Tiles can still be put in through the texsrc folder but the size and names are differant. Every tile is made up of 4 subtypes combined in any 1 of 256 possable ways to create 1 tile. Each subtile is 512 X 512 and all must tile with each other. The numbers for farm would be terr0003, terr0103, terr0203 & terr0303. Transitions are done automatically. Now the downside, all objects on the tile will still be there so you'll have farmhouses & barns on your jungle tiles. Also they don't automatically show up in the game, every player has to delete the terrxxxx.TCA files from the cache\stdshape folder.