Swimming Pool Problem

[WolfBoy]

Hello all. I am making a swimming pool that goes down into ground. I`m trying to set the levels on it but I can`t seem to get it to digg down, in ingame. Any tip to give ?

Another thing is that I have tryed to imported into my map. I set it down and start sculpting inside the pool, but again, no matter what I do the ground keep coming out on the sides. I have also tryed to adjust the sliders but this sculping tool is a pain in the butt. Any tip to give ?

I have made this pool in the giants editor by using cubes and planes. I have also set collision on the walls. I set it to ff and collision on all trhe walls.
is there a collision that I can set to avoid the ground to mess up on the outside when I using this tool ?


Thank you.