STEP or Standardized Exchange of Product is a CAD/CAM standard used to write out information for interchange by many modeler program like CATIA, PTC's Pro/Engineer, SolidEdge, and SolidWorks.
- 2D used in draft represent a vector layout
- 3D Boundary representations (BREP), have 4 major types:
- * I) Wireframe
- * II) Simple
- * III) Facetted representation,
- * IV) Advanced boundary representation .
[http://wheger.tripod.com/step/csg.stp CSG Constructive Solid Geometry]
In addition to representing geometry and topology, the format allows for representing additional engineering processes (e.g. stage of the model and annotations). Furthermore, one can write a feature history and associate to the CSG representation, the BREP.