STEP format
 
 
 

Standard for the Exchange of Product Data (STEP) is a ISO standard industrial automation systems product data representation and exchange format.

The file structure for a STEP file has a modular structure which makes it easier for developers to adapt the format to their own needs. The modules are called “classes” and are classified using numbers as follows:

STEP Application protocols

Each AP has its own subset of entities specific for the industry branch the AP was developed for Alias (supports the AP203 and the AP214.)

Application protocol support for STEP formats

The geometric descriptions contained within ISO10303-203 and ISO10303-214 are identical and comprises the core of the implementation of the translator. The following table shows the mappings made by Alias.

STEP Entity Alias Entity
Cartesian Point Point
Line B-spline Curve
Circle B-spline Curve
Ellipse B-spline Curve
Parabola B-spline Curve
Hyperbola B-spline Curve
PolyLine B-spline Curve
Composite Curve B-spline Curve (Grouped)
Trimmed Curve B-spline Curve
B-spline Curve B-spline Curve
Plane B-spline Surface
Cylindrical Surface B-spline Surface
Conical Surface B-spline Surface
Spherical Surface B-spline Surface
Toroidal Surface B-spline Surface
Surface of Linear Extrusion B-spline Surface
Surface of Revolution B-spline Surface
B-spline Surface B-spline Surface
Rectangular Trimmed Surface Trimmed Surface
Curve Bounded Surface Trimmed Surface
Offset Surface B-spline Surface
Manifold Solid Brep Shell (Closed)
Shell Based Surface Model Shell (Open/Closed)

Pro/ENGINEER options for export and import

To make the import and export of IGES and STEP files easier for Alias to read.

  1. In Pro/ENGINEER, select Utilities > Options
  2. Add the following data to the configuration file.
IGES_OUT_ALL_SRFS_AS 128
IGES_OUT_SPL_CRVS_AS_126 YES
IGES_OUT_SPL_SRFS_AS_128 YES
IGES_OUT_MIL_D_28000 NO
IGES_OUT_TRM_SRFS_AS_143 NO
IGES_OUT_TRIM_CURVE_DEVIATION DEFAULT
INTF_OUT_BLANKED_ENTITIES NO
INTF3D_OUT_EXTEND_SURFACE YES
INTF3D_OUT_FORCE_SURF_NORMALS YES
IGES_IN_106_F2_AS_SPLINE NO
IGES_IN_DWG_LINE_FONT YES
IGES_IN_DWG_PNT_ENT YES
IGES_IN_DWG_COLOR YES 
FIX_BOUNDARIES_ON_IMPORT YES