Change parameters for Hybrid mesh
 

I have a hybrid mesh (Tetra with hex core). I can adjust the max element size for tetra and hex. however, is there a way that I can define the number of layers or max height (thickness) of the tetra elements with the hexcore option enabled?

What I have seen is that the hex-core automatically determines the height of the tetra and hex layers. I tried changing the tetra ratio, height etc from the surface mesh, but nothing seems to work!

Also another question. Is there a way that I can increase the mesh density of the tet in one area (closer to one wall and reducing outwards until it hits the other wall) without the mesh density option in ICEM. I want a gradual decrement in mesh density for the unstruct tet mesh. (again using the height ratio didnt help!!

which software?

Sorry: ICEM
I have added couple of pics to show the coarse mesh:

http://img689.imageshack.us/gal.php?...ucthexwith.jpg
http://img689.imageshack.us/g/hybrid...cthexwith.jpg/http://img689.imageshack.us/i/hybrid...cthexwith.jpg/
http://img594.imageshack.us/i/bounda...eshstrctu.jpg/
http://img689.imageshack.us/g/hybrid...cthexwith.jpg/

Nope, sorry, the Hex Core doesn't provide that option to set the offset to the user...

Instead of Hex Core, I usually use the 12 tet to 1 hex conversion. This basically turns the octree tetras back into the original hexas...

As for wanting a smoother transition in tetra mesh size from one wall to the other, your best bet is to use the Delaunay method (perhaps with TGlib AF). The size transitions are built into OCTREE's algorithm, but you could start with Octree, then delete the volume mesh and smooth the surface mesh with laplace, then generate the delaunay fill and you will get your nice smooth transition.