Some models, when you place them, they modify the terrain to fill out
the model footprint whether wide or narrow, a smallfoot or a Bigfoot.
I think it's an .fpe setting -- perhaps our specialists can verify.
Looking for the thread that discussed snap / aligning objects 'b' button.
Where did it go... ? lol
I got the click-to-build-walls -- demonstration script done as I suggested in that thread...