How do I place a block randomly on my plot but only on top of another block?

[luna_0_7]

I know how to place a block randomly, but I want these blocks to be placed on any elevation, but I can't figure out how to stop them from floating. Please help.

 

[Bromeo]

You could check if the block *one block* below it is not air using if block =

 

[Bromeo]

You could check if the block *one block* below it is not air using if block =

Or alternatively keep repeating downwards until you reach something that isn’t air, then shift one back up and place it there

 

[Mipoxa]

Or alternatively keep repeating downwards until you reach something that isn’t air, then shift one back up and place it there

In this case using a raycast would be more efficient, I think

 

[Bromeo]

I never thought about that