Calculate vertices of isoquant triangle(s) in a 3-D array of right regular hexahedra. This loops through a 3-D array and calls DrawHex to calculate the triangulation of each hexahedral cell.
int Draw3DBlock ( int xd, int yd, int zd, int xs, int ys, int zs, int xm, int ym, int zm, PetscScalar* minmax, PetscScalar* vals, int skip, int n_quants, PetscScalar* isoquants, PetscScalar* colors )