- Have the features defined inside your map (I believe this generally requires something to be added in the features, objects3d and unittextures folders) - to test I suggest copying some from another map
- Open the map in springboard, your features should be present in the features menu
- When done placing features, export with file type "s11n object format"
- The exported file is itself a lua file, copy it into \mapconfig\ in your map .sdd
- Make sure your map has the right gadgets to read this file (I know s11n_gadget_load.lua and s11n_load_map_features.lua may need to go in the ./LuaRules/Gadgets folder but I am unsure whether this is necessary or sufficient)
- Check the s11n_load_map_features.lua gadget; near the top it should have a line looking like
local modelPath = "mapconfig/feature_list.lua"
Make sure this is pointing at the lua file you got from Springboard.
and hopefully your map should now have features.
(Somebody correct me if any of the above is incorrect.)