diff --git a/mods/nc_lux/fluid.lua b/mods/nc_lux/fluid.lua
index 4dcf5480..ace0d901 100644
--- a/mods/nc_lux/fluid.lua
+++ b/mods/nc_lux/fluid.lua
@@ -24,7 +24,7 @@ local wetdef = {
 	air_pass = true,
 	drowning = 0,
 	groups = {
-		lux_emit = 100,
+		lux_emit = 4,
 		lux_fluid = 1,
 		stack_as_node = 1
 	},
diff --git a/mods/nc_lux/radiation.lua b/mods/nc_lux/radiation.lua
index 165f373c..966dfdd9 100644
--- a/mods/nc_lux/radiation.lua
+++ b/mods/nc_lux/radiation.lua
@@ -1,8 +1,8 @@
 -- LUALOCALS < ---------------------------------------------------------
-local math, minetest, nodecore, pairs
-    = math, minetest, nodecore, pairs
-local math_exp, math_floor, math_log, math_sqrt
-    = math.exp, math.floor, math.log, math.sqrt
+local math, minetest, nodecore, pairs, vector
+    = math, minetest, nodecore, pairs, vector
+local math_cos, math_pi, math_random, math_sin, math_sqrt
+    = math.cos, math.pi, math.random, math.sin, math.sqrt
 -- LUALOCALS > ---------------------------------------------------------
 
 local modname = minetest.get_current_modname()
@@ -21,111 +21,187 @@ nodecore.register_healthfx({
 		end
 	})
 
-local luxaccum = {}
+---------------------------------------------------------------
 
-local function rademit(pos, emit)
-	for _, player in pairs(minetest.get_connected_players()) do
-		local pname = player:get_player_name()
-		local pp = player:get_pos()
-		pp.y = pp.y + 1
-		local dx = pp.x - pos.x
-		dx = dx * dx
-		local dy = pp.y - pos.y
-		dy = dy * dy
-		local dz = pp.z - pos.z
-		dz = dz * dz
-		local dsqr = (dx + dy + dz)
-		if dsqr > (32 * 32) then return end
-		if dsqr < 1 then
-			dsqr = 1
-		else
-			for pt in minetest.raycast(pos, pp, false, true) do
-				local pn = minetest.get_node(pt.under)
-				local def = minetest.registered_items[pn.name] or {groups = {}}
-				if def.groups.water then
-					dsqr = dsqr * 8
-				elseif pn.name ~= "air" and not def.groups.lux_emit then
-					dsqr = dsqr * 2
-				end
-				if dsqr > (32 * 32) then return end
-			end
-		end
-		luxaccum[pname] = (luxaccum[pname] or 0) + (math_log(emit) + 1) / dsqr
-	end
-end
-
-nodecore.register_limited_abm({
-		label = "lux irradiate",
-		interval = 1,
-		chance = 2,
-		nodenames = {"group:lux_emit"},
-		action = function(pos, node)
-			local def = minetest.registered_items[node.name]
-			local emit = def and def.groups and def.groups.lux_emit or 1
-			if emit then return rademit(pos, emit) end
-		end
-	})
-
-nodecore.register_aism({
-		label = "lux stack irradiate",
-		interval = 1,
-		chance = 2,
-		itemnames = {"group:lux_emit"},
-		action = function(stack, data)
-			local def = minetest.registered_items[stack:get_name()]
-			local emit = def and def.groups and def.groups.lux_emit
-			if emit then return rademit(data.pos, emit) end
-		end
-	})
-
-local avgs = {}
-nodecore.interval(1, function()
-		for _, player in pairs(minetest.get_connected_players()) do
-			local meta = player:get_meta()
-			local rad = meta:get_float("rad") or 0
-
-			local pname = player:get_player_name()
-			local accum = luxaccum[pname] or 0
-			luxaccum[pname] = 0
-
-			local prop = math_exp(-accum / 1000)
-			rad = rad * prop + (1 - prop)
-
-			local redux = 0.1
-			local pos = player:get_pos()
-			local node = minetest.get_node(pos)
-			local def = minetest.registered_items[node.name]
-			if def and def.groups and def.groups.water then
-				redux = redux + 50
-			end
-			pos.y = pos.y + 1
-			node = minetest.get_node(pos)
-			def = minetest.registered_items[node.name]
-			if def and def.groups and def.groups.water then
-				redux = redux + 500
-			end
-			prop = math_exp(-redux / 10000)
-			rad = rad * prop
-
-			meta:set_float("rad", rad)
-
-			local avg = (avgs[pname] or 0) * 0.8 + accum * 0.2
-			avgs[pname] = avg
-			local img = ""
-			if avg > 0.75 then
-				local ow = math_sqrt(avg - 0.75) * 64
-				if ow > 255 then ow = 255 end
-				img = "nc_lux_radhud.png^[opacity:" .. math_floor(ow)
-			end
-			nodecore.hud_set(player, {
-					label = "luxrad",
-					hud_elem_type = "image",
-					position = {x = 0.5, y = 0.5},
-					text = img,
-					direction = 0,
-					scale = {x = -100, y = -100},
-					offset = {x = 0, y = 0},
-					quick = true
-				})
+local rad_default = {absorb = 2/100, scatter = 2/100}
+local rad_lut = {}
+minetest.after(0, function()
+		for k, v in pairs(minetest.registered_items) do
+			local g = v.groups or {}
+			local rad = {
+				stack = g.visinv,
+				emit = g.lux_emit,
+				absorb = g.lux_absorb
+				or (v.liquidtype ~= "none" and 7/8)
+				or (g.cracky and 1 - 1 / (g.cracky + 2))
+				or (v.walkable and 1/4)
+				or rad_default.absorb,
+				scatter = g.lux_scatter
+				or (v.liquidtype ~= "none" and 1)
+				or (v.walkable and 1/8)
+				or rad_default.scatter
+			}
+			if rad.absorb < 1/100 then rad.absorb = 1/100 end
+			rad_lut[k] = rad
 		end
 	end)
+
+local function randdir()
+	-- https://math.stackexchange.com/a/44691
+	local z = math_random() * 2 - 1
+	local k = math_sqrt(1 - z * z)
+	local theta = math_random() * math_pi * 2
+	return {
+		x = k * math_cos(theta),
+		y = k * math_sin(theta),
+		z = z
+	}
+end
+
+local function radscan(player)
+	local emit = 0
+	local pos = player:get_pos()
+	pos.y = pos.y + player:get_properties().eye_height
+	local dir
+	for _ = 1, 32 do
+		local nn = minetest.get_node(pos).name
+		if nn == "ignore" then break end
+		local rad = rad_lut[nn] or rad_default
+		if rad.emit then emit = emit + rad.emit end
+		if math_random() < rad.absorb then break end
+		if math_random() < rad.scatter then dir = randdir() end
+		dir = dir or randdir()
+		pos = vector.add(pos, vector.multiply(dir, math_random() + 0.5))
+	end
+	if emit > 0 then minetest.log(nodecore.gametime .. " " .. emit) end
+end
+
+local cost = 0
+nodecore.interval(5, function()
+		minetest.chat_send_all("cost " .. (cost / 5000000))
+		cost = 0
+	end)
+nodecore.register_playerstep({
+		label = "lux rad scan",
+		action = function(player, data, dtime)
+			local start = minetest.get_us_time()
+			data.radtime = (data.radtime or 0) + dtime
+			if data.radtime > 1 then data.radtime = 1 end
+			while data.radtime > 1/16 do
+				data.radtime = data.radtime - 1/16
+				radscan(player, data)
+			end
+			cost = cost + minetest.get_us_time() - start
+		end
+	})
+
+---------------------------------------------------------------
+
+-- local luxaccum = {}
+
+-- local function rademit(pos, emit)
+-- for _, player in pairs(minetest.get_connected_players()) do
+-- local pname = player:get_player_name()
+-- local pp = player:get_pos()
+-- pp.y = pp.y + 1
+-- local dx = pp.x - pos.x
+-- dx = dx * dx
+-- local dy = pp.y - pos.y
+-- dy = dy * dy
+-- local dz = pp.z - pos.z
+-- dz = dz * dz
+-- local dsqr = (dx + dy + dz)
+-- if dsqr > (32 * 32) then return end
+-- if dsqr < 1 then
+-- dsqr = 1
+-- else
+-- for pt in minetest.raycast(pos, pp, false, true) do
+-- local pn = minetest.get_node(pt.under)
+-- local def = minetest.registered_items[pn.name] or {groups = {}}
+-- if def.groups.water then
+-- dsqr = dsqr * 8
+-- else if pn.name ~= "air" and not def.groups.lux_emit then
+-- dsqr = dsqr * 2
+-- end
+-- if dsqr > (32 * 32) then return end
+-- end
+-- end
+-- luxaccum[pname] = (luxaccum[pname] or 0) + (math_log(emit) + 1) / dsqr
+-- end
+-- end
+
+-- nodecore.register_limited_abm({
+-- label = "lux irradiate",
+-- interval = 1,
+-- chance = 2,
+-- nodenames = {"group:lux_emit"},
+-- action = function(pos, node)
+-- local def = minetest.registered_items[node.name]
+-- local emit = def and def.groups and def.groups.lux_emit or 1
+-- if emit then return rademit(pos, emit) end
+-- end
+-- })
+
+-- nodecore.register_aism({
+-- label = "lux stack irradiate",
+-- interval = 1,
+-- chance = 2,
+-- itemnames = {"group:lux_emit"},
+-- action = function(stack, data)
+-- local def = minetest.registered_items[stack:get_name()]
+-- local emit = def and def.groups and def.groups.lux_emit
+-- if emit then return rademit(data.pos, emit) end
+-- end
+-- })
+
+-- local avgs = {}
+-- nodecore.interval(1, function()
+-- for _, player in pairs(minetest.get_connected_players()) do
+-- local meta = player:get_meta()
+-- local rad = meta:get_float("rad") or 0
+
+-- local pname = player:get_player_name()
+-- local accum = luxaccum[pname] or 0
+-- luxaccum[pname] = 0
+
+-- local prop = math_exp(-accum / 1000)
+-- rad = rad * prop + (1 - prop)
+
+-- local redux = 0.1
+-- local pos = player:get_pos()
+-- local node = minetest.get_node(pos)
+-- local def = minetest.registered_items[node.name]
+-- if def and def.groups and def.groups.water then
+-- redux = redux + 50
+-- end
+-- pos.y = pos.y + 1
+-- node = minetest.get_node(pos)
+-- def = minetest.registered_items[node.name]
+-- if def and def.groups and def.groups.water then
+-- redux = redux + 500
+-- end
+-- prop = math_exp(-redux / 10000)
+-- rad = rad * prop
+
+-- meta:set_float("rad", rad)
+
+-- local avg = (avgs[pname] or 0) * 0.8 + accum * 0.2
+-- avgs[pname] = avg
+-- local img = ""
+-- if avg > 0.75 then
+-- local ow = math_sqrt(avg - 0.75) * 64
+-- if ow > 255 then ow = 255 end
+-- img = "nc_lux_radhud.png^[opacity:" .. math_floor(ow)
+-- end
+-- nodecore.hud_set(player, {
+-- label = "luxrad",
+-- hud_elem_type = "image",
+-- position = {x = 0.5, y = 0.5},
+-- text = img,
+-- direction = 0,
+-- scale = {x = -100, y = -100},
+-- offset = {x = 0, y = 0},
+-- quick = true
+-- })
+-- end
+-- end)