Installation

Generally we support two main ways of installing CAD_to_OpenMC: through pip and through conda/mamba. In the former case there is an additional dependency problem in terms of MOAB (short for Mesh Oriented datABase) which is not yet available in the PYPI package index.

In a virtual python environment using pip

replace <name> with an arbitrary name for your virtual environment

In the directory where you want your environment to reside do: python -m venv <name>
Activate the environment: source <name>/bin/activate
Build and install moab (if not already installed). The moab team relies on conda for standard installation but are working on a pip-based solution. Once that is done moab would simply be added to the requirements-file instead and installed automatically. For now we follow either of two procedures:
1. Install moab from source:
  1. Clone the moab code-repository: e.g. git clone git@bitbucket.org:fathomteam/moab.git
  2. Configure and build the code:
```
mkdir build;
cd build; cmake .. -DENABLE_PYMOAB=1 -DENABLE_HDF5=1 -DCMAKE_INSTALL_PREFIX=<name>;
make;
make install;
```
  1. Additionally you will need to build the python interface layer.
```
cd pymoab
sudo python setup.py install
```
2. Use 3rd party built python wheels: pip-install a specific wheel corresponding to the python version you use.
```
pip install https://github.com/shimwell/wheels/raw/refs/heads/main/moab/moab-wheels-ubuntu-latest/moab-5.5.1-cp{pyv}-cp{pyv}-manylinux_2_28_x86_64.whl
```
  where {pyv} refers to an abbreviated python version: “312” for python 3.12, etc.
Install the main package: pip install CAD_to_OpenMC. This will pip-install all the required python packages in the virtual environment. This ensures that no additional conflicts are introduced with the system python.

Should you wish to install the development version of this package you may do so by cloning this repository and replace the last command by: pip install <path/to/repo>. This procedure will build and install the python package locally directly from source.

Optionally install the msh refinement tool mmg (https://www.mmgtools.org), which may be run in conjunction with the cq/stl-mesher backend to avoid the high aspect ratio triangles that this backend tends to produce. Arch-linux users may install this from the AUR, otherwise get the source (and build from that) or binary builds from the mmg-site.

In a conda environment

replace <name> with an arbitrary name for your virtual environment

If instead you prefer to use a conda-environment, this is now as simple as:

create an environment, e.g. conda create -n <name>
activate it: conda activate <name>
install CAD_to_OpenMC: conda install -c conda-forge cad-to-openmc

You may of course replace conda with mamba/micromamba, should you prefer to do so. In many cases conda and mamba are already configured by default to use the conda-forge channel. If that is the case you may omit “-c conda-forge”