added code

depends.txt

@@ -0,0 +1 @@
+default

init.lua

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+dofile(minetest.get_modpath("io_moon") .. "/sky.lua")
+dofile(minetest.get_modpath("io_moon") .. "/nodes.lua")
+dofile(minetest.get_modpath("io_moon") .. "/mapgen.lua")

mapgen.lua

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+--minetest.clear_registered_ores()
+minetest.clear_registered_biomes()
+minetest.clear_registered_decorations()
+
+--normal io biome
+	minetest.register_biome({
+		name = "io_moon",
+		--node_dust = "default:gravel",
+		node_top = "io_moon:ground_rocks",
+		depth_top = 1,
+		node_filler = "io_moon:stone",
+		depth_filler = 3,
+		node_stone = "io_moon:stone",
+		node_water_top = "default:lava_source",
+		depth_water_top = 1 ,
+		node_water = "default:lava_source",
+		node_river_water = "default:lava_source",
+		y_min = -31000,
+		y_max = 200,
+		heat_point = 100,
+		humidity_point = 0,
+	})
+
+--lava ore
+	minetest.register_ore({
+		ore_type       = "scatter",
+		ore            = "default:lava_source",
+		wherein        = "io_moon:stone",
+		clust_scarcity = 9 * 9 * 9,
+		clust_num_ores = 12,
+		clust_size     = 3,
+		y_min          = -31000,
+		y_max          = 31000,
+	})
+
+	minetest.register_ore({
+		ore_type       = "scatter",
+		ore            = "default:lava_source",
+		wherein        = "io_moon:ground_rocks",
+		clust_scarcity = 12 * 12 * 12,
+		clust_num_ores = 15,
+		clust_size     = 5,
+		y_min          = -31000,
+		y_max          = 31000,
+	})

nodes.lua

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+minetest.register_node("io_moon:stone", {
+    description = "Io Stone",
+    tiles = {"io_moon_stone.png"},
+    is_ground_content = true,
+    groups = {cracky=3},
+    sounds = default.node_sound_stone_defaults(),
+})
+
+minetest.register_node("io_moon:ground_rocks", {
+    description = "Io Ground Rocks",
+    tiles = {"io_moon_ground_rocks.png"},
+    is_ground_content = true,
+    groups = {crumbly=1, falling_node = 1},
+    sounds = default.node_sound_gravel_defaults()
+})

sky.lua

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+minetest.register_on_joinplayer(function(player)
+	minetest.after(0, function()
+		textures ={
+		"dark_sky.png",
+		"dark_sky.png",
+		"dark_sky.png",
+		"sky_neg_z.png",	
+		"dark_sky.png",
+		"dark_sky.png",
+		}
+		
+		player:set_sky({r=0, g=0, b=0, a=0},"skybox", textures)
+		player:set_clouds({density = 0})
+		
+		player:set_physics_override(1, 0.6, 0.2) -- speed, jump, gravity
+	end)
+end)