Fix terrain_scale bug.

terrain.lua

@@ -295,7 +295,7 @@ loud_walking.terrain = function(minp, maxp, data, p2data, area, baseline, height
       index = (z - minp.z) * csize.x + (x - minp.x) + 1
       height = half_pod.y - 5
       if not (biome_name == "underground" or biome_name == 'control') then
-        height = get_height(fdx, fdz, index, biomes[biome_name].terrain_scale, ocean) or height
+        height = get_height(fdx, fdz, index, biomes[biome_name].terrain_scale or 1, ocean) or height
         if ocean then
           height = height - 10
         end