u/Easy-Squirrel3078

Hey yall! Can somebody explain to me on how to select both these rings AND the air in between, so I can fill it?

Because if I expand the selection, it also expands vertically, so it fills with blocks then not flat…

Ive tried what seems like everything and there’s just like no way :(

There’re 2 rings selected and the air in between is not selected, but I need to somehow include the air between…

P.S: they’re not selected on the pic, because I tried to shrink the selection by 200 blocks and MC crashed, so I captured it like this :/