turf
wall
icon = 'block.dmi'
density = 1
floor
UpperGrass {name = "UpperGrass"; icon = 'grass.dmi'; icon_state = "1"; density = 1}
Lowergrass {name = "Lowergrass"; icon = 'grass.dmi'; icon_state = "2"; density = 1}
HELP!! this is how i do it but then my floors are grey on Object!
Not sure if that'll change anything at all but try it anyway.