AIR-HPC / AIR Toolkits / VOFTools

Cell-level computational geometry

VOFTools

Cell-level analytical and geometrical tools for volume-of-fluid methods in arbitrary polygonal and polyhedral cells.

Latest release v5.1Fortran + C interoperabilityGPL-3.0-or-later

Overview

VOFTools is a Fortran library providing analytical and geometrical operations for two- and three-dimensional volume-of-fluid methods on arbitrary convex and non-convex cells. It supplies foundational cell-level kernels used by hiVOF and gVOF while remaining an independently versioned and citable package.

Its ISO_C_BINDING-based interface, introduced in v5.1, supports use from C and C-compatible external frameworks while preserving the independent Fortran implementation.

Main capabilities

  • Area and volume computation for arbitrary polygonal and polyhedral cells.
  • Polygon–half-space and polyhedron–half-space intersection and geometric truncation.
  • Positioning of piecewise linear interface calculation (PLIC) interfaces through area/volume conservation enforcement.
  • Initialization of liquid area and volume fractions.
  • Shortest distance from a point to a reconstructed PLIC interface.
  • Intersection kernels supporting fluid-volume intersection advection and wetted-area time-integration advection schemes.

Software characteristics

Language
Fortran, free-form .f90
Interfaces
Fortran and C compatible
Build
Makefile; no external dependencies
Reference compiler
GNU Fortran
Platforms
Primarily Linux and macOS
Parallelization
Cell-level kernels; no internal parallelism

Earlier versions were also compiled successfully with Intel Fortran and NAG Fortran.

Documentation, releases and downloads

VOFTools v5.1 was published on 23 June 2026. Its Zenodo package contains the source code, Fortran and C tests, Makefile, user manual, documented examples with reference results, change log and license.

Download v5.1 from Zenodo

Concept DOI10.5281/zenodo.20539881

VOFTools v6 is in preparation, with planned f2py bindings and binary distributions through PyPI.

Citation and license

López, J. (2026). VOFTools 5.1: Enhanced analytical and geometrical tools for VOF methods in arbitrary grids (Version 5.1) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.20810740

Distributed under the GNU General Public License v3 or later (GPL-3.0-or-later).

Related publications

Selected papers document the library’s development from its original analytical and geometrical tools to volume conservation enforcement, initialization and non-convex geometries.

López, J. & Hernández, J. (2008). Analytical and geometrical tools for 3D volume of fluid methods in general grids. Journal of Computational Physics, 227, 5939–5948. DOI
López, J. et al. (2018). VOFTools — A software package of calculation tools for volume of fluid methods using general convex grids. Computer Physics Communications, 223, 45–54. DOI
López, J. et al. (2020). VOFTools 5: An extension to non-convex geometries. Computer Physics Communications, 252, 107277. DOI