And so it begins...

mods/artifact_world/mapgen.lua

@@ -0,0 +1,21 @@
+
+local vm_data = {}
+
+local c_stone = minetest.get_content_id("artifact:stone")
+
+minetest.register_on_generated(function(vm, minp, maxp)
+    local min, max = vm:get_emerged_area()
+    local va = VoxelArea(min, max)
+    
+    vm:get_data(vm_data)
+    
+    if max.y < 0 then
+        for i in va:iterp(minp, maxp) do
+            vm_data[i] = c_stone
+        end
+    end
+    
+    vm:set_data(vm_data)
+    minetest.generate_decorations(vm)
+    vm:calc_lighting()
+end)