diff --git a/README.md b/README.md
index 0714078..0d62ac0 100644
--- a/README.md
+++ b/README.md
@@ -18,4 +18,5 @@ If you got ideas or found bugs, please tell them to me.
 
 
 TODO:  
-— find a way to get the perlin noise inside [-1; 1] or use another noise
+— find a way to get the perlin noise inside [-1; 1] or use another noise  
+— add something containing items to that buildings
diff --git a/nether/pearl.lua b/nether/pearl.lua
index 25dfac2..2fcd674 100644
--- a/nether/pearl.lua
+++ b/nether/pearl.lua
@@ -7,36 +7,60 @@ local function table_contains(t, v)
 	return false
 end
 
-local teleportball_player
+local creative = minetest.setting_getbool("creative_mode")
 local function throw_pearl(item, player)
 	local playerpos = player:getpos()
-	local obj = minetest.add_entity({x=playerpos.x,y=playerpos.y+1.625,z=playerpos.z}, "nether:pearl_entity")
+	playerpos.y = playerpos.y+1.625
+	local obj = minetest.add_entity(playerpos, "nether:pearl_entity")
 	local dir = player:get_look_dir()
-	obj:setvelocity({x=dir.x*30, y=dir.y*30, z=dir.z*30})
+	obj:setvelocity(vector.multiply(dir, 30))
 	obj:setacceleration({x=dir.x*-3, y=-dir.y^8*80-10, z=dir.z*-3})
-	if not minetest.setting_getbool("creative_mode") then
+	obj:get_luaentity().player = player:get_player_name()
+	if not creative then
 		item:take_item()
+		return item
 	end
-	teleportball_player = player
-	return item
 end
 
-local ENTITY = {
-	timer=0,
-	collisionbox = {0,0,0,0,0,0}, --not pointable
-	physical = false, -- Collides with things
-	textures = {"nether_pearl.png"},
-	lastpos={},
-	player = "",
-}
+local function get_node(pos)
+	local name = minetest.get_node(pos).name
+	if name == "ignore" then
+		minetest.get_voxel_manip():read_from_map(pos, pos)
+		name = minetest.get_node_or_nil(pos)
+		if not name then
+			return
+		end
+		name = name.name
+	end
+	return name
+end
 
-local allowed_nodes = {"air", "default:water_source"}
+local softs = {}
+local function is_soft(pos)
+	local name = get_node(pos)
+	if not name then
+		return false
+	end
+	local is_soft = softs[name]
+	if is_soft ~= nil then
+		return is_soft
+	end
+	if not minetest.registered_nodes[name] then
+		softs[name] = false
+		return false
+	end
+	is_soft = minetest.registered_nodes[name].walkable == false
+	softs[name] = is_soft
+	return is_soft
+end
+
+-- teleports the player there if there's free space
 local function teleport_player(pos, player)
-	local nd2 = minetest.get_node(pos).name
+	local nd2 = is_soft(pos)
 	pos.y = pos.y+1
-	local nd3 = minetest.get_node(pos).name
-	if table_contains(allowed_nodes, nd2)
-	and table_contains(allowed_nodes, nd3) then
+	local nd3 = is_soft(pos)
+	if nd2
+	and nd3 then
 		pos.y = pos.y-1.4
 		player:moveto(pos)
 		pos.y = pos.y-0.6
@@ -45,70 +69,130 @@ local function teleport_player(pos, player)
 	return false
 end
 
-ENTITY.on_step = function(self, dtime)
-	self.timer=self.timer+dtime
+--[[
+local dg_ps = {}
+local function forceload(pos)
+	dg_ps[#dg_ps+1] = pos
+	minetest.forceload_block(pos)
+	minetest.after(5, function(pos)
+		minetest.forceload_free_block(pos)
+		for i,p in pairs(dg_ps) do
+			if vector.equals(p, pos) then
+				dg_ps[i] = nil
+				return
+			end
+		end
+	end, pos)
+end
+minetest.register_on_shutdown(function()
+	for _,p in pairs(dg_ps) do
+		minetest.forceload_free_block(p)
+	end
+end)--]]
+
+minetest.register_entity("nether:pearl_entity", {
+	timer = 0,
+	collisionbox = {0,0,0,0,0,0}, --not pointable
+	physical = false, -- Collides with things
+	textures = {"nether_pearl.png"},
+	on_activate = function(self, staticdata)
+		if not staticdata
+		or staticdata == "" then
+			return
+		end
+		local tmp = minetest.deserialize(staticdata)
+		if not tmp then
+			minetest.log("error", "[nether] pearl: invalid staticdata ")
+			return
+		end
+		self.player = tmp.player
+	end,
+	get_staticdata = function(self)
+		--forceload(vector.round(self.object:getpos()))
+		return minetest.serialize({
+			player = self.player,
+		})
+	end,
+	on_step = function(self, dtime)
+		self.timer = self.timer+dtime
+
+	--[[
+		local delay = self.delay
+		if delay < 0.1 then
+			self.delay = delay+dtime
+			return
+		end
+		self.delay = 0--]]
+
+		if self.timer > 20 then
+			self.object:remove()
+			return
+		end
+
+		local pos = self.object:getpos()
+		local rpos = vector.round(pos)
+		local lastpos = self.lastpos
+		if not lastpos then
+			self.lastpos = vector.new(rpos)
+			return
+		end
+		if lastpos.x
+		and vector.equals(vector.round(lastpos), rpos) then
+			return
+		end
+
+		local player = self.player
+		if not player then
+			minetest.log("error", "[nether] pearl: missing playername")
+			self.object:remove()
+			return
+		end
+		player = minetest.get_player_by_name(player)
+		if not player then
+			minetest.log("error", "[nether] pearl: missing player")
+			self.object:remove()
+			return
+		end
+
+		if not get_node(rpos) then
+			minetest.log("error", "[nether] pearl: missing node")
+			self.object:remove()
+			return
+		end
+
+		self.lastpos = vector.new(pos)
 
---[[	local delay = self.delay
-	if delay < 0.1 then
-		self.delay = delay+dtime
-		return
-	end
-	self.delay = 0]]
-	local pos = self.object:getpos()
-	local lastpos = self.lastpos
-	if lastpos.x
-	and vector.equals(vector.round(lastpos), vector.round(pos)) then
-		return
-	end
-	local player = self.player
-	if not player
-	or player == "" then
-		self.player = teleportball_player
-		player = teleportball_player
-	end
-	if not player then
-		self.object:remove()
-		return
-	end
-	if lastpos.x then --If there is no lastpos for some reason.
 		local free, p = minetest.line_of_sight(lastpos, pos)
-		if not free then
-			local nd1 = minetest.get_node(p).name
-			if not table_contains(allowed_nodes, nd1)
-			and nd1 ~= "ignore" then
-				self.object:remove()
-				minetest.after(0, function(p) --minetest.after us used that the sound is played after the teleportation
-					minetest.sound_play("nether_pearl", {pos=p, max_hear_distance=10})
-				end, p)
-				p.y = p.y+1
-				if teleport_player(p, player) then
+		if free then
+			return
+		end
+		if is_soft(p) then
+			return
+		end
+		self.object:remove()
+		minetest.after(0, function(p) --minetest.after is used that the sound is played after the teleportation
+			minetest.sound_play("nether_pearl", {pos=p, max_hear_distance=10})
+		end, p)
+		p.y = p.y+1
+		if teleport_player(p, player) then
+			return
+		end
+		p.y = p.y-2
+		for i = -1,1,2 do
+			for _,j in pairs({{i, 0}, {0, i}}) do
+				if teleport_player({x=p.x+j[1], y=p.y, z=p.z+j[2]}, player) then
 					return
 				end
-				p.y = p.y-2
-				for i = -1,1,2 do
-					for _,j in pairs({{i, 0}, {0, i}}) do
-						if teleport_player({x=p.x+j[1], y=p.y, z=p.z+j[2]}, player) then
-							return
-						end
-					end
-				end
-				for i = -1,1,2 do
-					for j = -1,1,2 do
-						if teleport_player({x=p.x+j, y=p.y, z=p.z+i}, player) then
-							return
-						end
-					end
+			end
+		end
+		for i = -1,1,2 do
+			for j = -1,1,2 do
+				if teleport_player({x=p.x+j, y=p.y, z=p.z+i}, player) then
+					return
 				end
 			end
 		end
 	end
-	if self.timer > 20 then
-		self.object:remove()
-		return
-	end
-	self.lastpos = vector.new(pos)
-end
-
-minetest.register_entity("nether:pearl_entity", ENTITY)
+})
 
 minetest.override_item("nether:pearl", {on_use = throw_pearl})
diff --git a/nether/portal.lua b/nether/portal.lua
index ab75ab7..3d5a64a 100644
--- a/nether/portal.lua
+++ b/nether/portal.lua
@@ -3,7 +3,7 @@
 -- kills the player if he uses PilzAdam portal
 local obsidian_portal_kills = true
 local portal_target = nether.buildings+1
-local damage_enabled = minetest.setting_getbool("enable_damage")
+local nether_prisons = minetest.setting_getbool("enable_damage")
 
 local abm_allowed
 minetest.after(5, function()
@@ -40,7 +40,7 @@ local function save_nether_players()
 end
 
 local update_background
-if damage_enabled then
+if nether_prisons then
 	function update_background(player, down)
 		if down then
 			player:set_sky({r=15, g=0, b=0}, "plain")
@@ -84,372 +84,372 @@ local function player_from_nether(player)
 end
 
 
-if damage_enabled then
-local function player_exists(name)
-	for _,player in pairs(minetest.get_connected_players()) do
-		if player:get_player_name() == name then
-			return true
+if nether_prisons then
+	local function player_exists(name)
+		for _,player in pairs(minetest.get_connected_players()) do
+			if player:get_player_name() == name then
+				return true
+			end
 		end
+		return false
 	end
-	return false
-end
 
--- Chatcommands (edited) written by sss
-minetest.register_chatcommand("to_hell", {
-	params = "[<player_name>]",
-	description = "Send someone to hell",
-	func = function(name, pname)
-		if not minetest.check_player_privs(name, {nether=true}) then
-			return false, "You need the nether priv to execute this chatcommand."
+	-- Chatcommands (edited) written by sss
+	minetest.register_chatcommand("to_hell", {
+		params = "[<player_name>]",
+		description = "Send someone to hell",
+		func = function(name, pname)
+			if not minetest.check_player_privs(name, {nether=true}) then
+				return false, "You need the nether priv to execute this chatcommand."
+			end
+			if not player_exists(pname) then
+				pname = name
+			end
+			local player = minetest.get_player_by_name(pname)
+			if not player then
+				return false, "Something went wrong."
+			end
+			minetest.chat_send_player(pname, "Go to hell !!!")
+			player_to_nether(player)
+			return true, pname.." is now in the nether."
 		end
-		if not player_exists(pname) then
-			pname = name
-		end
-		local player = minetest.get_player_by_name(pname)
-		if not player then
-			return false, "Something went wrong."
-		end
-		minetest.chat_send_player(pname, "Go to hell !!!")
-		player_to_nether(player)
-		return true, pname.." is now in the nether."
-	end
-})
+	})
 
-minetest.register_chatcommand("from_hell", {
-	params = "[<player_name>]",
-	description = "Extract from hell",
-	func = function(name, pname)
-		if not minetest.check_player_privs(name, {nether=true}) then
-			return false, "You need the nether priv to execute this chatcommand."
+	minetest.register_chatcommand("from_hell", {
+		params = "[<player_name>]",
+		description = "Extract from hell",
+		func = function(name, pname)
+			if not minetest.check_player_privs(name, {nether=true}) then
+				return false, "You need the nether priv to execute this chatcommand."
+			end
+			if not player_exists(pname) then
+				pname = name
+			end
+			local player = minetest.get_player_by_name(pname)
+			if not player then
+				return false, "Something went wrong."
+			end
+			minetest.chat_send_player(pname, "You are free now")
+			player_from_nether(player)
+			local pos = player:getpos()
+			player:moveto({x=pos.x, y=100, z=pos.z})
+			return true, pname.." is now out of the nether."
 		end
-		if not player_exists(pname) then
-			pname = name
-		end
-		local player = minetest.get_player_by_name(pname)
-		if not player then
-			return false, "Something went wrong."
-		end
-		minetest.chat_send_player(pname, "You are free now")
-		player_from_nether(player)
-		local pos = player:getpos()
-		player:moveto({x=pos.x, y=100, z=pos.z})
-		return true, pname.." is now out of the nether."
-	end
-})
+	})
 
-minetest.register_on_respawnplayer(function(player)
-	local pname = player:get_player_name()
-	if not table.icontains(players_in_nether, pname) then
-		return
-	end
-	local target = vector.add(player:getpos(), {x=math.random(-100,100), y=0, z=math.random(-100,100)})
-	target.y = portal_target + math.random(4)
-	player:moveto(target)
-	minetest.after(0, function(pname, target)
-		local player = minetest.get_player_by_name(pname)
-		if player then
-			player:moveto(target)
-		end
-	end, pname, target)
-	return true
-end)
-
-local function update_players()
-	for _,player in ipairs(minetest.get_connected_players()) do
+	minetest.register_on_respawnplayer(function(player)
 		local pname = player:get_player_name()
-		local ppos = player:getpos()
-		if table.icontains(players_in_nether, pname) then
-			if ppos.y > nether.start then
-				player:moveto({x=ppos.x, y=portal_target, z=ppos.z})
-				update_background(player, true)
-				--[[minetest.kick_player(pname, "\n1. Maybe you were not allowed to teleport out of the nether."..
+		if not table.icontains(players_in_nether, pname) then
+			return
+		end
+		local target = vector.add(player:getpos(), {x=math.random(-100,100), y=0, z=math.random(-100,100)})
+		target.y = portal_target + math.random(4)
+		player:moveto(target)
+		minetest.after(0, function(pname, target)
+			local player = minetest.get_player_by_name(pname)
+			if player then
+				player:moveto(target)
+			end
+		end, pname, target)
+		return true
+	end)
+
+	local function update_players()
+		for _,player in ipairs(minetest.get_connected_players()) do
+			local pname = player:get_player_name()
+			local ppos = player:getpos()
+			if table.icontains(players_in_nether, pname) then
+				if ppos.y > nether.start then
+					player:moveto({x=ppos.x, y=portal_target, z=ppos.z})
+					update_background(player, true)
+					--[[minetest.kick_player(pname, "\n1. Maybe you were not allowed to teleport out of the nether."..
+						"\n2. Maybe the server lagged."..
+						"\n3. please rejoin")]]
+				end
+			elseif ppos.y < nether.start then
+				update_background(player)
+				player:moveto({x=ppos.x, y=20, z=ppos.z})
+				--[[minetest.kick_player(pname, "\n1. Maybe you were not allowed to teleport to the nether."..
 					"\n2. Maybe the server lagged."..
 					"\n3. please rejoin")]]
 			end
-		elseif ppos.y < nether.start then
-			update_background(player)
-			player:moveto({x=ppos.x, y=20, z=ppos.z})
-			--[[minetest.kick_player(pname, "\n1. Maybe you were not allowed to teleport to the nether."..
-				"\n2. Maybe the server lagged."..
-				"\n3. please rejoin")]]
 		end
 	end
-end
 
-local timer = 0	--doesn't work if the server lags
-minetest.register_globalstep(function(dtime)
-	timer = timer + dtime;
-	if timer >= 2 then
-		--minetest.after(1, update_players)
-		update_players()
-		timer = 0
-	end
-end)
-
-minetest.register_on_joinplayer(function(player)
-	minetest.after(0, function(player)
-		if player:getpos().y < nether.start then
-			update_background(player, true)
+	local timer = 0	--doesn't work if the server lags
+	minetest.register_globalstep(function(dtime)
+		timer = timer + dtime;
+		if timer >= 2 then
+			--minetest.after(1, update_players)
+			update_players()
+			timer = 0
 		end
-	end, player)
-end)
+	end)
 
-local function remove_portal_essence(pos)
-	for z = -1,1 do
-		for y = -2,2 do
-			for x = -1,1 do
-				local p = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
-				if minetest.get_node(p).name == "nether:portal" then
-					minetest.remove_node(p)
-				end
+	minetest.register_on_joinplayer(function(player)
+		minetest.after(0, function(player)
+			if player:getpos().y < nether.start then
+				update_background(player, true)
 			end
-		end
-	end
-end
+		end, player)
+	end)
 
-minetest.register_abm({
-	nodenames = {"nether:portal"},
-	interval = 1,
-	chance = 2,
-	catch_up = false,
-	action = function(pos, node)
-		if not abm_allowed then
-			return
-		end
-		minetest.add_particlespawner({
-			amount = 32,
-			time = 4,
-			minpos = {x=pos.x-0.25, y=pos.y-0.5, z=pos.z-0.25},
-			maxpos = {x=pos.x+0.25, y=pos.y+0.34, z=pos.z+0.25},
-			minvel = {x=0, y=1, z=0},
-			maxvel = {x=0, y=2, z=0},
-			minacc = {x=-0.5,y=-3,z=-0.3},
-			maxacc = {x=0.5,y=-0.4,z=0.3},
-			minexptime = 1,
-			maxexptime = 1,
-			minsize = 0.4,
-			maxsize = 3,
-			collisiondetection = true,
-			texture = "nether_portal_particle.png^[transform"..math.random(0,7),
-		})
-		for _,obj in pairs(minetest.get_objects_inside_radius(pos, 1)) do
-			if obj:is_player() then
-				local meta = minetest.get_meta(pos)
-				local target = minetest.string_to_pos(meta:get_string("target"))
-				if target then
-					minetest.after(3, function(obj, pos, target)
-						local pname = obj:get_player_name()
-						if table.icontains(players_in_nether, pname) then
-							return
-						end
-						local objpos = obj:getpos()
-						objpos.y = objpos.y+0.1 -- Fix some glitches at -8000
-						if minetest.get_node(vector.round(objpos)).name ~= "nether:portal" then
-							return
-						end
-
-						remove_portal_essence(pos)
-
-						minetest.sound_play("nether_portal_usual", {to_player=pname, gain=1})
-						player_to_nether(obj)
-						--obj:setpos(target)
-
-					end, obj, pos, target)
-				end
-			end
-		end
-	end,
-})
-
-local function move_check(p1, max, dir)
-	local p = {x=p1.x, y=p1.y, z=p1.z}
-	local d = math.abs(max-p1[dir]) / (max-p1[dir])
-	while p[dir] ~= max do
-		p[dir] = p[dir] + d
-		if minetest.get_node(p).name ~= "default:obsidian" then
-			return false
-		end
-	end
-	return true
-end
-
-local function check_portal(p1, p2)
-	if p1.x ~= p2.x then
-		if not move_check(p1, p2.x, "x") then
-			return false
-		end
-		if not move_check(p2, p1.x, "x") then
-			return false
-		end
-	elseif p1.z ~= p2.z then
-		if not move_check(p1, p2.z, "z") then
-			return false
-		end
-		if not move_check(p2, p1.z, "z") then
-			return false
-		end
-	else
-		return false
-	end
-
-	if not move_check(p1, p2.y, "y") then
-		return false
-	end
-	if not move_check(p2, p1.y, "y") then
-		return false
-	end
-
-	return true
-end
-
-local function is_portal(pos)
-	for d=-3,3 do
-		for y=-4,4 do
-			local px = {x=pos.x+d, y=pos.y+y, z=pos.z}
-			local pz = {x=pos.x, y=pos.y+y, z=pos.z+d}
-			if check_portal(px, {x=px.x+3, y=px.y+4, z=px.z}) then
-				return px, {x=px.x+3, y=px.y+4, z=px.z}
-			end
-			if check_portal(pz, {x=pz.x, y=pz.y+4, z=pz.z+3}) then
-				return pz, {x=pz.x, y=pz.y+4, z=pz.z+3}
-			end
-		end
-	end
-end
-
-local function make_portal(pos)
-	local p1, p2 = is_portal(pos)
-	if not p1
-	or not p2 then
-		print("[nether] something failed.")
-		return false
-	end
-
-	if p1.y < nether.start then
-		print("[nether] aborted, obsidian portals can't be used to get out")
-		return
-	end
-
-	for d=1,2 do
-	for y=p1.y+1,p2.y-1 do
-		local p
-		if p1.z == p2.z then
-			p = {x=p1.x+d, y=y, z=p1.z}
-		else
-			p = {x=p1.x, y=y, z=p1.z+d}
-		end
-		if minetest.get_node(p).name ~= "air" then
-			return false
-		end
-	end
-	end
-
-	local param2
-	if p1.z == p2.z then
-		param2 = 0
-	else
-		param2 = 1
-	end
-
-	local target = {x=p1.x, y=p1.y, z=p1.z}
-	target.x = target.x + 1
-	target.y = portal_target + math.random(4)
-
-	for d=0,3 do
-	for y=p1.y,p2.y do
-		local p = {}
-		if param2 == 0 then
-			p = {x=p1.x+d, y=y, z=p1.z}
-		else
-			p = {x=p1.x, y=y, z=p1.z+d}
-		end
-		if minetest.get_node(p).name == "air" then
-			minetest.set_node(p, {name="nether:portal", param2=param2})
-		end
-		local meta = minetest.get_meta(p)
-		meta:set_string("p1", minetest.pos_to_string(p1))
-		meta:set_string("p2", minetest.pos_to_string(p2))
-		meta:set_string("target", minetest.pos_to_string(target))
-	end
-	end
-	print("[nether] construction accepted.")
-	return true
-end
-
-minetest.override_item("default:obsidian", {
-	on_destruct = function(pos)
-		local meta = minetest.get_meta(pos)
-		local p1 = minetest.string_to_pos(meta:get_string("p1"))
-		local p2 = minetest.string_to_pos(meta:get_string("p2"))
-		local target = minetest.string_to_pos(meta:get_string("target"))
-		if not p1 or not p2 then
-			return
-		end
-		for x=p1.x,p2.x do
-		for y=p1.y,p2.y do
-		for z=p1.z,p2.z do
-			local nn = minetest.get_node({x=x,y=y,z=z}).name
-			if nn == "default:obsidian" or nn == "nether:portal" then
-				if nn == "nether:portal" then
-					minetest.remove_node({x=x,y=y,z=z})
-				end
-				local m = minetest.get_meta({x=x,y=y,z=z})
-				m:set_string("p1", "")
-				m:set_string("p2", "")
-				m:set_string("target", "")
-			end
-		end
-		end
-		end
-		meta = minetest.get_meta(target)
-		if not meta then
-			return
-		end
-		p1 = minetest.string_to_pos(meta:get_string("p1"))
-		p2 = minetest.string_to_pos(meta:get_string("p2"))
-		if not p1 or not p2 then
-			return
-		end
-		for x=p1.x,p2.x do
-		for y=p1.y,p2.y do
-		for z=p1.z,p2.z do
-			local nn = minetest.get_node({x=x,y=y,z=z}).name
-			if nn == "default:obsidian" or nn == "nether:portal" then
-				if nn == "nether:portal" then
-					minetest.remove_node({x=x,y=y,z=z})
-				end
-				local m = minetest.get_meta({x=x,y=y,z=z})
-				m:set_string("p1", "")
-				m:set_string("p2", "")
-				m:set_string("target", "")
-			end
-		end
-		end
-		end
-	end
-})
-
-minetest.after(0.1, function()
-	minetest.override_item("default:mese_crystal_fragment", {
-		on_place = function(stack, player, pt)
-			if pt.under
-			and minetest.get_node(pt.under).name == "default:obsidian" then
-				print("[nether] tries to enable a portal")
-				local done = make_portal(pt.under)
-				if done then
-					minetest.chat_send_player(
-						player:get_player_name(),
-						"Warning: If you are in the nether you may not be able to find the way out!"
-					)
-					if not minetest.setting_getbool("creative_mode") then
-						stack:take_item()
+	local function remove_portal_essence(pos)
+		for z = -1,1 do
+			for y = -2,2 do
+				for x = -1,1 do
+					local p = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
+					if minetest.get_node(p).name == "nether:portal" then
+						minetest.remove_node(p)
 					end
 				end
 			end
-			return stack
+		end
+	end
+
+	minetest.register_abm({
+		nodenames = {"nether:portal"},
+		interval = 1,
+		chance = 2,
+		catch_up = false,
+		action = function(pos, node)
+			if not abm_allowed then
+				return
+			end
+			minetest.add_particlespawner({
+				amount = 32,
+				time = 4,
+				minpos = {x=pos.x-0.25, y=pos.y-0.5, z=pos.z-0.25},
+				maxpos = {x=pos.x+0.25, y=pos.y+0.34, z=pos.z+0.25},
+				minvel = {x=0, y=1, z=0},
+				maxvel = {x=0, y=2, z=0},
+				minacc = {x=-0.5,y=-3,z=-0.3},
+				maxacc = {x=0.5,y=-0.4,z=0.3},
+				minexptime = 1,
+				maxexptime = 1,
+				minsize = 0.4,
+				maxsize = 3,
+				collisiondetection = true,
+				texture = "nether_portal_particle.png^[transform"..math.random(0,7),
+			})
+			for _,obj in pairs(minetest.get_objects_inside_radius(pos, 1)) do
+				if obj:is_player() then
+					local meta = minetest.get_meta(pos)
+					local target = minetest.string_to_pos(meta:get_string("target"))
+					if target then
+						minetest.after(3, function(obj, pos, target)
+							local pname = obj:get_player_name()
+							if table.icontains(players_in_nether, pname) then
+								return
+							end
+							local objpos = obj:getpos()
+							objpos.y = objpos.y+0.1 -- Fix some glitches at -8000
+							if minetest.get_node(vector.round(objpos)).name ~= "nether:portal" then
+								return
+							end
+
+							remove_portal_essence(pos)
+
+							minetest.sound_play("nether_portal_usual", {to_player=pname, gain=1})
+							player_to_nether(obj)
+							--obj:setpos(target)
+
+						end, obj, pos, target)
+					end
+				end
+			end
+		end,
+	})
+
+	local function move_check(p1, max, dir)
+		local p = {x=p1.x, y=p1.y, z=p1.z}
+		local d = math.abs(max-p1[dir]) / (max-p1[dir])
+		while p[dir] ~= max do
+			p[dir] = p[dir] + d
+			if minetest.get_node(p).name ~= "default:obsidian" then
+				return false
+			end
+		end
+		return true
+	end
+
+	local function check_portal(p1, p2)
+		if p1.x ~= p2.x then
+			if not move_check(p1, p2.x, "x") then
+				return false
+			end
+			if not move_check(p2, p1.x, "x") then
+				return false
+			end
+		elseif p1.z ~= p2.z then
+			if not move_check(p1, p2.z, "z") then
+				return false
+			end
+			if not move_check(p2, p1.z, "z") then
+				return false
+			end
+		else
+			return false
+		end
+
+		if not move_check(p1, p2.y, "y") then
+			return false
+		end
+		if not move_check(p2, p1.y, "y") then
+			return false
+		end
+
+		return true
+	end
+
+	local function is_portal(pos)
+		for d=-3,3 do
+			for y=-4,4 do
+				local px = {x=pos.x+d, y=pos.y+y, z=pos.z}
+				local pz = {x=pos.x, y=pos.y+y, z=pos.z+d}
+				if check_portal(px, {x=px.x+3, y=px.y+4, z=px.z}) then
+					return px, {x=px.x+3, y=px.y+4, z=px.z}
+				end
+				if check_portal(pz, {x=pz.x, y=pz.y+4, z=pz.z+3}) then
+					return pz, {x=pz.x, y=pz.y+4, z=pz.z+3}
+				end
+			end
+		end
+	end
+
+	local function make_portal(pos)
+		local p1, p2 = is_portal(pos)
+		if not p1
+		or not p2 then
+			print("[nether] something failed.")
+			return false
+		end
+
+		if p1.y < nether.start then
+			print("[nether] aborted, obsidian portals can't be used to get out")
+			return
+		end
+
+		for d=1,2 do
+		for y=p1.y+1,p2.y-1 do
+			local p
+			if p1.z == p2.z then
+				p = {x=p1.x+d, y=y, z=p1.z}
+			else
+				p = {x=p1.x, y=y, z=p1.z+d}
+			end
+			if minetest.get_node(p).name ~= "air" then
+				return false
+			end
+		end
+		end
+
+		local param2
+		if p1.z == p2.z then
+			param2 = 0
+		else
+			param2 = 1
+		end
+
+		local target = {x=p1.x, y=p1.y, z=p1.z}
+		target.x = target.x + 1
+		target.y = portal_target + math.random(4)
+
+		for d=0,3 do
+		for y=p1.y,p2.y do
+			local p = {}
+			if param2 == 0 then
+				p = {x=p1.x+d, y=y, z=p1.z}
+			else
+				p = {x=p1.x, y=y, z=p1.z+d}
+			end
+			if minetest.get_node(p).name == "air" then
+				minetest.set_node(p, {name="nether:portal", param2=param2})
+			end
+			local meta = minetest.get_meta(p)
+			meta:set_string("p1", minetest.pos_to_string(p1))
+			meta:set_string("p2", minetest.pos_to_string(p2))
+			meta:set_string("target", minetest.pos_to_string(target))
+		end
+		end
+		print("[nether] construction accepted.")
+		return true
+	end
+
+	minetest.override_item("default:obsidian", {
+		on_destruct = function(pos)
+			local meta = minetest.get_meta(pos)
+			local p1 = minetest.string_to_pos(meta:get_string("p1"))
+			local p2 = minetest.string_to_pos(meta:get_string("p2"))
+			local target = minetest.string_to_pos(meta:get_string("target"))
+			if not p1 or not p2 then
+				return
+			end
+			for x=p1.x,p2.x do
+			for y=p1.y,p2.y do
+			for z=p1.z,p2.z do
+				local nn = minetest.get_node({x=x,y=y,z=z}).name
+				if nn == "default:obsidian" or nn == "nether:portal" then
+					if nn == "nether:portal" then
+						minetest.remove_node({x=x,y=y,z=z})
+					end
+					local m = minetest.get_meta({x=x,y=y,z=z})
+					m:set_string("p1", "")
+					m:set_string("p2", "")
+					m:set_string("target", "")
+				end
+			end
+			end
+			end
+			meta = minetest.get_meta(target)
+			if not meta then
+				return
+			end
+			p1 = minetest.string_to_pos(meta:get_string("p1"))
+			p2 = minetest.string_to_pos(meta:get_string("p2"))
+			if not p1 or not p2 then
+				return
+			end
+			for x=p1.x,p2.x do
+			for y=p1.y,p2.y do
+			for z=p1.z,p2.z do
+				local nn = minetest.get_node({x=x,y=y,z=z}).name
+				if nn == "default:obsidian" or nn == "nether:portal" then
+					if nn == "nether:portal" then
+						minetest.remove_node({x=x,y=y,z=z})
+					end
+					local m = minetest.get_meta({x=x,y=y,z=z})
+					m:set_string("p1", "")
+					m:set_string("p2", "")
+					m:set_string("target", "")
+				end
+			end
+			end
+			end
 		end
 	})
-end)
+
+	minetest.after(0.1, function()
+		minetest.override_item("default:mese_crystal_fragment", {
+			on_place = function(stack, player, pt)
+				if pt.under
+				and minetest.get_node(pt.under).name == "default:obsidian" then
+					print("[nether] tries to enable a portal")
+					local done = make_portal(pt.under)
+					if done then
+						minetest.chat_send_player(
+							player:get_player_name(),
+							"Warning: If you are in the nether you may not be able to find the way out!"
+						)
+						if not minetest.setting_getbool("creative_mode") then
+							stack:take_item()
+						end
+					end
+				end
+				return stack
+			end
+		})
+	end)
 end