Mesh 3D elements from a fixed 2D mesh

Suppose I have an element consisting of two cubes. One of the cube I want to mesh with hexahedron elements and the other cube with tetrahedron elements between the cubes . The face between the two cubes will have nodes that both builds up a structured mesh of quadrates  which I want to build the hexahedron mesh out of  and of split quadrates/triangles  that the tetrahedron mesh will be built by. So I first want to create the surface mesh (which is no problem) and I then want to create the two volume mesh with this surface mesh hold fix as a condition for the two mesh. Is their any way I can do this? I know how to create two different mesh at the same time with local hypotheses but I'm interested in how I can hold one surface fixed and create a mesh out of this. Thank you for any answers on this problem. /Jonas

Hello Jonas,
The easiest way to solve your problem is to create compound in geometry module and to use submesh technique. Follow scenario
in GEOM :
1. Build Compound combining 2 cubesIn MESH:
1. Create a Mesh (Geometry: " Compound ", Algorithms: "Wire discretisation", "Quadrangle (Mapping)", "Hexahedron(i,j,k)", Hypothesis “Nb.Segments" = 10, “Quadrangle Preferences”2. Create a SubMesh (Geometry: " Cube_1”, ", Algorithms: "Wire discretisation", “Triangle Mefisto”, "Netgen_3D”, Hypothesis “Nb.Segments" = 10, “Length from edges”, “Max. element Volume” = 1000
3. Compute mesh.
Grigory.
