QUGaR is a C++ library designed to generate efficient quadrature rules for computing integrals in high-order unfitted/immersed/CutFEM methods. Additionally, it offers functionalities for generating unfitted domain reparameterizations for visualization purposes.

Currently, QUGaR is in its early stages. Initially, it supports unfitted domains created by implicit functions via Algoim. Future updates will include support for 2D and 3D B-reps.

While it is intended to be used with any library, QUGaR provides out-of-the-box interoperability with the FEniCSx Python interfaces. See the provided demos.

Here is a demo of QUGaR being used to reparametrize an unfitted hyperelastic body undergoing large deformations.

Documentation can be viewed at https://pantolin.github.io/qugar/main/index.html.

The easiest way to install QUGaR is to use the provided conda installation script. This script automatically sets up a conda environment with all required dependencies and builds both the C++ library and Python interface.

Prerequisite: Conda (Miniconda or Anaconda) must be installed on your system.

First clone the repository and go inside:

git clone https://github.com/pantolin/qugar.git
cd qugar

Then run the installation script:

bash setup_with_conda.sh

The script can be customized using environment variables:

• QUGAR_ENV_NAME - Name of the conda environment to create/use (default: qugar-env)
• PYTHON_VERSION - Python version to install (default: 3.10)
• INSTALL_LAPACKE - Install LAPACKE support (default: true)
• INSTALL_DOLFINX - Install DOLFINx for FEniCSx interoperability (default: true)
• USE_CONDA_COMPILERS - Use conda compilers instead of system compilers (default: false, Linux/Windows only; macOS always uses system compilers)
• SKIP_ENV_SETUP - Skip conda environment setup and use existing environment (default: false)

Example with custom options:

QUGAR_ENV_NAME=my-qugar-env PYTHON_VERSION=3.11 INSTALL_DOLFINX=false bash setup_with_conda.sh

If you prefer to install manually, follow the instructions below.

First clone the repository and go inside:

git clone https://github.com/pantolin/qugar.git
cd qugar

To build and install the C++ library, from the qugar/ root directory run:

cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -B build -S cpp/
cmake --build build --parallel 4
cmake --install build

QUGaR's Python interface requires the C++ library. So before installing the Python interface, make sure you have the C++ library installed.

To build and install the Python interface, under the qugar/ root directory run

python3 -m pip -v install -r ./python/build-requirements.txt
python3 -m pip -v install --no-build-isolation ./python -U

If you want to use QUGaR's functionalities together with FEniCSx library, install also DOLFINx (v0.9.0), including pyvista dependency.

Further details about the installation of the C++ and Python modules can be found at https://pantolin.github.io/qugar/main/installation.html.

It is also possible to use QUGaR from a docker container. The docker file may be built and run from the qugar/ root directory as

docker build -f docker/Dockerfile -t qugar .
docker run -it -v $(pwd):/root/shared -w /root/shared qugar bash -i

QUGaR is free software: you can redistribute it and/or modify it under the terms of the MIT license.