diff --git a/description.txt b/description.txt
new file mode 100644
index 0000000..40a2ac7
--- /dev/null
+++ b/description.txt
@@ -0,0 +1 @@
+A mapgen mod that allows any image to be used as a heightmap. If the image is not grayscale then the red channel is used. A tool is provided to change settings in-game.
diff --git a/init.lua b/init.lua
index 4dad969..a8ffac6 100644
--- a/init.lua
+++ b/init.lua
@@ -1,25 +1,28 @@
+local realterrain = {}
 local ie = minetest.request_insecure_environment()
 ie.require "luarocks.loader"
 local imlib2 = ie.require "imlib2"
 
 -- Parameters
 local DEM = 'mandelbrot16bit.tif'
-local COVER = 'cover.tif'
+local COVER = 'cover.tif' --cover should only be an 8-bit file of the same dimensions as the DEM
 
-local VERSCA = 5 -- Vertical scale, meters per node
-local YWATER = 1
+realterrain.settings = {} --form persistence
+
+--defaults
+realterrain.settings.yscale = 1
+realterrain.settings.xscale = 1
+realterrain.settings.zscale = 1
+realterrain.settings.waterlevel = 0
 
-offset = 0 --will be populated by ImageSize()
---local ImageSize = dofile(minetest.get_modpath("realterrain").."/lua-imagesize-1.2/imagesize.lua")
 local demfilename = minetest.get_modpath("realterrain").."/dem/"..DEM
---local width, length, format = ImageSize.imgsize(demfilename)
 local dem = imlib2.image.load(demfilename)
 local width = dem:get_width()
 local length = dem:get_height()
 print("width: "..width..", height: "..length)
 
---open the river tif with no safety checks
-covertiff = io.open(minetest.get_modpath("realterrain").."/dem/"..COVER, "rb")
+local coverfilename = minetest.get_modpath("realterrain").."/dem/"..COVER
+local cover = imlib2.image.load(coverfilename)
 
 -- Set mapgen parameters
 
@@ -63,7 +66,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 		local elev, cover = get_pixel(x, z) -- elevation in meters from DEM and water true/false
 				-- use demi to get elevation value from flat array
 
-		local node_elev = math.floor(YWATER + elev / VERSCA)
+		local node_elev = math.floor(tonumber(realterrain.settings.waterlevel) + elev / tonumber(realterrain.settings.yscale))
 		local vi = area:index(x, y0, z) -- voxelmanip index
 		for y = y0, y1 do
 			if y < node_elev then
@@ -76,7 +79,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 				elseif cover > 128 then 
 					data[vi] = c_stone
 				else
-					if y <= YWATER then
+					if y <= tonumber(realterrain.settings.waterlevel) then
 						data[vi] = c_sand
 					else
 						if y > 100 then 
@@ -86,7 +89,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 						end
 					end
 				end
-			elseif y <= YWATER then
+			elseif y <= tonumber(realterrain.settings.waterlevel) then
 				data[vi] = c_water
 			end
 			vi = vi + ystridevm
@@ -108,17 +111,159 @@ end)
 --and a header offset of
 
 function get_pixel(x,z)
-	if x > math.ceil(width  / 2) or x < - math.floor(width  / 2)
-	or z > math.ceil(length / 2) or z < - math.floor(length / 2) then
-		--print ("out of range of tiff")
-		return -1, 0 --off the TIFF,
+    --local row = math.floor(length / 2) + (z / tonumber(realterrain.settings.zscale))
+	--local col = math.floor(width  / 2) + (x / tonumber(realterrain.settings.xscale))
+    local row,col = 0+x, 0-z
+	local elev = dem:get_pixel(math.floor(col / tonumber(realterrain.settings.xscale)), math.floor(row / tonumber(realterrain.settings.zscale)))
+    local cover = cover:get_pixel(math.floor(col / tonumber(realterrain.settings.xscale)), math.floor(row / tonumber(realterrain.settings.zscale)))
+	return elev.red, cover.red
+end
+
+-- the controller for changing map settings
+minetest.register_tool("realterrain:remote" , {
+	description = "Realterrain Settings",
+	inventory_image = "remote.png",
+	--left-clicking the tool
+	on_use = function (itemstack, user, pointed_thing)
+        local pname = user:get_player_name()
+		realterrain.show_rc_form(pname)
+	end,
+})
+
+-- Processing the form from the RC
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if string.sub(formname, 1, 12) == "realterrain:" then
+		local wait = os.clock()
+		while os.clock() - wait < 0.05 do end --popups don't work without this see issue #30
+		print("fields submitted: "..dump(fields))
+		local pname = player:get_player_name()
+		
+		-- always save any form fields
+		for k,v in next, fields do
+			realterrain.settings[k] = v --we will preserve field entries exactly as entered 
+		end
+		realterrain.save_settings()
+		if formname == "realterrain:popup" then
+			if fields.exit == "Back" then
+				realterrain.show_rc_form(pname)
+				return true
+			end
+		end
+		
+		--the main form
+		if formname == "realterrain:rc_form" then 
+			--actual form submissions
+			if fields.exit == "Delete" then
+                minetest.chat_send_player(pname, "You changed mapgen settings and are deleting the current map, restart the world!")
+                --kick all other players
+                
+                --delete the map.sqlite file
+                
+                --kick this player? @todo what if this is a dedicated server?
+                
+                return true
+            elseif fields.exit == "Apply" then
+                minetest.chat_send_player(pname, "You changed the mapgen settings!")
+                return true
+			end
+			return true
+		end
+		return true
 	end
+end)
+--the formspecs and related settings and functions / selected field variables
+
+--called at each form submission
+function realterrain.save_settings()
+	local file = io.open(minetest.get_worldpath().."/realterrain_settings", "w")
+	if file then
+		for k,v in next, realterrain.settings do
+			local line = {key=k, values=v}
+			file:write(minetest.serialize(line).."\n")
+		end
+		file:close()
+	end
+end
+-- load settings run at EOF at mod start
+function realterrain.load_settings()
+	local file = io.open(minetest.get_worldpath().."/realterrain_settings", "r")
+	if file then
+		for line in file:lines() do
+			if line ~= "" then
+				local tline = minetest.deserialize(line)
+				realterrain.settings[tline.key] = tline.values
+			end
+		end
+		file:close()
+	end
+end
+--retrieve individual form field
+function realterrain.get_setting(setting)
+	if realterrain.settings ~= {} then
+		if realterrain.settings[setting] then
+			if realterrain.settings[setting] ~= "" then
+				return realterrain.settings[setting]
+			else
+				return false
+			end
+		else
+			return false
+		end
+	else
+		return false
+	end
+end
+-- show the main remote control form
+function realterrain.show_rc_form(pname)
+	local player = minetest.get_player_by_name(pname)
+	local ppos = player:getpos()
+	local degree = player:get_look_yaw()*180/math.pi - 90
+	if degree < 0 then degree = degree + 360 end
+	local dir
+	if     degree <= 45 or degree > 315 then dir = "North"
+	elseif degree <= 135 then dir = "West"
+	elseif degree <= 225 then dir = "South"
+	else   dir = "South" end
 	
-	local row = math.floor(length / 2) + z
-	local col = math.floor(width  / 2) + x
-	local pixel = dem:get_pixel(row,col)
-    --print(pixel.red)
-    --demtiff:seek("set", ( offset + (row * width) + col ))
-	covertiff:seek("set", ( offset + (row * width) + col ))
-	return pixel.red, 0
-end
\ No newline at end of file
+	local yscale = realterrain.get_setting("yscale")
+	local xscale = realterrain.get_setting("xscale")
+	local zscale = realterrain.get_setting("zscale")
+	local waterlevel = realterrain.get_setting("waterlevel")
+	
+    --form header
+	local f_header = 			"size[12,10]" ..
+								--"tabheader[0,0;tab;1D, 2D, 3D, Import, Manage;"..tab.."]"..
+								"label[0,0;You are at x= "..math.floor(ppos.x)..
+								" y= "..math.floor(ppos.y).." z= "..math.floor(ppos.z).." and mostly facing "..dir.."]"
+	--Scale settings
+	local f_scale_settings =    "field[1,4;4,1;yscale;Vertical Scale;"..minetest.formspec_escape(yscale).."]" ..
+                                "field[1,5;4,1;xscale;East-West Scale;"..minetest.formspec_escape(xscale).."]" ..
+								"field[1,6;4,1;zscale;North-South Scale;"..minetest.formspec_escape(zscale).."]" ..
+								"field[1,7;4,1;waterlevel;Water Level;"..minetest.formspec_escape(waterlevel).."]"
+	--Action buttons
+	local f_footer = 			"label[3,8.5;Delete the map, reset]"..
+								"button_exit[3,9;2,1;exit;Delete]"..
+                                "label[7,8.5;Reset the map only]"..
+								"button_exit[7,9;2,1;exit;Apply]"
+    
+    minetest.show_formspec(pname, "realterrain:rc_form", 
+                        f_header ..
+                        f_scale_settings ..
+                        f_footer
+    )
+    return true
+end
+
+-- this is the form-error popup
+function realterrain.show_popup(pname, message)
+	minetest.chat_send_player(pname, "Form error: ".. message)
+	minetest.show_formspec(pname,   "realterrain:popup",
+                                    "size[10,8]" ..
+                                    "button_exit[1,1;2,1;exit;Back]"..
+                                    "label[1,3;"..minetest.formspec_escape(message).."]"
+	)
+	return true
+end
+
+--read from file, various persisted settings
+realterrain.load_settings()
\ No newline at end of file
diff --git a/screenshot.png b/screenshot.png
new file mode 100644
index 0000000..05e5517
Binary files /dev/null and b/screenshot.png differ
diff --git a/textures/remote.png b/textures/remote.png
new file mode 100644
index 0000000..3c7dfef
Binary files /dev/null and b/textures/remote.png differ