I want to check if the spot is free (SetPos) and if it’s not then use a different one. I looked it up and I can’t find anything to check if an entity is already in spot.
Uhh this isn’t exacly minecraft coordinate system. Two ents could be almost perfectly stuck inside each other and they would have different world origins. World coordinates in source are very precise so I’d guess your best bet is to use one of the FindIn* functions to check the surrounding area.
I recently added additional examples to the PlayerSelectSpawn tutorial: https://dl.dropboxusercontent.com/u/26074909/tutoring/_systems/playerselectspawn_system.lua.html
You run the exact same logic for props, or whatever… You could use recursion, or iteration…
Just do a hull trace upwards. Look up util.TraceHull