Creating filters for Lua files in VS using CMake's source_group

I've been able to easily get all my headers and source files organized using filters like so:

source_group(Source\ Files\\network FILES 
network/lobbylist.cpp
network/network.cpp
network/networkenet.cpp
network/networkfactory.cpp
network/networklinux.cpp
network/networkraw.cpp
network/networkwin.cpp
)

However, today I started adding Lua scripts to my project and found that, although no errors were displayed during project generation and everything seemed to be spelled correctly, CMake didn't add a new filter for the scripts in the solution at all.

source_group(Source\ Files\\scripts F开发者_运维技巧ILES 
scripts/en_lang.lua
)

I also tried putting the group under the Header Files filter and under the project root, but no go. Does CMake simply not recognize or know what to do with non-.h/.hpp/.c/.cpp/etc files? Is there any way to get around this? Obviously I can still edit the scripts in a separate window or open it manually in VS, but having it right there in the solution explorer would be preferable.

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You have to add the lua files to ADD_EXECUTABLE