How to convert files from Unigraphics
to BREP?

Unigraphics is a former name for Siemens NX, an advanced CAD/CAM/CAE software application suite. However, veterans are still using the Unigraphics name.

In 2002, the new version of Siemens Unigraphics, merged with I-DEAS software, was released and called NX, which means "Next Generation". In fact, it was the last version of the software released under the Unigraphics name. All further releases became known as NX. So the addition of I-DEAS functionality to the core code of the Unigraphics has become the basis of the existing NX product line.

Siemens NX / Unigraphics use a .prt extension, which contains 3D CAD parts.

A Brep file is a 3D model stored in the boundary representation (also known as B-rep). The Brep format is a part of Open CASCADE Technology (OCCT).

The Brep structure is made up of two major components:

• topological components such as faces, vertices, and edges;
• links between components such as surfaces, points, and curves.

It comprises three-dimensional data such as vertices, edges, wires, faces, shells, solids, compounds, edge and face triangulations, polylines on triangulations, space location, and orientation.