g-step — STEP Translator/Exporter (BRL-CAD to STEP AP203)


g-step -o output_file.stp database.g [object(s)]


g-step converts the specified objects of the BRL-CAD database, database.g, to a STEP AP203 file, output_file.stp.

The following options are recognized.

-o output_file_or_directory

Specifies the output file to which the STEP output is written.

There are some inherent limits when writing BRL-CAD geometry to the AP203 format. The primary solid object representation used by STEP is the NURBS Boundary Representation, and BRL-CAD's CSG models must be converted to that representation upon export. Boolean operations are not supported in AP203, so the objects are either to write out all objects and post-process them in another system to get the final forms or have BRL-CAD itself perform the boolean evaluation at the region level. The latter will eventually be the default, but for the moment that feature is not yet ready for general deployment.


Example 1. Export All .g File Contents

g-step -o m35.stp m35.g

Writes out the full hierarchy of the .g file to m35.stp .

Example 2. Export Parts of a .g File

g-step -o m35.stp m35.g cab suspension

Writes out the hierarchies associated with the combs cab and suspension, along with all combs and solids needed to define those hierarchies.




This software is Copyright (c) 1993-2016 by the United States Government as represented by U.S. Army Research Laboratory.


Reports of bugs or problems should be submitted via electronic mail to <>.