Description

GEOM2GEO Generate GEO geometry data for use with Gmsh.

[ GEO ] = GEOM2GEO( SIN, HMAX, HMAXB, HMAXP, FILE_NAME, FID_LOG, TOL, F_COMPOUND, I_VER, IND_GOBJ, OPS, P_FIX, USE_CAD )

Converts a geom struct to GEO data for use with the mesh generator Gmsh.

SIN can either be a valid geometry or precomputed GEO struct, HMAX, and HMAXB are scalars or arrays indicating grid sizes for subdomains and boundaries. FILE_NAME is optional and enables output to file (writes a geo file, default featool_gmsh). FID_LOG specifies a message log file handle (negative for gui output or empty for no output). The optional input argument TOL defines the tolerance for deduplication and zeroing vertex coordinates (default eps*1e3).

HMAX, HMAXB, and HMAXP are used to calculate and prescribe the mesh sizes. HMAX is a scalar or array prescribing mesh sizes for subdomains, while HMAXB and HMAXP corresponds to boundary and vertex mesh sizes. Mesh sizes are prescribed in Gmsh Restrict Fields for edges and faces, respectively. A non-zero and non-empty HMAX assigns mesh size values to boundary fields connected to subdomains. If HMAX is an array with positive values the minimum value will be used, while negative HMAX values prescribes the mean absolute for each boundary. If HMAXB is given the corresponding boundary values are overwritten (HMAXB overrides HMAX).

The F_COMPOUND flag indicates if Gmsh compound lines and surfaces should be used (default true). The I_VER interger determines the Gmsh geo output syntax, vertion >= 4 (default) or older v3 syntax.

IND_GOBJ is an index vector to the geometry objects to output, or empty if the geometry should be analyzed and decomposed in to minimal regions (default).

The BIX output GEO struct field contains boundary numbers matching to physical followed by additional compound line entries in 2D and surfaces in 3D. BIX can thus be used to set geometrical boundary numbers during import.

P_FIX is an optional array of points to which should be in the resulting mesh (in addition to point objects).

USE_CAD (default true) is an optional logical switch which selects use (merge) of CAD format files (BREP, STEP, IGES) in Gmsh instead of converting to Gmsh object primitives.

See also: geo2geom