Change the material of an entire geology layer.
Note that one layer can stretch across many z-levels, and changes to the geology layer will affect all surrounding regions, not just your embark! Mineral veins and gem clusters will not be affected. Use changevein if you want to modify those.
tl;dr: You will end up with changing large areas in one go, especially if you use it in lower z levels. Use this command with care!
changelayer <material RAW id> [<options>]
When run without options,
only affect the geology layer at the current cursor position
only affect the biome that covers the current cursor position
not allow changing stone to soil and vice versa
You can use the probe command on various tiles around your map to find valid material RAW ids and to get an idea how layers and biomes are distributed.
Convert the layer at the cursor position into granite.
changelayer SILTY_CLAY force
Convert the layer at the cursor position into clay, even if it’s stone.
changelayer MARBLE all_biomes all_layers
Convert all layers of all biomes which are not soil into marble.
If you use changelayer and nothing happens, try to pause/unpause the game for a while and move the cursor to another tile. Then try again. If that doesn’t help, then try to temporarily change some other layer, undo your changes, and try again for the layer you want to change. Saving and reloading your map also sometimes helps.
You should be fine if you only change single layers without the use of ‘force’. Still, it’s advisable to save your game before messing with the map.
When you force changelayer to convert soil to stone, you might see some weird stuff (flashing tiles, tiles changed all over place etc). Try reverting the changes manually or even better use an older savegame. You did save your game, right?
Change the corresponding geology layer for all biomes on your map. Be aware that the same geology layer can AND WILL be on different z-levels for different biomes.
Change all geology layers on your map (only for the selected biome unless
all_biomesis also specified). Candy mountain, anyone? Will make your map quite boring, but tidy.
Allow changing stone to soil and vice versa. THIS CAN HAVE WEIRD EFFECTS, USE WITH CARE AND SAVE FIRST. Note that soil will not be magically replaced with stone. You will, however, get a stone floor after digging, so it will allow the floor to be engraved. Similarly, stone will not be magically replaced with soil, but you will get a soil floor after digging, so it could be helpful for creating farm plots on maps with no soil.
Output details about what is being changed.