STEP drawings export.