diff --git a/minecraft/gen/mc.py b/minecraft/gen/mc.py
index 0225e32..b77c26d 100644
--- a/minecraft/gen/mc.py
+++ b/minecraft/gen/mc.py
@@ -3,6 +3,7 @@ import struct
 from pprint import pprint
 from itertools import chain
 from collections import defaultdict
+import functools
 
 import mcregion
 import vec3
@@ -22,52 +23,52 @@ non_solid_blocks = {
     data.BlockID.TALL_GRASS,
     data.BlockID.MUSHROOM_1,
     data.BlockID.MUSHROOM_2,
+    data.BlockID.FLOWER,
+    data.BlockID.ROSE,
+    data.BlockID.SAPLING,
 }
 
+def neighbor_exists(level_table, chunk_x, chunk_z, nx, ny, nz):
+    if ny > 127 or ny < 0:
+        return False
+    nx, n_chunk_x = wrap_n(nx, chunk_x)
+    nz, n_chunk_z = wrap_n(nz, chunk_z)
+    assert nx <= 15 and nx >= 0
+    assert nz <= 15 and nz >= 0
+    key = (n_chunk_x, n_chunk_z)
+    if key not in level_table:
+        return True
+    n_block_index = mcregion.block_index_from_xyz(nx, ny, nz)
+    n_block_id = level_table[key].blocks[n_block_index]
+
+    has_neighbor = (n_block_id != data.BlockID.AIR) and (n_block_id not in non_solid_blocks)
+    return has_neighbor
+
 def block_neighbors(level_table, chunk_x, chunk_z, block_index):
     block_id = level_table[(chunk_x, chunk_z)].blocks[block_index]
     if block_id == data.BlockID.AIR:
         return
 
-    def neighbor_exists(nx, ny, nz):
-        if ny > 127 or ny < 0:
-            return False
-        nx, n_chunk_x = wrap_n(nx, chunk_x)
-        nz, n_chunk_z = wrap_n(nz, chunk_z)
-        if nx > 15 or nx < 0:
-            return True
-        if nz > 15 or nz < 0:
-            return True
-        n_block_index = mcregion.block_index_from_xyz(nx, ny, nz)
-        key = (n_chunk_x, n_chunk_z)
-        if key not in level_table:
-            return True
-        n_block_id = level_table[key].blocks[n_block_index]
+    xyz = mcregion.xyz_from_block_index(block_index)
 
-        has_neighbor = (n_block_id != data.BlockID.AIR) and (n_block_id not in non_solid_blocks)
-        return has_neighbor
-
-    x, y, z = mcregion.xyz_from_block_index(block_index)
-
-    center_position = vec3.add((x, y, z), (chunk_x * 16, 0, chunk_z * 16))
+    center_position = vec3.add(xyz, (chunk_x * 16, 0, chunk_z * 16))
 
     def find_non_neighbors():
         for i, normal in enumerate(vertex_buffer.normals):
-            neighbor = vec3.add(normal, (x, y, z))
-            if not neighbor_exists(*neighbor):
+            neighbor = vec3.add(normal, xyz)
+            if not neighbor_exists(level_table, chunk_x, chunk_z, *neighbor):
                 yield i
 
     normal_indices = list(find_non_neighbors())
     if block_id in non_solid_blocks or normal_indices:
         yield center_position, block_id, normal_indices
 
-def devoxelize_region(level_table):
-    for chunk_x, chunk_z in level_table.keys():
+def devoxelize_region(level_table, level_table_keys):
+    for chunk_x, chunk_z in level_table_keys:
         for block_index in range(128 * 16 * 16):
             yield from block_neighbors(level_table, chunk_x, chunk_z, block_index)
 
-def build_level_table(mem, locations):
-    level_table = {}
+def build_level_table(level_table, mem, locations):
     for location in locations:
         try:
             level = mcregion.parse_location(mem, location)
@@ -93,6 +94,11 @@ def build_block_configuration_table():
 
 non_cube_blocks = {
     data.BlockID.TALL_GRASS,
+    data.BlockID.MUSHROOM_1,
+    data.BlockID.MUSHROOM_2,
+    data.BlockID.FLOWER,
+    data.BlockID.ROSE,
+    data.BlockID.SAPLING,
 }
 
 def pack_instance_data(position, block_id):
@@ -148,11 +154,11 @@ def build_block_instances(blocks):
 
     with open(f"{data_path}.instance.cfg", "wb") as f:
         for instance_count, offset in configuration_instance_count_offset:
-            print(instance_count, offset)
+            #print(instance_count, offset)
             f.write(struct.pack("<ii", instance_count, offset))
 
-def main(mcr_path, data_path):
-    with open(mcr_path, "rb") as f:
+def level_table_from_path(level_table, path):
+    with open(path, "rb") as f:
         buf = f.read()
     mem = memoryview(buf)
 
@@ -161,13 +167,34 @@ def main(mcr_path, data_path):
     offset, timestamps = mcregion.parse_timestamps(mem, offset)
     assert offset == 0x2000
 
-    level_table = build_level_table(mem, locations)
-    blocks = devoxelize_region(level_table)
+    build_level_table(level_table, mem, locations)
+
+all_paths = [
+    "/home/bilbo/Love2DWorld/region/r.0.0.mcr",
+    "/home/bilbo/Love2DWorld/region/r.-1.-1.mcr",
+    "/home/bilbo/Love2DWorld/region/r.0.-1.mcr",
+    "/home/bilbo/Love2DWorld/region/r.-1.0.mcr",
+]
+
+def main2(level_table, level_table_keys):
+    blocks = devoxelize_region(level_table, level_table_keys)
     build_block_instances(blocks)
 
-    #pprint(list(build_block_configuration_table()))
+def main(mcr_path, data_path):
+    assert mcr_path in all_paths
+    level_table = {}
+    level_table_from_path(level_table, mcr_path)
+    level_table_keys = list(level_table.keys())
+    for path in all_paths:
+        if path == mcr_path:
+            continue
+        level_table_from_path(level_table, path)
+
+    main2(level_table, level_table_keys)
+    #import cProfile
+    #cProfile.runctx("main2(level_table, level_table_keys)", {},
+    #                {"level_table_keys": level_table_keys, "level_table": level_table, "main2": main2})
 
 mcr_path = sys.argv[1]
 data_path = sys.argv[2]
-
 main(mcr_path, data_path)
diff --git a/minecraft/gen/mc.sh b/minecraft/gen/mc.sh
new file mode 100644
index 0000000..3ab7461
--- /dev/null
+++ b/minecraft/gen/mc.sh
@@ -0,0 +1,6 @@
+set -eux
+cd ./minecraft/gen
+python mc.py ~/Love2DWorld/region/r.0.0.mcr ../region.0.0 &
+python mc.py ~/Love2DWorld/region/r.-1.-1.mcr ../region.-1.-1 &
+python mc.py ~/Love2DWorld/region/r.0.-1.mcr ../region.0.-1 &
+python mc.py ~/Love2DWorld/region/r.-1.0.mcr ../region.-1.0 &
diff --git a/minecraft/gen/mcregion.py b/minecraft/gen/mcregion.py
index 8c5337d..6ea0382 100644
--- a/minecraft/gen/mcregion.py
+++ b/minecraft/gen/mcregion.py
@@ -217,15 +217,30 @@ def parse_location(mem, location):
     level = level_from_tag(tag)
     return level
 
-def xyz_from_block_index(block_index):
+def _xyz_from_block_index(block_index):
     assert block_index >= 0 and block_index < (128 * 16 * 16)
-    x = int(block_index / (128 * 16))
-    y = int(block_index % 128)
-    z = int(int(block_index / 128) % 16)
+    x = block_index // (128 * 16)
+    y = block_index % 128
+    z = (block_index // 128) % 16
     return x, y, z
 
-def block_index_from_xyz(x, y, z):
+def _block_index_from_xyz(x, y, z):
     assert x >= 0 and x < 16
     assert y >= 0 and y < 128
     assert z >= 0 and z < 16
     return int(y + z * 128 + x * 128 * 16)
+
+xyz_to_block_index = {}
+block_index_to_xyz = {}
+
+for i in range(128 * 16 * 16):
+    xyz = _xyz_from_block_index(i)
+    assert _block_index_from_xyz(*xyz) == i
+    xyz_to_block_index[xyz] = i
+    block_index_to_xyz[i] = xyz
+
+def xyz_from_block_index(block_index):
+    return block_index_to_xyz[block_index]
+
+def block_index_from_xyz(x, y, z):
+    return xyz_to_block_index[(x, y, z)]
diff --git a/minecraft/gen/tallgrass.obj b/minecraft/gen/tallgrass.obj
index 3f84163..32a4995 100644
--- a/minecraft/gen/tallgrass.obj
+++ b/minecraft/gen/tallgrass.obj
@@ -1,14 +1,14 @@
 # Blender 5.0.0
 # www.blender.org
 o TallGrass
-v 0.800011 0.600021 0.800011
-v 0.800011 -1.000000 0.800011
-v -0.800010 -1.000000 0.800011
-v -0.800011 0.600021 0.800011
-v -0.800011 0.600021 -0.800011
-v -0.800011 -1.000000 -0.800011
-v 0.800011 -1.000000 -0.800011
-v 0.800010 0.600022 -0.800011
+v 0.800000 0.600000 0.800000
+v 0.800000 -1.000000 0.800000
+v -0.800000 -1.000000 0.800000
+v -0.800000 0.600000 0.800000
+v -0.800000 0.600000 -0.800000
+v -0.800000 -1.000000 -0.800000
+v 0.800000 -1.000000 -0.800000
+v 0.800000 0.600000 -0.800000
 vn 0.7071 -0.0000 0.7071
 vn 0.7071 -0.0000 -0.7071
 vt 1.000000 1.000000
diff --git a/minecraft/region.-1.-1.instance.cfg b/minecraft/region.-1.-1.instance.cfg
index c925ab2..31a6a33 100644
Binary files a/minecraft/region.-1.-1.instance.cfg and b/minecraft/region.-1.-1.instance.cfg differ
diff --git a/minecraft/region.-1.-1.instance.vtx b/minecraft/region.-1.-1.instance.vtx
index eb04261..a8a1902 100644
Binary files a/minecraft/region.-1.-1.instance.vtx and b/minecraft/region.-1.-1.instance.vtx differ
diff --git a/minecraft/region.-1.0.instance.cfg b/minecraft/region.-1.0.instance.cfg
index bec1c85..a50501e 100644
Binary files a/minecraft/region.-1.0.instance.cfg and b/minecraft/region.-1.0.instance.cfg differ
diff --git a/minecraft/region.-1.0.instance.vtx b/minecraft/region.-1.0.instance.vtx
index df8f91d..c678e57 100644
Binary files a/minecraft/region.-1.0.instance.vtx and b/minecraft/region.-1.0.instance.vtx differ
diff --git a/minecraft/region.0.-1.instance.cfg b/minecraft/region.0.-1.instance.cfg
index 599397e..f74e23d 100644
Binary files a/minecraft/region.0.-1.instance.cfg and b/minecraft/region.0.-1.instance.cfg differ
diff --git a/minecraft/region.0.-1.instance.vtx b/minecraft/region.0.-1.instance.vtx
index 33e417b..6db8213 100644
Binary files a/minecraft/region.0.-1.instance.vtx and b/minecraft/region.0.-1.instance.vtx differ
diff --git a/minecraft/region.0.0.instance.cfg b/minecraft/region.0.0.instance.cfg
index c82cbea..150cbfd 100644
Binary files a/minecraft/region.0.0.instance.cfg and b/minecraft/region.0.0.instance.cfg differ
diff --git a/minecraft/region.0.0.instance.vtx b/minecraft/region.0.0.instance.vtx
index 319c4df..d6c02eb 100644
Binary files a/minecraft/region.0.0.instance.vtx and b/minecraft/region.0.0.instance.vtx differ
diff --git a/shader/test.frag b/shader/test.frag
index 11dce84..b6c5264 100644
--- a/shader/test.frag
+++ b/shader/test.frag
@@ -51,7 +51,7 @@ void main()
 
   if (diffuse_intensity < 0.1)
     diffuse_intensity = 0.1;
-  if (fs_in.BlockID == 31) // tall_grass
+  if (fs_in.BlockID == 31 || fs_in.BlockID == 39 || fs_in.BlockID == 40 || fs_in.BlockID == 37 || fs_in.BlockID == 38 || fs_in.BlockID == 6) // tall_grass
     diffuse_intensity = 1.0;
 
   FragColor = vec4(texture_color.xyz * vec3(diffuse_intensity), 1.0);