diff --git a/README.md b/README.md
index c910077..6080877 100644
--- a/README.md
+++ b/README.md
@@ -2,18 +2,20 @@
 
 This mod adds mushrooms to minetest. The growing tool can make them giant.
 
-**Depends:** see [depends.txt](https://raw.githubusercontent.com/HybridDog/riesenpilz/master/depends.txt)  
-**License:** see [LICENSE.txt](https://raw.githubusercontent.com/HybridDog/riesenpilz/master/LICENSE.txt)  
-**Download:** [zip](https://github.com/HybridDog/riesenpilz/archive/master.zip), [tar.gz](https://github.com/HybridDog/riesenpilz/archive/master.tar.gz)  
+**Depends:** see [depends.txt](https://raw.githubusercontent.com/HybridDog/riesenpilz/master/depends.txt)<br/>
+**License:** see [LICENSE.txt](https://raw.githubusercontent.com/HybridDog/riesenpilz/master/LICENSE.txt)<br/>
+**Download:** [zip](https://github.com/HybridDog/riesenpilz/archive/master.zip), [tar.gz](https://github.com/HybridDog/riesenpilz/archive/master.tar.gz)<br/>
 
 ![I'm a screenshot!](https://cloud.githubusercontent.com/assets/3192173/5332059/421c735a-7e47-11e4-88cc-b9ed90b659a8.png)
 
 If you got ideas or found bugs, please tell them to me.
 
 
-TODO:  
-— add more giant mushrooms  
-— finish supporting the mushrooms mod  
-— add lava suit  
-— use visual_scale → crop textures and change nodeboxes (maybe automatically)  
-— make the growingtool craftable
+TODO:
+* add more giant mushrooms
+* finish supporting the mushrooms mod
+* add lava suit
+* use visual_scale → crop textures and change nodeboxes (maybe automatically)
+* make the growingtool craftable
+* mapgen: do not use fixed tree stuff
+* add settingtypes.txt
diff --git a/mapgen.lua b/mapgen.lua
index 4c8bfbb..184c510 100644
--- a/mapgen.lua
+++ b/mapgen.lua
@@ -77,7 +77,8 @@ function is_toremove(id)
 end
 
 
-local data, area, pr
+local data = {}
+local area, pr
 function riesenpilz_circle(nam, pos, radius, chance)
 	local circle = vector.circle(radius)
 	for i = 1,#circle do
@@ -92,25 +93,11 @@ function riesenpilz_circle(nam, pos, radius, chance)
 end
 
 
--- perlin noise "hills" are not peaks but looking like sinus curve
-local function upper_rarity(rarity)
-	return math.sign(rarity)*math.sin(math.abs(rarity)*math.pi/2)
-end
-
-local rarity = riesenpilz.mapgen_rarity
-local riesenpilz_size = riesenpilz.mapgen_size
-
-local nosmooth_rarity = 1-rarity/50
-local perlin_scale = riesenpilz_size*100/rarity
-local smooth_rarity_max, smooth_rarity_min, smooth_rarity_dif
-local smooth = riesenpilz.smooth
-if smooth then
-	local smooth_trans_size = riesenpilz.smooth_trans_size
-	smooth_rarity_max = upper_rarity(nosmooth_rarity+smooth_trans_size*2/perlin_scale)
-	smooth_rarity_min = upper_rarity(nosmooth_rarity-smooth_trans_size/perlin_scale)
-	smooth_rarity_dif = smooth_rarity_max-smooth_rarity_min
-end
-nosmooth_rarity = upper_rarity(nosmooth_rarity)
+local nosmooth_rarity = 0.5
+local smooth_rarity_max = 0.6
+local smooth_rarity_min = 0.4
+local smooth_rarity_dif = smooth_rarity_max - smooth_rarity_min
+local perlin_scale = 500
 
 local contents_defined
 minetest.register_on_generated(function(minp, maxp, seed)
@@ -158,7 +145,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	local hm_zstride = divs+1
 
 	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
-	data = vm:get_data()
+	vm:get_data(data)
 	area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
 
 	for p_pos in area:iterp(minp, maxp) do	--remove tree stuff
@@ -344,7 +331,6 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	vm:set_lighting({day=0, night=0})
 	vm:calc_lighting()
 	vm:write_to_map()
-	data = nil
 	area = nil
 	riesenpilz.inform("data set", 2, t2)
 
diff --git a/settings.lua b/settings.lua
index de28902..b5b99af 100644
--- a/settings.lua
+++ b/settings.lua
@@ -1,6 +1,7 @@
 --This file contains configuration options for riesenpilz mod.
 
-riesenpilz.enable_mapgen = true
+-- mapgen size etc. does not work
+riesenpilz.enable_mapgen = false
 
 --Generate giant mushroom biomes everywhere
 riesenpilz.always_generate = false
@@ -8,15 +9,6 @@ riesenpilz.always_generate = false
 --Enables smooth transition of biomes.
 riesenpilz.smooth = true
 
---rarity in %
-riesenpilz.mapgen_rarity = 0.4
-
---size of the generated... (has an effect to the rarity, too)
-riesenpilz.mapgen_size = 200
-
---approximate size of smooth transitions
-riesenpilz.smooth_trans_size = 2
-
 --says some information.
 riesenpilz.info = true