How to convert CATIA V6 (3D XML)
to BREP?

3DXML is an open-standard proprietary 3D file format developed and supported by Dassault Systemes. 3DXML files are typically created as exports from Dassault Systemes' 3DEXPERIENCE application. The 3DXML file is a zip archive file consisting of a BOM file and one or more 3D representations stored in either XML or binary format. Compact file size allows users to transfer 3D XML quickly and embed it into websites, emails, and various MS Office documents. Therefore, the format is commonly used to integrate 3D data into technical documentation.

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.