diff --git a/lua/engine.lua b/lua/engine.lua
index 3d63f7b..1c3e6f1 100644
--- a/lua/engine.lua
+++ b/lua/engine.lua
@@ -369,17 +369,17 @@ local function get_flat_cave_node_types(minp, maxp)
     local bools = get_flat_cave_bools(minp, maxp)
 
     return Flat3dArray:from_func(minp, maxp, function (i, pos)
-        if not bools:get_pos(pos) then
-            return node_type.stone
+        if bools:get_pos(pos) then
+            return node_type.content
         -- Floor takes precedence
-        elseif pos.y == minp.y then -- Could be floor
+        elseif pos.y == maxp.y then -- Could be floor
             return node_type.unknown
-        elseif not bools:get_pos({ x = pos.x, y = pos.y - 1, z = pos.z }) then
+        elseif bools:get_pos({ x = pos.x, y = pos.y + 1, z = pos.z }) then
             return node_type.floor
         -- Then roof takes precedence
-        elseif pos.y == maxp.y then -- Could be roof
+        elseif pos.y == minp.y then -- Could be roof
             return node_type.unknown
-        elseif not bools:get_pos({ x = pos.x, y = pos.y + 1, z = pos.z }) then
+        elseif bools:get_pos({ x = pos.x, y = pos.y - 1, z = pos.z }) then
             return node_type.roof
         else
             -- Check for walls
@@ -393,29 +393,29 @@ local function get_flat_cave_node_types(minp, maxp)
 
             if left.x < minp.x then
                 on_edge = true
-            elseif not bools:get_pos(left) then
+            elseif bools:get_pos(left) then
                 return node_type.wall
             end
             if right.x > maxp.x then
                 on_edge = true
-            elseif not bools:get_pos(right) then
+            elseif bools:get_pos(right) then
                 return node_type.wall
             end
             if front.z < minp.z then
                 on_edge = true
-            elseif not bools:get_pos(front) then
+            elseif bools:get_pos(front) then
                 return node_type.wall
             end
             if back.z > maxp.z then
                 on_edge = true
-            elseif not bools:get_pos(back) then
+            elseif bools:get_pos(back) then
                 return node_type.wall
             end
 
             if on_edge then
                 return node_type.unknown
             else
-                return node_type.content
+                return node_type.stone
             end
         end
     end)