STEP Reader

The STEP Reader provides full access to the assembly, B-rep, view and PMI data stored within a STEP file. The specific APs supported for STEP are AP 203 E1/E2 and AP214. Support for AP 242 is included however official support will not be announced until the specification is ratified. A file does not need to have a particular extension to be read correctly by HOOPS Exchange, however, the file extensions of STEP files you can expect are:

  • .STEP

  • .STP

  • .STP.Z

Our readers are updated to the latest released version within 90 days of the release of the authoring software. You can see the exact version supported in the current release here.

Assembly

In addition to full support of the assembly tree our STEP reader will also honor external file references including those that point to other non-STEP files.

B-rep

We provide full support for the B-rep model defined in a STEP file. Evaluators are provided to allow you to directly query these geometries.

The specific surfaces supported by STEP are:

  • B_SPLINE_SURFACE

  • B_SPLINE_SURFACE_WITH_KNOTS

  • BEZIER_SURFACE

  • BOUNDED_SURFACE

  • CONICAL_SURFACE

  • CURVE_BOUNDED_SURFACE

  • CYLINDRICAL_SURFACE

  • OFFSET_SURFACE

  • QUASI_UNIFORM_SURFACE

  • RATIONAL_B_SPLINE_SURFACE

  • RECTANGULAR_TRIMMED_SURFACE

  • SPHERICAL_SURFACE

  • SURFACE_OF_LINEAR_EXTRUSION

  • SURFACE_OF_REVOLUTION

  • TOROIDAL_SURFACE

  • UNIFORM_SURFACE

  • DEGENERATE_TOROIDAL_SURFACE

The specific curves supported by STEP are:

  • QUASI_UNIFORM_CURVE

  • UNIFORM_CURVE

  • BEZIER_CURVE

  • B_SPLINE_CURVE

  • B_SPLINE_CURVE_WITH_KNOTS

  • CIRCLE

  • ELLIPSE

  • PARABOLA

  • HYPERBOLA

  • COMPOSITE_CURVE

  • POLYLINE

  • RATIONAL_B_SPLINE_CURVE

  • INTERSECTION_CURVE

  • SURFACE_CURVE

Visualization

This visualization data for this format is generated by the HOOPS Exchange tessellation engine.

Views

HOOPS Exchange provides support for the SAVED VIEWS concept in STEP. We specifically support the following SAVED VIEW concepts:

  • DRAUGTHING_MODEL

  • CAMERA_MODEL_D3

  • CAMERA_MODEL_D3_MULTI_CLIPPING

PMI

We provide support for the graphical representation of PMI which includes a link back to the referenced entity. The specific PMI supported includes:

  • Datum

  • Datum Target

  • Dimension (angular)

  • Dimension (curve)

  • Dimension (diameter)

  • Dimension (general)

  • Dimension (linear)

  • Dimension (ordinate)

  • Dimension (radial)

  • Feature control frame

  • Label

  • Note

  • Roughness

  • Weld

Miscellaneous

Our STEP reader provides support for both user defined and validation properties defined at a part level. Also, support for compressed STEP files is included.

Our STEP reader includes a built-in healing algorithm. However, in the interest of performance, it is not enabled by default.

For shell based surface models, each body is put into a separate B-rep entity. This can be toggled using the m_bSplitSHELL_BASED_SURFACE_MODEL flag.

Import Options Specific to STEP

None

Limitations

Support for STEP AP 242 is included however it will not be officially supported until the specification is ratified.