DESCRIPTION OF A NON-STRUCTURED MESH OF HEXAHEDRONS
This mesh is defined by a set of hexahedrons. Each hexahedron is defined by 8
vertex numbers given in an array.
The mesh must be "rebuilt" : hexahedron faces must be referenced exactly twice
in the mesh, this means a face must belong to two mesh elements. (this is a
topological and not geometric reference). Face which belong to only one mesh
element define the border of the mesh (or the skin of the mesh)
Hexahedrons must be numbered as follows:
Following rule is applied: for each hexahedron, the first 4 indices define a
mesh face, and direct this face to the exterior side of the hexahedron
Data structure for this mesh is defined by ns_hexahedrons, Tmesh3D,
Tscalar3D_data and Tvec3D_data :
- num_hexahedrons Number of hexahedrons of the mesh
- num_nodes Number of mesh nodes
- hexahedron_nodes hexahedron_nodes[i][j] is the jth vertex
of the ith hexahedron
- [forall]i 0<=i<num_hexahedrons, [forall]j 0<=j<8
- nodes array of mesh nodes
- s s[i] is scalar value for ith node
- v v[i] is vector value for ith node
Remark : The array nodes may include vertices which do not belong to
any hexahedron of the mesh. In this case the mesh does not provide a continuous
numeration of the vertices and num_nodes is not the total number of
vertices of the mesh but the dimension of nodes array.