Convert mesh files between formats supported by MOAB, optionally extracting subsets of the input.

Synopsis

mbconvert [-h|-l]
 
mbconvert [-f format] [-a sat_file|-A] [-t] [-g]
          [-o option] [-O option] [-I dim] [-p|-P]
          [-v vol_ids] [-s surf_ids] [-c curve_ids] [-V vert_ids]
          [-m block_ids] [-d nodeset_ids] [-n sideset_ids] [-D part_ids]
          [-1] [-2] [-3]
          input_file [input_file2 ...] output_file

Description

mbconvert uses the MOAB library to translate between mesh file formats or to extract subsets of a mesh file. The output file type is determined from the file extension when -f is not given. Use -l to list supported file formats.

id_list arguments accept individual IDs or ranges separated by commas (e.g. 1,5,10-15,20). Lists may not contain spaces.

Any combination of subset options can be specified (repeating a flag with a different id-list is allowed); the output contains the union. With no subset options the entire input mesh is written.

Writer- and reader-specific option strings for the -o and -O flags are documented in ../README.IO.

Options

General

Flag	Description
`-h`	Print help to stdout and exit.
`-l`	List supported file formats and exit.
`-f <format>`	Specify the output file format explicitly.
`-t`	Print read/write timing data.
`-g`	Enable verbose / debug output.
`-I <dim>`	Generate internal / adjacent entities of dimension `<dim>` (1 or 2).
`--`	Treat all subsequent arguments as file names (lets file names begin with `-`).

Format-specific

Flag	Description
`-a <sat_file>`	ACIS SAT file dumped by the `.cub` reader. Equivalent to `-O SAT_FILE=<sat_file>`.
`-A`	Tell the `.cub` reader to not dump a SAT file (deprecated; current default).

I/O options

Flag	Description
`-o <option>`	Pass a writer option. Repeat for multiple options.
`-O <option>`	Pass a reader option. Repeat for multiple options.

Note: lowercase -o is for writes; uppercase -O is for reads. (The older mbconvert.man page had these descriptions swapped; this doc and the in-binary help have it right.)

The most commonly used writer options:

WRITE_FORMAT={SCRIP|ESMF|DOMAIN} — Force NetCDF output into a specific grid layout, regardless of the source mesh's __MESH_TYPE tag. See Cross-format NetCDF conversion below.
PARALLEL=WRITE_PART — Set automatically by -M; rarely needed by hand.

Parallel (requires MPI build)

Flag	Description
`-P`	Append `.<rank>` to the output file name (per-rank files).
`-p`	Replace every `%` in input and output file names with the world-comm rank.
`-M[0\\|1\\|2]`	Read/write in parallel; optional value selects `resolve_shared_ents` (1) or `exchange_ghosts` (2) on top.
`-z <file>`	Read Metis partition info for an MPAS grid file and emit an `.h5m` partition.

TempestRemap integration (when MOAB is built with TempestRemap)

Flag	Description
`-B`	Use the TempestRemap Exodus reader, then convert to MOAB.
`-b`	Convert a MOAB mesh and write via the TempestRemap Exodus writer.
`-S`	Scale a climate mesh to the unit sphere.
`-i <tag>`	Name of the global-DoF tag to use with `mbtempest`.
`-r <order>`	Order of the field DoF (FV=1, SE=[1..N]).

Subset selection by geometric topology / sets

Each of the following flags is followed by an ID list (commas, hyphens for ranges; no spaces):

Flag	Selects
`-v`	Geometric volumes
`-s`	Geometric surfaces
`-c`	Geometric curves
`-V`	Geometric vertices
`-m`	Material sets (blocks)
`-d`	Dirichlet sets (nodesets)
`-n`	Neumann sets (sidesets)
`-D`	Parallel partitioning sets (`PARALLEL_PARTITION`)

Subset selection by element dimension

Flag	Description
`-1`	Edges
`-2`	Triangles, quads, polygons
`-3`	Tets, hexes, prisms, etc. (Vertices are always exported.)

Examples

Format conversion (extension-driven)

mbconvert mesh.exo  mesh.h5m       # Exodus → MOAB HDF5
mbconvert mesh.h5m  mesh.vtk       # MOAB HDF5 → VTK
mbconvert mesh.nc   mesh.h5m       # NetCDF (MPAS/HOMME/Euler/...) → MOAB HDF5

Cross-format NetCDF conversion

The new WRITE_FORMAT option lets you re-emit the mesh in a different NetCDF grid layout. Source can be any reader-supported format — NetCDF (MPAS/HOMME/CAM/SCRIP/ESMF/Domain), HDF5 (.h5m), Exodus (.exo), VTK, etc.

mbconvert -o WRITE_FORMAT=SCRIP   in_mpas.nc  out_scrip.nc
mbconvert -o WRITE_FORMAT=ESMF    in_mpas.nc  out_esmf.nc
mbconvert -o WRITE_FORMAT=DOMAIN  in_mpas.nc  out_domain.nc

WRITE_FORMAT overrides the source mesh's stored __MESH_TYPE tag, so the same input can be emitted in any of the three grid layouts above.

Extracting subsets

# Just the material sets numbered 1, 3, 5
mbconvert -m 1,3,5  full.h5m  subset.h5m
 
# Surfaces 10 through 20
mbconvert -s 10-20  geom.h5m  surfaces.h5m
 
# Only the 3-D elements
mbconvert -3  mixed.h5m  volumes.h5m

Parallel

mpiexec -n 4 mbconvert -M2 -O PARALLEL=READ_PART big.h5m big_out.h5m

Convert + auto-generate adjacent entities

mbconvert -I 2 tets.exo tets_with_faces.h5m # add face adjacencies (dim 2)

Exit codes

Code	Meaning
0	Success
1	Usage error (bad flag or missing argument)
2	Read error (file open / parse failed)
3	Write error (writer rejected the file or set)
4	Other error (e.g. internal MOAB failure)
5	Entity / set not found for a subset filter