Well, finally i find a way to do it. First:
•3 obj ; 2 walls and 1 roof
•all in rocks
btw if you have installed my old wall of rock here. delete it and install this one, because it already have the recolours of ice and new stones patterns.
ceiling roof cave works like a lamp, it will be placed at the roof alone. you don't have to use 9 or 0 for it. [yay]
i hope you all like this <3
use the cave walls and floors like i used in the pictures.
~~~~~update~~~~
Guys, i updated the roof. It was fading when we put many of them in the lot, but now is working fine.