This software implements the distributed combinatorial maps [1], a distributed data-structure allowing to build, store and modify a topological representation of a 3D mesh. It is based on combinatorial maps [2] which allows to describe the topology of meshes subdivided in cells (vertices, edges, faces and volumes), and the additional geometrical layer called Linear cell complex [3].
To illustrate the interests of distributed combinatorial maps, this software implements a method to generate an hierarchical hexahedral mesh that approximate a given surface. This method takes a maximal subdivision level as parameter, and recursively subdivided all hexahedron that intersects the surface until having reached this maximal level.
3 versions of the software exist:

• sequential, one computer;
• parallel, multi-thread, one computer;
• parallel, mpi, several computers.

Several options are possible:

• enforce at most one level of subdivision of difference for two adjacent hexahedra;
• use transition patterns, to remove all the T-junctions. With this option, generate a mixed mesh, with hexahedra, tetrahedra, prisms and pyramids;
• project points on the surface, and remove degenerated elements;
• use cell transfer during the subdivision (method described in [4]) to accelerate the computation time of parallel versions.

[1] Distributed Combinatorial Maps for Parallel Mesh Processing; Damiand G., Gonzalez-Lorenzo A., Zara F., Dupont F.; Algorithms, Volume 11, Number 7, August 2018; https://doi.org/10.3390/a11070105
[2] Combinatorial Maps; Damiand G.; in CGAL User and Reference Manual, September 2011; https://www.cgal.org/Pkg/CombinatorialMaps
[3] Linear Cell Complexes; Damiand G.; in CGAL User and Reference Manual, March 2012; https://www.cgal.org/Pkg/LinearCellComplex
[4] Generic volume transfer for distributed mesh dynamic repartitioning; Damiand G., Jaillet F., Vidal V.; Engineering with Computers (EwC), June 2024; https://doi.org/10.1007/s00366-024-02008-9