How to convert Parasolid
to Open CASCADE?

Parasolid

Parasolid file format is native for Parasolid geometrical kernel. Today it is widely used in a range of applications, including SolidWorks, SolidEdge, NX, Microstation, Ansys, Abaqus and others. Parasolid has two primary file extensions: .x_t, which is text based, and .x_b – binary-based format. Parasolid is also used to provide precise geometrical definitions of parts in JT files (as XT B-Rep data segments). CAD Exchanger can read files compliant with the entire range of Parasolid file format (schema) starting from v0.15 and up to version 32 (as of time of writing this page). Likewise, CAD Exchanger writes file compliant with all Parasolid schemas.

Open CASCADE

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.