DESCRIPTION OF A HETEROGENEOUS NON-STRUCTURED MESH

This mesh is defined by a set of 4,5,6 or 8 vertices polygons. Each element is defined by 4,5,6 or 8 vertex numbers given in an array.

The mesh must be "rebuilt" : polygon 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). Polygon face which belong to only one mesh element define the border of the mesh (or the skin of the mesh)

Elements must be numbered as follows:

Following rule is applied: for each element, the first 3 or 4 indices (depending on element type) define an element face, and direct this face to the exterior side of the element

Data structure for this mesh is defined by ns_non_homo_3D, Tmesh3D, Tscalar3D_data and Tvec3D_data :

• num_elems Number of elements of the mesh
• num_nodes Number of mesh nodes
• elem_nodes elem_nodes[i].num_ints is the number of vertices of the ith element. (4, 5, 6 or 8)
• elem_nodes[i].ints[j] is the jth vertex of the ith element
• [forall]i 0<=i<num_elems, [forall]j 0<=j<elem_nodes[i].num_ints
• 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 element 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.