diff --git a/Node2D.tscn b/Node2D.tscn
index dabab40..3afd3ec 100644
--- a/Node2D.tscn
+++ b/Node2D.tscn
@@ -1,8 +1,9 @@
-[gd_scene load_steps=4 format=2]
+[gd_scene load_steps=5 format=2]
 
 [ext_resource path="res://palette_mat.tres" type="Material" id=1]
 [ext_resource path="res://Node2D.gd" type="Script" id=2]
 [ext_resource path="res://test/audio_system.tscn" type="PackedScene" id=3]
+[ext_resource path="res://test/worldmap_system.tscn" type="PackedScene" id=4]
 
 [node name="Control" type="Control"]
 anchor_right = 1.0
@@ -27,4 +28,6 @@ selected = 0
 [node name="audio_system" parent="." instance=ExtResource( 3 )]
 position = Vector2( 0, 400 )
 
+[node name="worldmap_system" parent="." instance=ExtResource( 4 )]
+
 [connection signal="item_selected" from="Node2D/OptionButton" to="Node2D" method="_on_OptionButton_item_selected"]
diff --git a/scripts/loaders/map_loader.gd b/scripts/loaders/map_loader.gd
index a0627f0..910d343 100644
--- a/scripts/loaders/map_loader.gd
+++ b/scripts/loaders/map_loader.gd
@@ -76,21 +76,20 @@ class WorldMap:
 	func get_block_pathing_flags(id: int) -> int:
 		return block_pathing[id]
 
-	func make_tile_atlas() -> Image:
+	func make_tile_map() -> Image:
 		var image := Image.new()
 		var data := PoolByteArray()
 		data.resize(tile_width*tile_height)
-		var block_tile := 0
-		for y_off in range(0, tile_height*tile_width, tile_width):
+		var block_idx := 0
+		for y_off in range(0, tile_height*tile_width, tile_width*2):
 			for x_off in range(0, tile_width, 2):
-				data[y_off + x_off] = self.block_tile_ids[block_tile]
-				block_tile += 1
-				data[y_off + x_off + 1] = self.block_tile_ids[block_tile]
-				block_tile += 1
-				data[y_off + tile_width + x_off] = self.block_tile_ids[block_tile]
-				block_tile += 1
-				data[y_off + tile_width + x_off + 1] = self.block_tile_ids[block_tile]
-				block_tile += 1
+				var tile_offset = self.blockmap[block_idx] * 4
+				block_idx += 1
+				data[y_off + x_off] = self.block_tile_ids[tile_offset]
+				data[y_off + x_off + 1] = self.block_tile_ids[tile_offset+1]
+				data[y_off + tile_width + x_off] = self.block_tile_ids[tile_offset+2]
+				data[y_off + tile_width + x_off + 1] = self.block_tile_ids[tile_offset+3]
+		image.create_from_data(tile_width, tile_height, false, Image.FORMAT_R8, data)
 		return image
 
 var worldmaps = [WorldMap.new(), WorldMap.new(), WorldMap.new(), WorldMap.new(), WorldMap.new()]
@@ -131,22 +130,26 @@ func load_worldmaps(rom: File):
 		# Repeated blocks along a row are run-length-encoded (RLE)
 		# Certain blocks (mountains) expand to 1x3
 		var blockmap = PoolByteArray()
-		blockmap.resize(WorldMap.block_height * WorldMap.block_width)
+		# blockmap.resize(WorldMap.block_height * WorldMap.block_width)  # Try this later if performance is a problem
 		for chunk_id in range(worldmap_id*0x100, (worldmap_id+1)*0x100):
 			rom.seek(chunk_addresses[chunk_id])
-			while blockmap.size() < 256:
+			var chunk_size := 0
+			while chunk_size < 256:
 				var b := rom.get_8()
 				if b >= 0xC0:  # RLE
 					var count := b-0xBF
 					var block = rom.get_8()
 					for i in count:
 						blockmap.append(block)
+					chunk_size += count
 				else:
 					blockmap.append(b)
+					chunk_size += 1
 					if b == 0x0C or b == 0x1C or b == 0x2C:
 						# Mountain blocks expand to a 1x3
 						blockmap.append(b+1)
 						blockmap.append(b+2)
+						chunk_size += 2
 		worldmaps[worldmap_id].blockmap = blockmap
 
 func update_worldmap_block_tile_ids(worldmap_block_tile_ids: Array):
diff --git a/scripts/loaders/sprite_loader.gd b/scripts/loaders/sprite_loader.gd
index f058952..64f0d21 100644
--- a/scripts/loaders/sprite_loader.gd
+++ b/scripts/loaders/sprite_loader.gd
@@ -198,11 +198,11 @@ func snes_get_tile(rom: File, offset: int, length: int) -> Image:
 func make_tile_atlas(tile_images) -> Image:
 	var r := Rect2(0, 0, 8, 8)
 	var image = Image.new()
-	image.create(256, 256, false, Image.FORMAT_R8)
+	image.create(128, 128, false, Image.FORMAT_R8)
 	var tile = 0
 	for y in tile_images.size()/16:
 		for x in 16:
-			image.blit_rect(tile_images[tile], r, Vector2(x, y)*8)
+			image.blit_rect(tile_images[tile], r, Vector2(x*8, y*8))
 			tile += 1
 	return image
 
diff --git a/shaders/worldmap_shader.gdshader b/shaders/worldmap_shader.gdshader
index b9eaa59..7e34eaf 100644
--- a/shaders/worldmap_shader.gdshader
+++ b/shaders/worldmap_shader.gdshader
@@ -1,8 +1,8 @@
 shader_type canvas_item;
-uniform sampler2D tiles;
-uniform sampler2D palette;
+uniform sampler2D tile_atlas : hint_normal;
+uniform sampler2D palette : hint_normal;
 // uniform float tile_width = 8.0;
-uniform float tilemap_width = 256.0;  // Require square tilemap for now
+uniform float tilemap_width = 512.0;  // Require square tilemap for now
 const float index_scale = 255.0 / 16.0;
 
 
@@ -10,19 +10,38 @@ const float index_scale = 255.0 / 16.0;
 // tiles hardcoded to 16x16 tiles for now
 // palette hardcoded to 16x16 colors for now
 
-void fragment() {
-	// GLES2
-	float tile_idx = texture(TEXTURE, UV).a * index_scale;
-	vec2 tile_uv = vec2(fract(tile_idx), trunc(tile_idx) / 16.0);
-	vec2 sub_tile_uv = fract(UV / tilemap_width);
+vec2 get_tile_atlas_uv(float tile_id, vec2 uv) {
+	float tile_idx16 = tile_id * index_scale;  // Rescale from [0.0, 1.0] to [0, 255] to [0, 15.9375 (15+15/16)]
+	float tile_row = trunc(tile_idx16) / 16.0;
+	float tile_col = fract(tile_idx16);
+	vec2 tile_uv = vec2(tile_col, tile_row);  // Convert 15.9375 to vec2(0.9375==15/16, (15)/16), this should result in integer coordinates in [0,15] scaled to [0,15/16] for UV
+	vec2 sub_tile_uv = fract(uv * tilemap_width);
 
 	// TODO: add sea HScroll, waterfall VScroll tile UV modulation
+	return tile_uv + (sub_tile_uv/16.0);
+}
+
+void fragment() {
+	// GLES2
+	float s = texture(TEXTURE, UV).a;
+	// float tile_idx = texture(TEXTURE, UV).a * index_scale;  // Rescale from [0.0, 1.0] to [0, 255] to [0, 15.9375 (15+15/16)]
+	// float tile_row = trunc(tile_idx) / 16.0;
+	// float tile_col = fract(tile_idx);
+	// vec2 tile_uv = vec2(tile_col, tile_row);  // Convert 15.9375 to vec2(0.9375==15/16, (15)/16), this should result in integer coordinates in [0,15] scaled to [0,15/16] for UV
+	// vec2 sub_tile_uv = vec2(0.5, 0.5);  //fract(UV * tilemap_width);
+
 	// TODO: move cycling palette to a sampler2DArray or sampler3D rather than rebinding
 
-	float color_idx = texture(tiles, tile_uv + (sub_tile_uv/16.0)).a * index_scale;
-	float palette_uv = vec2(fract(color_idx), trunc(color_idx) / 16.0);
+	vec2 lut_uv = get_tile_atlas_uv(s, UV);
+	// vec2 lut_uv = tile_uv;
+	float color_id = texture(tile_atlas, lut_uv).a;
+	float color_idx16 = color_id * index_scale;
+	float pal_row = trunc(color_idx16) / 16.0;
+	float pal_col = fract(color_idx16);
+	vec2 palette_uv = vec2(pal_col, pal_row);
 	COLOR = texture(palette, palette_uv);
 
-	if (color_idx == 0.0)
-		COLOR.a = 0.0;
+	// if (color_idx16 == 0.0)
+	// 	COLOR.a = 0.0;
+	COLOR.a = 1.0;
 }
diff --git a/test/worldmap_system.gd b/test/worldmap_system.gd
new file mode 100644
index 0000000..8444260
--- /dev/null
+++ b/test/worldmap_system.gd
@@ -0,0 +1,61 @@
+extends Node2D
+
+var pal_shader_mat := preload('res://palette_mat.tres')
+var worldmap_shader_mat := preload('res://worldmap_palette_mat.tres')
+
+var map_images := []
+var map_textures := []
+var map_texrects := []
+
+func _create_palette_and_atlas_texrects() -> void:
+	for tileset in 3:
+		# Debug the Atlases
+		var texrect = TextureRect.new()
+		texrect.rect_position.x = tileset * 256 * 2
+		texrect.rect_scale *= 16
+		texrect.texture = SpriteLoader.worldmap_palette_textures[tileset]
+		map_texrects.append(texrect)
+		add_child(texrect)
+		texrect = TextureRect.new()
+		texrect.rect_position.x = tileset * 256 * 2
+		texrect.rect_position.y = 256
+		texrect.rect_scale *= 4
+		texrect.texture = SpriteLoader.worldmap_tile_atlas_textures[tileset]
+		texrect.material = pal_shader_mat.duplicate()
+		texrect.material.set_shader_param('palette', SpriteLoader.worldmap_palette_textures[tileset])
+		map_texrects.append(texrect)
+		add_child(texrect)
+		texrect = TextureRect.new()
+		texrect.rect_position.x = tileset * 256 * 2
+		texrect.rect_position.y = 768
+		texrect.rect_scale *= 4
+		texrect.texture = SpriteLoader.worldmap_tile_atlas_textures[tileset]
+		map_texrects.append(texrect)
+		add_child(texrect)
+
+func _create_worldmap_texrects() -> void:
+	var map_tilesets = [0, 1, 0, 2, 2]
+	for i in 1:
+		var tileset = map_tilesets[i]
+		var image = MapLoader.worldmaps[i].make_tile_map()
+		map_images.append(image)
+		var tex := SpriteLoader.texture_from_image(image)
+		map_textures.append(tex)
+		var texrect = TextureRect.new()
+		texrect.rect_scale *= 8  #8  # Needs to have at least 1 pixel per tile pixel
+		texrect.texture = tex
+		texrect.material = worldmap_shader_mat.duplicate()
+		texrect.material.set_shader_param('palette', SpriteLoader.worldmap_palette_textures[tileset])
+		texrect.material.set_shader_param('tile_atlas', SpriteLoader.worldmap_tile_atlas_textures[tileset])
+		map_texrects.append(texrect)
+		add_child(texrect)
+
+# Called when the node enters the scene tree for the first time.
+func _ready() -> void:
+	# Only create this after MapLoader and SpriteLoader have loaded!
+	_create_worldmap_texrects()
+
+
+# Called every frame. 'delta' is the elapsed time since the previous frame.
+#func _process(delta: float) -> void:
+#	pass
diff --git a/test/worldmap_system.tscn b/test/worldmap_system.tscn
new file mode 100644
index 0000000..05b7f2d
--- /dev/null
+++ b/test/worldmap_system.tscn
@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://test/worldmap_system.gd" type="Script" id=1]
+
+[node name="worldmap_system" type="Node2D"]
+script = ExtResource( 1 )
diff --git a/worldmap_palette_mat.tres b/worldmap_palette_mat.tres
new file mode 100644
index 0000000..2beb8e9
--- /dev/null
+++ b/worldmap_palette_mat.tres
@@ -0,0 +1,7 @@
+[gd_resource type="ShaderMaterial" load_steps=2 format=2]
+
+[ext_resource path="res://shaders/worldmap_shader.gdshader" type="Shader" id=1]
+
+[resource]
+shader = ExtResource( 1 )
+shader_param/tilemap_width = 256.0