https://explv.github.io/
Find the osrs maps here and get region ids you need.
Grab a data pack for osrs or dump yourself. What osrs data rev are you on? It can make a difference.
https://www.rune-server.ee/runescape...data-maps.html
Use the osrs map_index provided to get the object and landscape file ids for those region ids.
You can use the client or write your own program. To read it, here is pseudocode
Reader in
Length = read unsigned short
For length times {
regionid = read unsigned short
fileid1 = read unsigned short
fileid2 = read unsigned short
}
I dont know if it is land then obj or obj then land.
Use the index4 folder for the map .gz files using the file ids you found.
Pack the maps (dont overwrite existing maps unless it is the same, can just give it new number).
Update your map_index.