Make your own free website on
This following page is an example of my STEP work [see]. Basically, I convert Constructive Solid Geometry to a Facetted Boundary Representation using Euler Boolean operations. See Mantyla , "An Introduction to Solid Modelling" and Mortenson's "Geometric Modeling", and several papers by Greyer and Braid, (see Braid, Hillyard, Stroud "Stepwise construction of polyhedra in geomeric modeling", Mathematical methods in computer graphics and design, p123-141 AP, London, 1980), and's ACIS documentation for more details. Here is the class hierarchy for my project.
Following the technalink link, you will get a dialog box asking to allow the installation of an ActiveX control from TechnaSales. You must select "Yes" to allow the installation of this executable on your hard disk. The ActiveX control is very much like MS Media Player. We are working on an C#/.NET version of this component, but that is a big undertaking. Mostly, the GUI will be in C#, but not the conversion engine.
select "series An" button
on the next scene, "Provnair Series" select "Draw Part"
click the icon of the floppy, 2nd row, third from last.
save as
(Make sure that you chose the first pull down selection STEP Faceted *.stp). It takes a while for the file to appear.
You should get a output file like this.
 Now you need to be able to read a step formatted file.
This means that you need to a CAD STEP viewer like SolidEdge, SolidWorks, Catia, AutoCAD.
If you don't have one of those, you can download a trial viewer from a couple of sites.  Go to and search for CAD viewers STEP
You can use what I used for testing, e.g. WiseView32 from
Download the AutoVue viewer from !
OpenCascade is a free CAD tool for non-commercial work. Example faceted representation step format
and Advanced BREP step format
or CSG step format
Here are my source and ccdoc files zipped up.
Back to technalink.