Et, oui il y a des iles flottantes dans terragen 2 ;D
J'ai lutté mais j'y suis arrivé. ;D
There is flying islands in Terragen 2 ;)
It took me hours but I succeeded !
If you're trying for Avatar type floating islands, I would make the planes a bit smaller. Maybe have them floating in a valley.
This is quite difficult to do. The image maps for the top and bottom displacements need to match. This would fix the hole on the left side of the floating island.
All in all this is a great leap for you skill. You have come a long way.
The concept is rather interesting and difficult to do. I think you should make the floating island a bit smaller and try to fix the hole. I agree with njeneb about the rest! Nice work!