can maps from other games be used

i know some engines have a completely different way of making maps, but i am aware that some are similar, is there any way they could be decompiled into hammer?

I personally don’t think so, unless you got some kind of converter.
I’m not very sure though.

Games before Hammer? Maybe…

Games after Hammer? Too advanced

I dont think it is really possible, you can always try to remake the maps from the game, but you cant convert them.

Hammer is brush-entity based, not geometry based.

This will make it ny impossible to find a converter.

Much easier to just re-create the map in hammer.

but doesnt the cod series use a simmilar thing (maybe even bsp)

No, it doesn’t use .bsp, .bsp files are brush based or so I believe, CoD maps are models I think.

IMO, brushes are easier to work with than with models.

CoD1 and 2 use .bsp but the version is not the same as Source engine.

Codradiant still uses brushes.

Could always decompile them to see what they look like?