Command line tool to convert MCNP mesh tallies to Visual ToolKit (VTK) formats.
Usage: mesh2vtk <file> <id> [options]
Arguments:
<file> Path to input meshtal file
<number> Mesh tally identifier
Options:
-v, --verbose... Verbose logging (-v, -vv)
-q, --quiet Supress all log output (overrules --verbose)
-h, --help Print help (see more with '--help')
Mesh options:
-t, --total Only extract 'Total' energy/time groups
-s, --scale <num> Multiply all results by a constant
--energy <list>... Filter energy group(s)
--time <list>... Filter time group(s)
-a, --absolute Filter by MeV/shakes rather than index
--no-error Exclude error mesh from output files
Vtk options:
-o, --output <name> Name of output file (excl. extension)
-f, --format <fmt> VTK output format
--resolution <res> Cylindrical mesh resolution
--endian <end> Byte ordering (endian)
--compressor <cmp> Comression method for xml
Note: --help shows more information and examples
Help is printed with the -h flag, and --help will show default values,
examples, and any important behaviour.
Direct from github:
cargo install --git https://github.com/repositony/mesh2vtk.gitAll executables are under ~/.cargo/bin/, which should already be in your path
after installing Rust.
Click here if you have never used Rust
If you have never used the Rust programming language, the toolchain is easily installed from the official website
Run the following to download and run rustup-init.sh, which will install
the Rust toolchain for your platform.
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | shThis should have added source $HOME/.cargo/env to the bash profile, so update
your environment with source ~/.bashrc.
On Windows, download and run rustup-init.exe from the official installs.
For more detail, see the OUT keyword for the FMESH card definition in
the MCNPv6.2
or MCNPv6.3
user manuals.
| Output format | Supported? | Description |
|---|---|---|
| COL | Yes | Column data (MCNP default) |
| CF | Yes | Column data including voxel volume |
| IJ | Yes | 2D matrix of I (col) and J (row) data, grouped by K |
| IK | Yes | 2D matrix of I (col) and K (row) data, grouped by J |
| JK | Yes | 2D matrix of J (col) and K (row) data, grouped by I |
| CUV (UKAEA) | Yes | UKAEA Cell-under-Voxel column data |
| NONE | N/A | NONE or unknown output format |
Once I get my paws on MCNPv6.3 this will be extended to include the new COLSCI, CFSCI, and XDMF/HDF5 formats.
All functionality is fully supported for both rectangular and cylindrical meshes.
| Mesh geometry | Supported? | MCNP designators |
|---|---|---|
| Rectangular | Yes | rec, xyz |
| Cylindrical | Yes | cyl, rzt |
| Spherical | No | sph, rpt |
Currently spherical meshes are not supported because barely anyone knows about them, let alone uses them. They are therefore a low priority, but raise an issue if anyone needs it.
Often only the Total energy/time bins are of interest, and a quick way of
only converting this subset is provided.
# Extract only the 'Total' energy and time groups
mesh2vtk /path/to/meshtal.msht 104 --totalExclude the uncertainty meshes from the VTK output. This may be desirable for extremely large meshtal files.
# Extract every energy and time group, with corresponding error meshes
mesh2vtk /path/to/meshtal.msht 104 --no-errorIf specific energy or time groups are required they can be filtered by group index.
# Extract specific energy and time groups by index
mesh2vtk /path/to/meshtal.msht 104 \
--energy 0 2 6 \
--time 1 totalThe keyword total can be used for the 'Total' energy/time groups for
convenience.
Filtering by index avoids the precision issues that accompany the extremely
limited MCNPv6.2 output formatting. However, if you really want to use absolute
values in units of MeV and shakes then include the --absolute flag.
# Extract specific energy and time groups by MeV/shakes values
mesh2vtk /path/to/meshtal.msht 104 \
--energy 1.0 20.0 1e2 \
--time 1e12 total \
--absoluteFor intuitive use, the groups correspond with values defined on the EMESH
and TMESH cards.
Note: mesh tallies label groups by the upper bounds defined on EMESH/TMESH
cards. i.e the energy group 1.0 corresponds to the 0.0>=E<1.0 bin,
though in reality 1 MeV particle would end up in the next group up.
MCNP normalises everything so it is often the case that the results must be rescaled to provide physical values.
# Rescale the result by a constant multiplier, e.g 6.50E+18 neutrons/s
mesh2vtk /path/to/meshtal.msht 104 --scale 6.50E+18Mesh rotations are a work in progress.
By default the file prefix is fmesh, so the output files will be
fmesh_<number>.vtk. This may be changed as needed.
# Change the output name to `myvtk_104.vtr`
mesh2vtk /path/to/meshtal.msht 104 --output myvtkMost useful may be the ability to decide on output formats. XML and legacy formats are supported, with both ascii and binary variants.
# Output as a binary vtk with legacy formatting
mesh2vtk /path/to/meshtal.msht 104 --format legacy-binaryFor more advanced usage, things like byte ordering and xml compression methods are also configurable.
# Output as an xml using lzma and setting the byte order to big endian
mesh2vtk /path/to/meshtal.msht 104 \
--format xml \
--compresser lzma \
--endian big-endianNote - VisIt only reads big-endian, but most sytems are natively little-endian. For personal convenience the default is big, but I am open to arguments for little endian as the default.
There is no VTK representation of cylindrical meshes, so an unstructured mesh is generated from verticies based on the RZT bounds.
Unfortunately, this can result in "low-resolution" plots for meshes with few theta bins. The number of theta bins can be increased to round off these edges. This simply subdivides the voxels by an integer number of theta bins.
# Subdivide voxels into 3 to round off cylindrical unstructured mesh
mesh2vtk /path/to/meshtal.msht 104 --resolution 3Note that this will increase the file size and memory usage significantly in some cases.