Bridges in prboom?

[CzechMate29200]

I was playing scythe 2 and I was wondering, how the hell do those bridges work in prboom??!? How are those made? It has something to do with a crusher. Thanks

[Ribbiks]

such bridges aren't prboom specific, the technique is vanilla compatible afaik: https://www.doomworld.com/tutorials/fx7.php

 

if you're looking to map for boom and above you can utilize "transfer height" specials (action 242): https://zdoom.org/wiki/Transfer_Heights

 

for zdoom and beyond you can do full 3d with fancy techniques that are above my pay grade.