FoamGeo is the module to model regular Kelvin structures and random foams in GeoDict. A foam consists of individual cells, which have the following components:

• A strut is the edge of a foam cell.
• A node is where the struts meet.
• A face is the surface surrounded by struts and nodes. When the structure is an open-cell foam (not a closed-cell foam), no faces are generated.

Two types of foams can be generated:

• Kelvin structures: a regular foam based on the bitruncated cubic honeycomb (or tessellation) by which space is partitioned into cells of equal volume. Kelvin structures are made up of 4 truncated octahedra around each vertex. Being composed entirely of truncated octahedra, it is cell-transitive. It is also edge-transitive, with 2 hexagons and one square on each edge, and vertex-transitive. It is one of 28 uniform honeycombs.

• Random Foams are based on the Voronoi tessellation (also called Voronoi decomposition, Voronoi partition or Dirichlet tessellation). It is a way of dividing space into a number of regions. A set of points (called seeds, sites, or generators) is specified beforehand and for each seed there will be a corresponding region consisting of all points closer to that seed than to any other. The regions are called Voronoi cells.