diff --git a/locale/gen_combined/grilledham_map_gen/builders.lua b/locale/gen_combined/grilledham_map_gen/builders.lua
index c7f738d6..aae09c9a 100644
--- a/locale/gen_combined/grilledham_map_gen/builders.lua
+++ b/locale/gen_combined/grilledham_map_gen/builders.lua
@@ -67,11 +67,64 @@ function oval_builder(x_radius, y_radius)
     end
 end
 
-function picture_builder(data, width, height)
+local tile_map =
+{
+    [1] = false,
+    [2] = true,
+    [3] = "concrete",
+    [4] = "deepwater",
+    [5] = "deepwater-green",
+    [6] = "dirt",
+    [7] = "dirt-dark",
+    [8] = "grass",
+    [9] = "grass-dry",
+    [10] = "grass-medium",
+    [11] = "lab-dark-1",
+    [12] = "lab-dark-2",
+    [13] = "out-of-map",
+    [14] = "red-desert",
+    [15] = "red-desert-dark",
+    [16] = "sand",
+    [17] = "sand-dark",
+    [18] = "stone-path",
+    [19] = "water",
+    [20] = "water-green",
+}
+
+function decompress(pic)
+    local data = pic.data
+    local width = pic.width
+    local height = pic.height
+
+    local uncompressed = {}
+
+    for y = 1, height do
+        local row = data[y]
+        local u_row = {}
+        uncompressed[y] = u_row
+        local x = 1
+        for index = 1, #row, 2 do
+            local pixel = tile_map[row[index]]
+            local count = row[index + 1]
+
+            for i = 1, count do
+                u_row[x] = pixel
+                x = x + 1
+            end
+        end
+    end
+
+    return {width = width, height = height, data = uncompressed}
+end
+
+function picture_builder(pic)
+    local data = pic.data
+    local width = pic.width
+    local height = pic.height
+
     -- the plus one is because lua tables are one based.
     local half_width = math.floor(width / 2) + 1
     local half_height = math.floor(height / 2) + 1
-
     return function(x, y)
         x = math.floor(x)
         y = math.floor(y)
@@ -79,12 +132,7 @@ function picture_builder(data, width, height)
         local y2 = y + half_height
 
         if y2 > 0 and y2 <= height and x2 > 0 and x2 <= width  then
-           local pixel = "out-of-map"
-            if data[y2] ~= nil then
-               if data[y2][x2] ~= nil then
-                  pixel = data[y2][x2]
-               end
-            end
+            local pixel = data[y2][x2]
             return pixel
         else
             return false
@@ -171,6 +219,26 @@ function invert(builder)
     end
 end
 
+function throttle_x(builder, x_in, x_size)
+    return function(x, y, world_x, world_y)
+        if x % x_size < x_in then
+            return builder(x, y, world_x, world_y)
+        else
+            return false
+        end
+    end
+end
+
+function throttle_y(builder, y_in, y_size)
+    return function(x, y, world_x, world_y)
+        if y % y_size < y_in then
+            return builder(x, y, world_x, world_y)
+        else
+            return false
+        end
+    end
+end
+
 function throttle_xy(builder, x_in, x_size, y_in, y_size)
     return function(x, y, world_x, world_y)
         if x % x_size < x_in and y % y_size < y_in then
@@ -377,7 +445,7 @@ function change_map_gen_tile(builder, old_tile, new_tile)
     return function (local_x, local_y, world_x, world_y )
         local tile, entity = builder(local_x, local_y, world_x, world_y)
         if type(tile) == "boolean" and tile then
-            local gen_tile = MAP_GEN_SURFACE.get_tile(world_x, world_y)
+            local gen_tile = MAP_GEN_SURFACE.get_tile(world_x, world_y).name
             if old_tile == gen_tile then
                 tile = new_tile
             end
diff --git a/locale/gen_combined/grilledham_map_gen/data/biome_test.lua b/locale/gen_combined/grilledham_map_gen/data/biome_test.lua
index 27dd30bc..0c0fae65 100644
--- a/locale/gen_combined/grilledham_map_gen/data/biome_test.lua
+++ b/locale/gen_combined/grilledham_map_gen/data/biome_test.lua
@@ -1,24 +1,24 @@
 local tile_types = {
 	"concrete",
-"deepwater",
-"deepwater-green",
-"dirt",
-"dirt-dark",
-"grass",
-"grass-dry",
-"grass-medium",
-"hazard-concrete-left",
-"hazard-concrete-right",
-"lab-dark-1",
-"lab-dark-2",
-"red-desert",
-"red-desert-dark",
-"sand",
-"sand-dark",
-"stone-path",
-"water",
-"water-green",
-"out-of-map",
+	"deepwater",
+	"deepwater-green",
+	"dirt",
+	"dirt-dark",
+	"grass",
+	"grass-medium",
+	"grass-dry",
+	"hazard-concrete-left",
+	"hazard-concrete-right",
+	"lab-dark-1",
+	"lab-dark-2",
+	"red-desert",
+	"red-desert-dark",
+	"sand",
+	"sand-dark",
+	"stone-path",
+	"water",
+	"water-green",
+	"out-of-map",
 }
 local cols = 5
 local rows = 20 / cols
diff --git a/locale/gen_combined/grilledham_map_gen/map_gen.lua b/locale/gen_combined/grilledham_map_gen/map_gen.lua
index 84561827..147c79ce 100644
--- a/locale/gen_combined/grilledham_map_gen/map_gen.lua
+++ b/locale/gen_combined/grilledham_map_gen/map_gen.lua
@@ -1,4 +1,89 @@
 require("locale.gen_combined.grilledham_map_gen.builders")
+local Thread = require "locale.utils.Thread"
+
+
+function run_init(params)
+   global._tiles_hold = {}
+   global._decoratives_hold = {}
+   global._entities_hold = {}
+end
+
+function run_place_tiles(params)
+	local surface = params.surface
+   surface.set_tiles(global._tiles_hold)
+end
+
+function run_place_items(params)
+	local surface = params.surface
+   for _,deco in pairs(global._decoratives_hold) do
+     surface.create_decoratives{check_collision=false, decoratives={deco}}
+   end
+   for _,deco in pairs(global._decoratives_hold) do
+     surface.create_decoratives{check_collision=false, decoratives={deco}}
+   end
+   for _, entity in ipairs(global._entities_hold) do
+      if surface.can_place_entity {name=entity.name, position=entity.position} then
+         surface.create_entity {name=entity.name, position=entity.position}
+      end
+   end
+end
+
+function run_calc_items(params)
+   local top_x = params.top_x
+   local top_y = params.top_y
+
+   for y = top_y, top_y + 31 do
+      for x = top_x, top_x + 31 do
+
+         -- local coords need to be 'centered' to allow for correct rotation and scaling.
+         local tile, entity = MAP_GEN(x + 0.5, y + 0.5, x, y)
+
+         if type(tile) == "boolean" and not tile then
+            table.insert( global._tiles_hold, {name = "out-of-map", position = {x, y}} )
+         elseif type(tile) == "string" then
+            table.insert( global._tiles_hold, {name = tile, position = {x, y}} )
+
+            if tile == "water" or tile == "deepwater" or tile == "water-green" or  tile == "deepwater-green" then
+              local a = x + 1
+              table.insert(global._tiles_hold, {name = tile, position = {a,y}})
+              local a = y + 1
+              table.insert(global._tiles_hold, {name = tile, position = {x,a}})
+              local a = x - 1
+              table.insert(global._tiles_hold, {name = tile, position = {a,y}})
+              local a = y - 1
+              table.insert(global._tiles_hold, {name = tile, position = {x,a}})
+            end
+
+            if map_gen_decoratives then
+               tile_decoratives = check_decorative(tile, x, y)
+               for _,tbl in ipairs(tile_decoratives) do
+                  table.insert(global._decoratives_hold, tbl)
+               end
+
+
+               tile_entities = check_entities(tile, x, y)
+               for _,entity in ipairs(tile_entities) do
+                  table.insert(global._entities_hold, entity)
+               end
+            end
+         end
+
+         if entity then
+            table.insert(global._entities_hold, entity)
+         end
+
+      end
+   end
+end
+
+function run_chart_update(params)
+	local x = params.area.left_top.x / 32
+	local y = params.area.left_top.y / 32
+	if game.forces.player.is_chunk_charted(params.surface, {x,y} ) then
+		-- Don't use full area, otherwise adjacent chunks get charted
+		game.forces.player.chart(params.surface, {{  params.area.left_top.x,  params.area.left_top.y}, { params.area.left_top.x+30,  params.area.left_top.y+30} } )
+	end
+end
 
 function run_combined_module(event)
 
@@ -10,70 +95,30 @@ function run_combined_module(event)
    local area = event.area
    local surface = event.surface
    MAP_GEN_SURFACE = surface
-   local tiles = {}
-   local entities = {}
-   local decoratives = {}
+
 
    local top_x = area.left_top.x
    local top_y = area.left_top.y
 
    if map_gen_decoratives then
-      for _, e in pairs(surface.find_entities_filtered{area=area, type="simple-entity"}) do
+      for _, e in pairs(surface.find_entities_filtered{area=area, type="decorative"}) do
    		e.destroy()
       end
       for _, e in pairs(surface.find_entities_filtered{area=area, type="tree"}) do
    		e.destroy()
       end
-   end
-
-
-   for y = top_y, top_y + 31 do
-      for x = top_x, top_x + 31 do
-
-         -- local coords need to be 'centered' to allow for correct rotation and scaling.
-         local tile, entity = MAP_GEN(x + 0.5, y + 0.5, x, y)
-
-         if type(tile) == "boolean" and not tile then
-            table.insert( tiles, {name = "out-of-map", position = {x, y}} )
-         elseif type(tile) == "string" then
-            table.insert( tiles, {name = tile, position = {x, y}} )
-
-            if map_gen_decoratives then
-               tile_decoratives = check_decorative(tile, x, y)
-               for _,tbl in ipairs(tile_decoratives) do
-                  table.insert(decoratives, tbl)
-               end
-
-
-               tile_entities = check_entities(tile, x, y)
-               for _,entity in ipairs(tile_entities) do
-                  table.insert(entities, entity)
-               end
-            end
-         end
-
-         if entity then
-            table.insert(entities, entity)
-         end
-
+      for _, e in pairs(surface.find_entities_filtered{area=area, type="simple-entity"}) do
+   		e.destroy()
       end
    end
 
-   -- set tiles.
-   surface.set_tiles(tiles, false)
+   Thread.queue_action("run_init", {} )
 
-   -- set entities
-   for _, entity in ipairs(entities) do
-      if surface.can_place_entity {name=entity.name, position=entity.position} then
-         surface.create_entity {name=entity.name, position=entity.position}
-      end
-   end
+   Thread.queue_action("run_calc_items", {surface = event.surface, top_x = top_x, top_y = top_y})
 
-	for _,deco in pairs(decoratives) do
-      if deco ~= nil then
-		    surface.create_decoratives({check_collision=true, decoratives={deco}})
-      end
-	end
+   Thread.queue_action("run_place_tiles", {surface = event.surface})
+   Thread.queue_action("run_place_items", {surface = event.surface})
+   Thread.queue_action("run_chart_update", {area = event.area, surface = event.surface} )
 
 end
 
@@ -92,15 +137,46 @@ local decorative_options = {
       {"green-asterisk", 25},
       {"green-bush-mini", 7},
    },
-   ["grass-dry"] = {},
-   ["grass-medium"] = {},
+   ["grass-medium"] = {
+      {"green-carpet-grass", 12},
+      {"green-hairy-grass", 28},
+      {"green-bush-mini", 40},
+      {"green-pita", 24},
+      {"green-small-grass", 48},
+      {"green-asterisk", 100},
+      {"green-bush-mini", 28},
+   },
+   ["grass-dry"] = {
+      {"green-carpet-grass", 24},
+      {"green-hairy-grass", 56},
+      {"green-bush-mini", 80},
+      {"green-pita", 48},
+      {"green-small-grass", 96},
+      {"green-asterisk", 200},
+      {"green-bush-mini", 56},
+   },
    ["hazard-concrete-left"] = {},
    ["hazard-concrete-right"] = {},
    ["lab-dark-1"] = {},
    ["lab-dark-2"] = {},
-   ["red-desert"] = {},
-   ["red-desert-dark"] = {},
-   ["sand"] = {},
+   ["red-desert"] = {
+      {"brown-carpet-grass", 35},
+      {"orange-coral-mini", 45},
+      {"red-asterisk", 45},
+      {"red-desert-bush", 12},
+      {"red-desert-rock-medium", 375},
+      {"red-desert-rock-small", 200},
+      {"red-desert-rock-tiny", 30},
+   },
+   ["red-desert-dark"] = {
+      {"brown-carpet-grass", 70},
+      {"orange-coral-mini", 90},
+      {"red-asterisk", 90},
+      {"red-desert-bush", 35},
+      {"red-desert-rock-medium", 375},
+      {"red-desert-rock-small", 200},
+      {"red-desert-rock-tiny", 150},
+   },
    ["sand-dark"] = {},
    ["stone-path"] = {},
    ["water"] = {},
@@ -143,8 +219,30 @@ local entity_options = {
    ["hazard-concrete-right"] = {},
    ["lab-dark-1"] = {},
    ["lab-dark-2"] = {},
-   ["red-desert"] = {},
-   ["red-desert-dark"] = {},
+   ["red-desert"] = {
+      {"dry-tree", 400},
+      {"dry-hairy-tree", 400},
+      {"tree-06", 500},
+      {"tree-06", 500},
+      {"tree-01", 500},
+      {"tree-02", 500},
+      {"tree-03", 500},
+      {"red-desert-rock-big-01", 200},
+      {"red-desert-rock-huge-01", 400},
+      {"red-desert-rock-huge-02", 400},
+   },
+   ["red-desert-dark"] = {
+      {"dry-tree", 400},
+      {"dry-hairy-tree", 400},
+      {"tree-06", 500},
+      {"tree-06", 500},
+      {"tree-01", 500},
+      {"tree-02", 500},
+      {"tree-03", 500},
+      {"red-desert-rock-big-01", 200},
+      {"red-desert-rock-huge-01", 400},
+      {"red-desert-rock-huge-02", 400},
+   },
    ["sand"] = {},
    ["sand-dark"] = {},
    ["stone-path"] = {},
diff --git a/locale/gen_combined/grilledham_map_gen/presets/GoT.lua b/locale/gen_combined/grilledham_map_gen/presets/GoT.lua
index c99bfb06..595b73a8 100644
--- a/locale/gen_combined/grilledham_map_gen/presets/GoT.lua
+++ b/locale/gen_combined/grilledham_map_gen/presets/GoT.lua
@@ -1,6 +1,6 @@
 require "locale.gen_combined.grilledham_map_gen.map_gen"
 require "locale.gen_combined.grilledham_map_gen.builders"
-
+map_gen_decoratives = true
 local pic = require "locale.gen_combined.grilledham_map_gen.data.GoT"
 local pic = decompress(pic)
 
diff --git a/locale/gen_combined/grilledham_map_gen/presets/biome_test.lua b/locale/gen_combined/grilledham_map_gen/presets/biome_test.lua
index 3cbd24db..ef371e8e 100644
--- a/locale/gen_combined/grilledham_map_gen/presets/biome_test.lua
+++ b/locale/gen_combined/grilledham_map_gen/presets/biome_test.lua
@@ -4,7 +4,7 @@ map_gen_decoratives = true
 
 local pic = require "locale.gen_combined.grilledham_map_gen.data.biome_test"
 
-local shape = picture_builder(pic.data, pic.width, pic.height)
+local shape = picture_builder(pic)
 
 --shape = change_tile(shape, false, "out-of-map")
 
diff --git a/map_layout.lua b/map_layout.lua
index be6fe40d..c2be0337 100644
--- a/map_layout.lua
+++ b/map_layout.lua
@@ -24,6 +24,7 @@ in this file and your run_*type*_module(event) function will be called.
 --MAP_GEN = require "locale.gen_combined.grilledham_map_gen.presets.maori"
 --MAP_GEN = require "locale.gen_combined.grilledham_map_gen.presets.goat"
 MAP_GEN = require "locale.gen_combined.grilledham_map_gen.presets.biome_test"
+--MAP_GEN = require "locale.gen_combined.grilledham_map_gen.presets.GoT"
 
 --shapes--
 --require "locale.gen_shape.left"