How to convert X_T
to Open CASCADE?

A file with extension X_T (Parasolid text files) is used by the Parasolid core created by Siemens PLM Software. It is being developed as a standard export format for distributing Parasolid CAD models.

The X_T file is a set of structured data containing information about the features of the model construction, the topology of its structural elements, color scheme, coordinates of drawing primitives, etc.

The X_T extension is unpretentious to adapt and can be exported / imported for use in a wide variety of CAD systems. It is stored in text format and can be exported and imported using a variety of other computer-aided design programs.

X_T files are used instead of the old version of the XMT_TXT and XMP_TXT files, which are less used than X_B (Parasolid binary files), and store the same data, but in binary format.

In solid modeling and computer-aided design, boundary representation—often abbreviated as B-rep or BREP—is a method for representing shapes using the limits. A solid is represented as a collection of connected surface elements, the boundary between solid and non-solid.

Boundary representation of models are composed of two parts: topology and geometry (surfaces, curves and points). The main topological items are: faces, edges and vertices. A face is a bounded portion of a surface; an edge is a bounded piece of a curve and a vertex lies at a point. Other elements are the shell (a set of connected faces), the loop (a circuit of edges bounding a face) and loop-edge links (also known as winged edge links or half-edges) which are used to create the edge circuits. The edges are like the edges of a table, bounding a surface portion.

Compared to the constructive solid geometry (CSG) representation, which uses only primitive objects and Boolean operations to combine them, boundary representation is more flexible and has a much richer operation set. In addition to the Boolean operations, B-rep has extrusion (or sweeping), chamfer, blending, drafting, shelling, tweaking and other operations which make use of these.