I'm working on a "lost civilization" fortress right now for fun, and I'm building everything on top of the magma sea. Nothing crazy, fort is stabilized. Time to drop some sand down here and cover up my tracks. On the map, there are a quite a few soil layers of clay loam and whatnot. But in one corner of the map there's a layer of red sand on top of white sand, on top of another layer of silty clay loam. I'm not splitting biomes on this map, but the sand is only there in the bottom right quadrant. I setup and dropped some tiles of both types of sand (variety!), BOOM. And what do I find? It has transformed into Silty Clay Loam- useless.
So now I spend a few hours on Google, and learned how to use TileTypes and changelayer, and it's no good. I do changelayer SAND_WHITE and I get 'Invalid material - you must select a type of stone or gem or soil.' Hmm. Same with all other SAND_X varieties. Tried it on the clay loam layer and the sand layers, no good. If you can use TileTypes to make anything more specific that "SOIL" I'd sure love to know. I know there's a bug related to soil types changing, seems like to the lowest layer of soil on the map. So I tried dropping 2 and 3 height drops- "paint m soil" several layers high, so I get a sandwich of clay loam, sand, sand. Drops down, and all 3 layers are loam.
Is there any way to get sand where I want it? Read about ways with mud, floor fungus, furrow and get a random type, but that's pretty hit or miss. I really don't understand the "Invalid material" thing with changelayer. I checked the wiki for the raws- the name seems proper. I tried INORGANIC:SAND_WHITE, get a "no known material" error. Can anybody enlighten me here? Thanks!