Could someone make an overlay of the walls?

Creator's Corner Art Resources
#1

Could someone make this an overlay like only the walls and floors so in the scene i can make it rain inside and not inside?
if that makes sense. :confused:

730491561497d2dd2577be96d0f17abb
730491561497d2dd2577be96d0f17abb.jpg1250×1875 135 KB

#2

What do you mean?

#3

never mind it won’t work haha.

#4