This is intended as a first 3D example, that can serve as a template for 3D problems. The equations are the same as in 'little_example', i.e. one Laplaces eq for u(x,y,z) and one diffusion equation for v(x,y,z). The geometry is a cube with a small half sphere inside. The boundary conditions for v are zero gradients on the four vertical faces of the cube, zero value at the bottom and top, and value one at the surface of the internal half sphere.

A 3D tetrahedral mesh is read from volume.msh. This grid file is produced by the commercial mesh generation program TGrid.

Boundary conditions are specified in bcdef.mshdat, with one set of conditions per face id, as specified in volume.msh. bcdef.mshdat is supplied by the user and can be edited as desired. In this case there are six entries, for the faces of the cube, and a seventh for the surface of the internal half sphere.

The file box_visu.v specifies a network for AVS/Express, which can be used to view the ouput in the out*.inp files.