Surface

Surface files store complete 3D geometry data and are imported from formats such as:

• STEP (.stp, .STP, .step, .STEP)

• IGES (.igs, .IGS, .iges, .IGES)

• OCC BRep (.brep, .BREP)

• Parasolid (.x_t, .X_T, .x_b, .X_B)

These formats use exact geometry definitions such as BRep and NURBS surfaces, preserve CAD features (holes, fillets, assemblies), and maintain topological relationships between parts. They are designed for interoperability, enabling precise model exchange between CAD, CAM, and CAE systems without loss of accuracy. Because they retain parametric structure and design intent, models in these formats remain editable and can be modified using Trim and Explode commands.

When exported from M-Star Pre for use in M-Star Solve, surface files are automatically tessellated into mesh form. Mesh quality plays a role in both visual fidelity and simulation performance. A coarse mesh can cause curved surfaces to appear faceted, potentially altering flow behavior near boundaries; while an overly fine mesh increases computational cost without improving physical accuracy. This point is discussed further as part of the Edit Mesh command.