Define the groups on the model of blocks
A group is characterized by the three following components:
- its type
- its name
- its elements
The six following classes define all the kind of group:
- group3d for groups of hexahedra,
- group2d for groups of facets,
- group1d for groups of segments,
- group0dVertices for groups of nodes on the edges,
- group0dFaces for groups of of nodes on the faces,
- group0dBlocks for groups of nodes in the blocks,
See TUI scripts and GUI part.