Testing package and running examples

Testing with Model Benchmark Zoo

A minimal package that converts CAD geometry to DAGMC h5m files

cad-to-dagmc can create:

• surface meshes / faceted geometry / triangular meshes
• unstructured mesh / tetrahedral meshes / volume meshes

cad-to-dagmc can convert:

• STEP files
• CadQuery objects (in memory)

cad-to-dagmc aims to produce DAGMC compatible h5m files from CAD geometry is intended to convert STEP files or CadQuery objects to a DAGMC compatible h5m file.

The resulting DAGMC geometry can then be used for simulations in OpenMC or other supported codes.

This package is tested with pytest tests and also the DAGMC geometry made with this package is compared to simulation carried out with native constructive solid geometry, see Model Benchmark Zoo for more details.

Also checkout these other software projects that also create DAGMC geometry CAD-to-OpenMC, Stellarmesh and Coreform Cubit

Installation options

• Install using Mamba
• Install using Conda
• Install using Mamba and pip
• Install using Conda and pip
• Install using pip and source compilations

Install using Mamba

In principle, installing any Conda/Mamba distribution will work. A few Conda/Mamba options are:

• Miniforge (recommended as it includes mamba)
• Anaconda
• Miniconda

This example assumes you have installed the Miniforge option or separately have installed Mamba with conda install -c conda-forge mamba -y

Create a new environment, I've chosen Python 3.10 here but newer versions are also supported.

mamba create --name new_env python=3.10 -y

Activate the environment

mamba activate new_env

Then you can install the cad_to_dagmc package

mamba install -y -c conda-forge cad_to_dagmc

Install using Conda

In principle, installing any Conda/Mamba distribution will work. A few Conda/Mamba options are:

• Miniforge (recommended as it includes mamba)
• Anaconda
• Miniconda

Create a new environment, I've chosen Python 3.10 here but newer versions are also supported.

conda create --name new_env python=3.10 -y

Activate the environment

conda activate new_env

Then you can install the cad_to_dagmc package

conda install -y -c conda-forge cad_to_dagmc

Install using Mamba and pip

In principle, installing any Conda/Mamba distribution will work. A few Conda/Mamba options are:

• Miniforge (recommended as it includes mamba)
• Anaconda
• Miniconda

This example assumes you have installed the Miniforge option or separately have installed Mamba with conda install -c conda-forge mamba -y

Create a new environment, I've chosen Python 3.10 here but newer versions are also supported.

mamba create --name new_env python=3.10 -y

Activate the environment

mamba activate new_env

Install the dependencies

mamba install -y -c conda-forge "moab>=5.3.0" gmsh python-gmsh

Then you can install the cad_to_dagmc package

pip install cad_to_dagmc

Install using Conda and pip

In principle, installing any Conda/Mamba distribution will work. A few Conda/Mamba options are:

• Miniforge (recommended as it includes mamba)
• Anaconda
• Miniconda

This example uses Conda to install some dependencies that are not available via PyPi.

Create a new environment

conda create --name new_env python=3.10 -y

Activate the environment

conda activate new_env

Install the dependencies

conda install -y -c conda-forge "moab>=5.3.0" gmsh python-gmsh

Then you can install the cad_to_dagmc package

pip install cad_to_dagmc

Install using pip and source compilations

It should possible to avoid the use of conda and installing using pip and compiling from source.

First compile MOAB (and install Pymoab) from source

Then install gmsh from source (installing from pip appears to cause conflicts with the open cascade used in ocp and cadquery)

Then you can install the cad_to_dagmc package with pip

pip install cad_to_dagmc

Install with OpenMC or other particle transport codes

You may also want to install OpenMC with DAGMC to make use of the h5m geometry files produced in simulations. However you could also use other supported particle transport codes such as MCNP, FLUKA and others link to DAGMC documentation.

To install OpenMC you can run mamba install -c conda-forge openmc however this more specific command makes sure the latest version of OpenMC which contains DAGMC is chosen by conda / mamba

mamba install -c conda-forge -y "openmc=0.14.0=dagmc*nompi*"

It might not be possible to install OpenMC and cad-to-dagmc in the same conda/mamba python environment so you may have to create a new conda/mamba environment and install OpenMC there.

Another option would be to install OpenMC from source which would also need compiling with MOAB and DAGMC options.

Known incompatibilities

The package requires newer versions of Linux. For example the package does not work on Ubuntu 18.04 or older.

The package requires newer versions of pip. It is recommended to ensure that your version of pip is up to date. This can be done with python -m pip install --upgrade pip

Installing one of the package dependancies (gmsh) with pip appears to result in occational errors when passing cad objects between cadquery / ocp and gmsh. The conda install gmsh appears to work fine.

Usage - creation of DAGMC h5m files

For examples see the examples folder

Usage - simulation with transport code

For examples see the examples folder

For more examples see the CAD tasks in the neutronics-workshop and model benchmark zoo