Implement extended world heights from Y-64 to Y319 #3473 (#3473)

* Begin to implement extended world heights:
 - Implemented in Bukkit module (and where required in Core module)

* Implement extended world heights into core module

* Add min gen height to setup,

* Default gen/build heights based on minecraft version

* Few fixes

* Fix up queues

* Address comments

* Make road schematic stuff slightly more efficient by sharing queues

* Minor fixes, don't overlay error many times for the same y

* Fix incorrect schematic paste height, undo changes to HybridUtils

* Overhall regenallroads method to make it work, make sure BukkitChunkCoordinator can/will finish

* Process chunks in order when regenerating all roads

* Address comments

* Address comments

* Ground level//bedrock is at min gen height
 - Add comment on == rather than <= being used
 - It's because it's only checking for the bedrock layer being broken if that's disabled

* Fix offset for min build height in SchematicHandler

* Better javadoc

Co-authored-by: Hannes Greule <SirYwell@users.noreply.github.com>

* Address inclusivity issues for max world height

* Javadocs/comments/deprecation

* Use world min/max heights if present in QueueCoordinator

* Address some deprecations for regions and biome setting

* Add a count for chunks we're currently trying to load to not skip chunks at the end of a queue's edit

* Use minGenHeight + 1 rather than build height in AugmentedUtils

* Create utility method for layer index in GenChunk

* Correct height in HybridUtils, also use minGenHeight + 1

* Don't magically split to 128 height in regeneration

* Add utility methods for world height in QueueCoordinator

* Clean up ClassicPlotManager road creation/removal

* Start generation at min gen height if bedrock is disabled

* min gen height is set in PlotArea

* Add note on schem y normalisation

* Improve plot getVolume method readability

* Don't overly extend height when regenerating road region

* y index utility method in ChunknQueueCoordinator

* Layer index utility method in LocalChunk

* Use version min/max heights if world not present in QueueCoordinator

* Fix min -> max

* Don't allow players to modify outside build height when using plot set  / schematics.
 - Also fixes schematic height issues

* Remove debug

* Address comments

* Switch loadingChunks to AtomicInteger to be safe (in case of multi-threaded)

* Fix "security" issue that was already present

* Ensure sign isn't physicsed

Co-authored-by: Hannes Greule <SirYwell@users.noreply.github.com>

Bukkit/src/main/java/com/plotsquared/bukkit/BukkitPlatform.java

@@ -238,6 +238,16 @@ public final class BukkitPlatform extends JavaPlugin implements Listener, PlotPl
         return this.version;
     }
 
+    @Override
+    public int versionMinHeight() {
+        return serverVersion()[1] >= 18 ? -64 : 0;
+    }
+
+    @Override
+    public int versionMaxHeight() {
+        return serverVersion()[1] >= 18 ? 319 : 255;
+    }
+
     @Override
     public @NonNull String serverImplementation() {
         return Bukkit.getVersion();

Bukkit/src/main/java/com/plotsquared/bukkit/generator/BlockStatePopulator.java

@@ -65,7 +65,10 @@ final class BlockStatePopulator extends BlockPopulator {
             return;
         }
         final ChunkWrapper wrap = new ChunkWrapper(area.getWorldName(), source.getX(), source.getZ());
-        final ScopedQueueCoordinator chunk = this.queue.getForChunk(wrap.x, wrap.z);
+        final ScopedQueueCoordinator chunk = this.queue.getForChunk(wrap.x, wrap.z,
+                com.plotsquared.bukkit.util.BukkitWorld.getMinWorldHeight(world),
+                com.plotsquared.bukkit.util.BukkitWorld.getMaxWorldHeight(world) - 1
+        );
         if (this.plotGenerator.populateChunk(chunk, area)) {
             this.queue.enqueue();
         }

Bukkit/src/main/java/com/plotsquared/bukkit/generator/BukkitPlotGenerator.java

@@ -27,6 +27,7 @@ package com.plotsquared.bukkit.generator;
 
 import com.plotsquared.bukkit.queue.GenChunk;
 import com.plotsquared.bukkit.util.BukkitUtil;
+import com.plotsquared.bukkit.util.BukkitWorld;
 import com.plotsquared.core.PlotSquared;
 import com.plotsquared.core.generator.GeneratorWrapper;
 import com.plotsquared.core.generator.IndependentPlotGenerator;
@@ -159,12 +160,14 @@ public class BukkitPlotGenerator extends ChunkGenerator
             @NonNull BiomeGrid biome
     ) {
 
-        GenChunk result = new GenChunk();
+        int minY = BukkitWorld.getMinWorldHeight(world);
+        int maxY = BukkitWorld.getMaxWorldHeight(world);
+        GenChunk result = new GenChunk(minY, maxY);
         if (this.getPlotGenerator() instanceof SingleWorldGenerator) {
             if (result.getChunkData() != null) {
                 for (int chunkX = 0; chunkX < 16; chunkX++) {
                     for (int chunkZ = 0; chunkZ < 16; chunkZ++) {
-                        for (int y = 0; y < world.getMaxHeight(); y++) {
+                        for (int y = minY; y < maxY; y++) {
                             biome.setBiome(chunkX, y, chunkZ, Biome.PLAINS);
 
                         }

Bukkit/src/main/java/com/plotsquared/bukkit/listener/BlockEventListener.java

@@ -354,7 +354,8 @@ public class BlockEventListener implements Listener {
         Plot plot = area.getPlot(location);
         if (plot != null) {
             BukkitPlayer plotPlayer = BukkitUtil.adapt(player);
-            if (event.getBlock().getY() == 0) {
+            // == rather than <= as we only care about the "ground level" not being destroyed
+            if (event.getBlock().getY() == area.getMinGenHeight()) {
                 if (!Permissions
                         .hasPermission(plotPlayer, Permission.PERMISSION_ADMIN_DESTROY_GROUNDLEVEL)) {
                     plotPlayer.sendMessage(
@@ -649,7 +650,8 @@ public class BlockEventListener implements Listener {
                     event.getBlock().breakNaturally();
                 }
             }
-            if (location.getY() == 0) {
+            // == rather than <= as we only care about the "ground level" not being destroyed
+            if (location.getY() == area.getMinGenHeight()) {
                 event.setCancelled(true);
                 return;
             }

Bukkit/src/main/java/com/plotsquared/bukkit/queue/BukkitChunkCoordinator.java

@@ -74,8 +74,9 @@ public final class BukkitChunkCoordinator extends ChunkCoordinator {
     private final Consumer<Throwable> throwableConsumer;
     private final boolean unloadAfter;
     private final int totalSize;
-
     private final AtomicInteger expectedSize;
+    private final AtomicInteger loadingChunks = new AtomicInteger();
+
     private int batchSize;
     private PlotSquaredTask task;
     private boolean shouldCancel;
@@ -150,6 +151,13 @@ public final class BukkitChunkCoordinator extends ChunkCoordinator {
 
         Chunk chunk = this.availableChunks.poll();
         if (chunk == null) {
+            if (this.availableChunks.isEmpty()) {
+                if (this.requestedChunks.isEmpty() && loadingChunks.get() == 0) {
+                    finish();
+                } else {
+                    requestBatch();
+                }
+            }
             return;
         }
         long[] iterationTime = new long[2];
@@ -197,9 +205,11 @@ public final class BukkitChunkCoordinator extends ChunkCoordinator {
         BlockVector2 chunk;
         for (int i = 0; i < this.batchSize && (chunk = this.requestedChunks.poll()) != null; i++) {
             // This required PaperLib to be bumped to version 1.0.4 to mark the request as urgent
+            loadingChunks.incrementAndGet();
             PaperLib
                     .getChunkAtAsync(this.bukkitWorld, chunk.getX(), chunk.getZ(), true, true)
                     .whenComplete((chunkObject, throwable) -> {
+                        loadingChunks.decrementAndGet();
                         if (throwable != null) {
                             throwable.printStackTrace();
                             // We want one less because this couldn't be processed

Bukkit/src/main/java/com/plotsquared/bukkit/queue/BukkitQueueCoordinator.java

@@ -111,8 +111,8 @@ public class BukkitQueueCoordinator extends BasicQueueCoordinator {
     public boolean enqueue() {
         final Clipboard regenClipboard;
         if (isRegen()) {
-            BlockVector3 start = BlockVector3.at(getRegenStart()[0] << 4, 0, getRegenStart()[1] << 4);
+            BlockVector3 start = BlockVector3.at(getRegenStart()[0] << 4, getMinY(), getRegenStart()[1] << 4);
-            BlockVector3 end = BlockVector3.at((getRegenEnd()[0] << 4) + 15, 255, (getRegenEnd()[1] << 4) + 15);
+            BlockVector3 end = BlockVector3.at((getRegenEnd()[0] << 4) + 15, getMaxY(), (getRegenEnd()[1] << 4) + 15);
             Region region = new CuboidRegion(start, end);
             regenClipboard = new BlockArrayClipboard(region);
             regenClipboard.setOrigin(start);
@@ -134,7 +134,7 @@ public class BukkitQueueCoordinator extends BasicQueueCoordinator {
                 int sx = blockVector2.getX() << 4;
                 int sz = blockVector2.getZ() << 4;
                 if (isRegenChunk) {
-                    for (int layer = 0; layer < 16; layer++) {
+                    for (int layer = getMinLayer(); layer <= getMaxLayer(); layer++) {
                         for (int y = 0; y < 16; y++) {
                             for (int x = 0; x < 16; x++) {
                                 for (int z = 0; z < 16; z++) {
@@ -170,7 +170,7 @@ public class BukkitQueueCoordinator extends BasicQueueCoordinator {
                             int lx = ChunkUtil.getX(j);
                             int lz = ChunkUtil.getZ(j);
                             int x = sx + lx;
-                            int y = ChunkUtil.getY(layer, j);
+                            int y = ChunkUtil.getY(layer + localChunk.getMinSection(), j);
                             int z = sz + lz;
                             boolean edge = Settings.QUEUE.UPDATE_EDGES && isEdge(y >> 4, lx, y & 15, lz, blockVector2,
                                     localChunk
@@ -179,7 +179,7 @@ public class BukkitQueueCoordinator extends BasicQueueCoordinator {
                         }
                     }
                 }
-                for (int layer = 0; layer < localChunk.getBaseblocks().length; layer++) {
+                for (int layer = 0; layer < localChunk.getBiomes().length; layer++) {
                     BiomeType[] biomesLayer = localChunk.getBiomes()[layer];
                     if (biomesLayer == null) {
                         continue;
@@ -295,47 +295,48 @@ public class BukkitQueueCoordinator extends BasicQueueCoordinator {
     }
 
     private boolean isEdge(int layer, int x, int y, int z, BlockVector2 blockVector2, LocalChunk localChunk) {
-        if (layer == 0 || layer == localChunk.getBaseblocks().length - 1) {
+        int layerIndex = (layer - localChunk.getMinSection());
+        if (layer == localChunk.getMinSection() || layerIndex == localChunk.getBaseblocks().length - 1) {
             return false;
         }
         if (x == 0) {
             LocalChunk localChunkX = getBlockChunks().get(blockVector2.withX(blockVector2.getX() - 1));
-            if (localChunkX == null || localChunkX.getBaseblocks()[layer] == null ||
+            if (localChunkX == null || localChunkX.getBaseblocks()[layerIndex] == null ||
-                    localChunkX.getBaseblocks()[layer][ChunkUtil.getJ(15, y, z)] != null) {
+                    localChunkX.getBaseblocks()[layerIndex][ChunkUtil.getJ(15, y, z)] != null) {
                 return true;
             }
         } else if (x == 15) {
             LocalChunk localChunkX = getBlockChunks().get(blockVector2.withX(blockVector2.getX() + 1));
-            if (localChunkX == null || localChunkX.getBaseblocks()[layer] == null ||
+            if (localChunkX == null || localChunkX.getBaseblocks()[layerIndex] == null ||
-                    localChunkX.getBaseblocks()[layer][ChunkUtil.getJ(0, y, z)] != null) {
+                    localChunkX.getBaseblocks()[layerIndex][ChunkUtil.getJ(0, y, z)] != null) {
                 return true;
             }
         }
         if (z == 0) {
             LocalChunk localChunkZ = getBlockChunks().get(blockVector2.withZ(blockVector2.getZ() - 1));
-            if (localChunkZ == null || localChunkZ.getBaseblocks()[layer] == null ||
+            if (localChunkZ == null || localChunkZ.getBaseblocks()[layerIndex] == null ||
-                    localChunkZ.getBaseblocks()[layer][ChunkUtil.getJ(x, y, 15)] != null) {
+                    localChunkZ.getBaseblocks()[layerIndex][ChunkUtil.getJ(x, y, 15)] != null) {
                 return true;
             }
         } else if (z == 15) {
             LocalChunk localChunkZ = getBlockChunks().get(blockVector2.withZ(blockVector2.getZ() + 1));
-            if (localChunkZ == null || localChunkZ.getBaseblocks()[layer] == null ||
+            if (localChunkZ == null || localChunkZ.getBaseblocks()[layerIndex] == null ||
-                    localChunkZ.getBaseblocks()[layer][ChunkUtil.getJ(x, y, 0)] != null) {
+                    localChunkZ.getBaseblocks()[layerIndex][ChunkUtil.getJ(x, y, 0)] != null) {
                 return true;
             }
         }
         if (y == 0) {
-            if (localChunk.getBaseblocks()[layer - 1] == null ||
+            if (localChunk.getBaseblocks()[layerIndex - 1] == null ||
-                    localChunk.getBaseblocks()[layer][ChunkUtil.getJ(x, 15, z)] != null) {
+                    localChunk.getBaseblocks()[layerIndex][ChunkUtil.getJ(x, 15, z)] != null) {
                 return true;
             }
         } else if (y == 15) {
-            if (localChunk.getBaseblocks()[layer + 1] == null ||
+            if (localChunk.getBaseblocks()[layerIndex + 1] == null ||
-                    localChunk.getBaseblocks()[layer][ChunkUtil.getJ(x, 0, z)] != null) {
+                    localChunk.getBaseblocks()[layerIndex][ChunkUtil.getJ(x, 0, z)] != null) {
                 return true;
             }
         }
-        BaseBlock[] baseBlocks = localChunk.getBaseblocks()[layer];
+        BaseBlock[] baseBlocks = localChunk.getBaseblocks()[layerIndex];
         if (x > 0 && baseBlocks[ChunkUtil.getJ(x - 1, y, z)] == null) {
             return true;
         }

Bukkit/src/main/java/com/plotsquared/bukkit/queue/GenChunk.java

@@ -31,6 +31,7 @@ import com.plotsquared.bukkit.util.BukkitUtil;
 import com.plotsquared.core.location.ChunkWrapper;
 import com.plotsquared.core.location.Location;
 import com.plotsquared.core.queue.ScopedQueueCoordinator;
+import com.plotsquared.core.util.AnnotationHelper;
 import com.plotsquared.core.util.ChunkUtil;
 import com.plotsquared.core.util.PatternUtil;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
@@ -50,6 +51,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.util.Arrays;
 
+@AnnotationHelper.ApiDescription(info = "Internal use only. Subject to changes at any time.")
 public class GenChunk extends ScopedQueueCoordinator {
 
     public final Biome[] biomes;
@@ -61,8 +63,14 @@ public class GenChunk extends ScopedQueueCoordinator {
     public int chunkZ;
     private ChunkData chunkData = null;
 
-    public GenChunk() {
+    /**
-        super(null, Location.at("", 0, 0, 0), Location.at("", 15, 255, 15));
+     * @param minY minimum world Y, inclusive
+     * @param maxY maximum world Y, inclusive
+     *
+     * @since TODO
+     */
+    public GenChunk(int minY, int maxY) {
+        super(null, Location.at("", 0, minY, 0), Location.at("", 15, maxY, 15));
         this.biomes = Biome.values();
     }
 
@@ -117,7 +125,7 @@ public class GenChunk extends ScopedQueueCoordinator {
             return;
         }
         Biome biome = BukkitAdapter.adapt(biomeType);
-        for (int y = 0; y < 256; y++) {
+        for (int y = getMin().getY(); y <= getMax().getY(); y++) {
             for (int x = 0; x < 16; x++) {
                 for (int z = 0; z < 16; z++) {
                     this.biomeGrid.setBiome(x, y, z, biome);
@@ -130,7 +138,7 @@ public class GenChunk extends ScopedQueueCoordinator {
     public void setCuboid(@NonNull Location pos1, @NonNull Location pos2, @NonNull BlockState block) {
         if (result != null && pos1.getX() == 0 && pos1.getZ() == 0 && pos2.getX() == 15 && pos2.getZ() == 15) {
             for (int y = pos1.getY(); y <= pos2.getY(); y++) {
-                int layer = y >> 4;
+                int layer = getLayerIndex(y);
                 BlockState[] data = result[layer];
                 if (data == null) {
                     result[layer] = data = new BlockState[4096];
@@ -164,7 +172,7 @@ public class GenChunk extends ScopedQueueCoordinator {
      */
     public boolean setBiome(int x, int z, @NonNull Biome biome) {
         if (this.biomeGrid != null) {
-            for (int y = 0; y < 256; y++) {
+            for (int y = getMin().getY(); y <= getMax().getY(); y++) {
                 this.setBiome(x, y, z, biome);
             }
             return true;
@@ -197,7 +205,7 @@ public class GenChunk extends ScopedQueueCoordinator {
     }
 
     private void storeCache(final int x, final int y, final int z, final @NonNull BlockState id) {
-        int i = y >> 4;
+        int i = getLayerIndex(y);
         BlockState[] v = this.result[i];
         if (v == null) {
             this.result[i] = v = new BlockState[4096];
@@ -219,7 +227,7 @@ public class GenChunk extends ScopedQueueCoordinator {
 
     @Override
     public @Nullable BlockState getBlock(int x, int y, int z) {
-        int i = y >> 4;
+        int i = getLayerIndex(y);
         if (result == null) {
             return BukkitBlockUtil.get(chunkData.getType(x, y, z));
         }
@@ -246,16 +254,16 @@ public class GenChunk extends ScopedQueueCoordinator {
 
     @Override
     public @NonNull Location getMax() {
-        return Location.at(getWorld().getName(), 15 + (getX() << 4), 255, 15 + (getZ() << 4));
+        return Location.at(getWorld().getName(), 15 + (getX() << 4), super.getMax().getY(), 15 + (getZ() << 4));
     }
 
     @Override
     public @NonNull Location getMin() {
-        return Location.at(getWorld().getName(), getX() << 4, 0, getZ() << 4);
+        return Location.at(getWorld().getName(), getX() << 4, super.getMin().getY(), getZ() << 4);
     }
 
     public @NonNull GenChunk clone() {
-        GenChunk toReturn = new GenChunk();
+        GenChunk toReturn = new GenChunk(getMin().getY(), getMax().getY());
         if (this.result != null) {
             for (int i = 0; i < this.result.length; i++) {
                 BlockState[] matrix = this.result[i];
@@ -269,4 +277,8 @@ public class GenChunk extends ScopedQueueCoordinator {
         return toReturn;
     }
 
+    private int getLayerIndex(int y) {
+        return (y - getMin().getY()) >> 4;
+    }
+
 }

Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitRegionManager.java

@@ -40,7 +40,6 @@ import com.plotsquared.core.queue.QueueCoordinator;
 import com.plotsquared.core.queue.ScopedQueueCoordinator;
 import com.plotsquared.core.util.ChunkManager;
 import com.plotsquared.core.util.RegionManager;
-import com.plotsquared.core.util.RegionUtil;
 import com.plotsquared.core.util.WorldUtil;
 import com.plotsquared.core.util.entity.EntityCategories;
 import com.plotsquared.core.util.task.RunnableVal;
@@ -261,7 +260,7 @@ public class BukkitRegionManager extends RegionManager {
             if (checkX2 && checkZ2) {
                 map.saveRegion(world, xxt2, xxt, zzt2, zzt); //
             }
-            CuboidRegion currentPlotClear = RegionUtil.createRegion(pos1.getX(), pos2.getX(), pos1.getZ(), pos2.getZ());
+            CuboidRegion currentPlotClear = new CuboidRegion(pos1.getBlockVector3(), pos2.getBlockVector3());
             map.saveEntitiesOut(Bukkit.getWorld(world.getName()).getChunkAt(x, z), currentPlotClear);
             AugmentedUtils.bypass(
                     ignoreAugment,
@@ -276,7 +275,9 @@ public class BukkitRegionManager extends RegionManager {
                                     PlotLoc plotLoc = new PlotLoc(bx + x1, bz + z1);
                                     BaseBlock[] ids = map.allBlocks.get(plotLoc);
                                     if (ids != null) {
-                                        for (int y = 0; y < Math.min(128, ids.length); y++) {
+                                        int minY = value.getMin().getY();
+                                        for (int yIndex = 0; yIndex < ids.length; yIndex++) {
+                                            int y = yIndex + minY;
                                             BaseBlock id = ids[y];
                                             if (id != null) {
                                                 value.setBlock(x1, y, z1, id);
@@ -284,12 +285,6 @@ public class BukkitRegionManager extends RegionManager {
                                                 value.setBlock(x1, y, z1, BlockTypes.AIR.getDefaultState());
                                             }
                                         }
-                                        for (int y = Math.min(128, ids.length); y < ids.length; y++) {
-                                            BaseBlock id = ids[y];
-                                            if (id != null) {
-                                                value.setBlock(x1, y, z1, id);
-                                            }
-                                        }
                                     }
                                 }
                             }
@@ -297,7 +292,7 @@ public class BukkitRegionManager extends RegionManager {
                     }, world.getName(), chunk)
             );
             //map.restoreBlocks(worldObj, 0, 0);
-            map.restoreEntities(Bukkit.getWorld(world.getName()), 0, 0);
+            map.restoreEntities(Bukkit.getWorld(world.getName()));
         });
         regenQueue.setCompleteTask(whenDone);
         queue.setCompleteTask(regenQueue::enqueue);

Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitUtil.java

@@ -44,7 +44,6 @@ import com.plotsquared.core.util.task.TaskManager;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
 import com.sk89q.worldedit.bukkit.BukkitWorld;
 import com.sk89q.worldedit.math.BlockVector2;
-import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BlockCategories;
 import com.sk89q.worldedit.world.block.BlockState;
@@ -61,7 +60,6 @@ import org.bukkit.Bukkit;
 import org.bukkit.Chunk;
 import org.bukkit.Material;
 import org.bukkit.World;
-import org.bukkit.block.Biome;
 import org.bukkit.block.Block;
 import org.bukkit.block.BlockFace;
 import org.bukkit.block.Sign;
@@ -246,7 +244,9 @@ public class BukkitUtil extends WorldUtil {
             final World bukkitWorld = Objects.requireNonNull(getWorld(world));
             // Skip top and bottom block
             int air = 1;
-            for (int y = bukkitWorld.getMaxHeight() - 1; y >= 0; y--) {
+            int maxY = com.plotsquared.bukkit.util.BukkitWorld.getMaxWorldHeight(bukkitWorld);
+            int minY = com.plotsquared.bukkit.util.BukkitWorld.getMinWorldHeight(bukkitWorld);
+            for (int y = maxY - 1; y >= minY; y--) {
                 Block block = bukkitWorld.getBlockAt(x, y, z);
                 Material type = block.getType();
                 if (type.isSolid()) {
@@ -273,7 +273,9 @@ public class BukkitUtil extends WorldUtil {
         final World bukkitWorld = Objects.requireNonNull(getWorld(world));
         // Skip top and bottom block
         int air = 1;
-        for (int y = bukkitWorld.getMaxHeight() - 1; y >= 0; y--) {
+        int maxY = com.plotsquared.bukkit.util.BukkitWorld.getMaxWorldHeight(bukkitWorld);
+        int minY = com.plotsquared.bukkit.util.BukkitWorld.getMinWorldHeight(bukkitWorld);
+        for (int y = maxY - 1; y >= minY; y--) {
             Block block = bukkitWorld.getBlockAt(x, y, z);
             Material type = block.getType();
             if (type.isSolid()) {
@@ -371,7 +373,7 @@ public class BukkitUtil extends WorldUtil {
                     sign.setLine(i, LEGACY_COMPONENT_SERIALIZER
                             .serialize(MINI_MESSAGE.parse(lines[i].getComponent(LocaleHolder.console()), replacements)));
                 }
-                sign.update(true);
+                sign.update(true, false);
             }
         });
     }
@@ -382,27 +384,6 @@ public class BukkitUtil extends WorldUtil {
         return new StringComparison<BlockState>().new ComparisonResult(1, state);
     }
 
-    @Override
-    public void setBiomes(
-            final @NonNull String worldName,
-            final @NonNull CuboidRegion region,
-            final @NonNull BiomeType biomeType
-    ) {
-        final World world = getWorld(worldName);
-        if (world == null) {
-            LOGGER.warn("An error occurred while setting the biome because the world was null", new RuntimeException());
-            return;
-        }
-        final Biome biome = BukkitAdapter.adapt(biomeType);
-        for (int x = region.getMinimumPoint().getX(); x <= region.getMaximumPoint().getX(); x++) {
-            for (int z = region.getMinimumPoint().getZ(); z <= region.getMaximumPoint().getZ(); z++) {
-                if (world.getBiome(x, z) != biome) {
-                    world.setBiome(x, z, biome);
-                }
-            }
-        }
-    }
-
     @Override
     public com.sk89q.worldedit.world.@NonNull World getWeWorld(final @NonNull String world) {
         return new BukkitWorld(Bukkit.getWorld(world));

Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitWorld.java

@@ -36,6 +36,18 @@ import java.util.Objects;
 public class BukkitWorld implements World<org.bukkit.World> {
 
     private static final Map<String, BukkitWorld> worldMap = Maps.newHashMap();
+    private static final boolean HAS_MIN_Y;
+
+    static {
+        boolean temp;
+        try {
+            org.bukkit.World.class.getMethod("getMinHeight");
+            temp = true;
+        } catch (NoSuchMethodException e) {
+            temp = false;
+        }
+        HAS_MIN_Y = temp;
+    }
 
     private final org.bukkit.World world;
 
@@ -73,6 +85,24 @@ public class BukkitWorld implements World<org.bukkit.World> {
         return bukkitWorld;
     }
 
+    /**
+     * Get the min world height from a Bukkit {@link org.bukkit.World}. Inclusive
+     *
+     * @since TODO
+     */
+    public static int getMinWorldHeight(org.bukkit.World world) {
+        return HAS_MIN_Y ? world.getMinHeight() : 0;
+    }
+
+    /**
+     * Get the max world height from a Bukkit {@link org.bukkit.World}. Exclusive
+     *
+     * @since TODO
+     */
+    public static int getMaxWorldHeight(org.bukkit.World world) {
+        return HAS_MIN_Y ? world.getMaxHeight() : 256;
+    }
+
     @Override
     public org.bukkit.World getPlatformWorld() {
         return this.world;
@@ -83,6 +113,16 @@ public class BukkitWorld implements World<org.bukkit.World> {
         return this.world.getName();
     }
 
+    @Override
+    public int getMinHeight() {
+        return getMinWorldHeight(world);
+    }
+
+    @Override
+    public int getMaxHeight() {
+        return getMaxWorldHeight(world) - 1;
+    }
+
     @Override
     public boolean equals(final Object o) {
         if (this == o) {

Bukkit/src/main/java/com/plotsquared/bukkit/util/ContentMap.java

@@ -70,7 +70,7 @@ public class ContentMap {
         }
         for (int x = x1; x <= x2; x++) {
             for (int z = z1; z <= z2; z++) {
-                saveBlocks(world, 256, x, z, 0, 0);
+                saveBlocks(world, x, z);
             }
         }
     }
@@ -92,14 +92,7 @@ public class ContentMap {
         }
     }
 
-    void saveEntitiesIn(Chunk chunk, CuboidRegion region) {
+    void saveEntitiesIn(Chunk chunk, CuboidRegion region, boolean delete) {
-        saveEntitiesIn(chunk, region, 0, 0, false);
-    }
-
-    void saveEntitiesIn(
-            Chunk chunk, CuboidRegion region, int offsetX, int offsetZ,
-            boolean delete
-    ) {
         for (Entity entity : chunk.getEntities()) {
             Location location = BukkitUtil.adapt(entity.getLocation());
             int x = location.getX();
@@ -111,8 +104,6 @@ public class ContentMap {
                 continue;
             }
             EntityWrapper wrap = new ReplicatingEntityWrapper(entity, (short) 2);
-            wrap.x += offsetX;
-            wrap.z += offsetZ;
             wrap.saveEntity();
             this.entities.add(wrap);
             if (delete) {
@@ -123,10 +114,10 @@ public class ContentMap {
         }
     }
 
-    void restoreEntities(World world, int xOffset, int zOffset) {
+    void restoreEntities(World world) {
         for (EntityWrapper entity : this.entities) {
             try {
-                entity.spawn(world, xOffset, zOffset);
+                entity.spawn(world, 0, 0);
             } catch (Exception e) {
                 LOGGER.error("Failed to restore entity", e);
             }
@@ -134,15 +125,13 @@ public class ContentMap {
         this.entities.clear();
     }
 
-    //todo optimize maxY
+    private void saveBlocks(BukkitWorld world, int x, int z) {
-    void saveBlocks(BukkitWorld world, int maxY, int x, int z, int offsetX, int offsetZ) {
+        BaseBlock[] ids = new BaseBlock[world.getMaxY() - world.getMinY() + 1];
-        maxY = Math.min(255, maxY);
+        for (short yIndex = 0; yIndex <= world.getMaxY() - world.getMinY(); yIndex++) {
-        BaseBlock[] ids = new BaseBlock[maxY + 1];
+            BaseBlock block = world.getFullBlock(BlockVector3.at(x, yIndex + world.getMinY(), z));
-        for (short y = 0; y <= maxY; y++) {
+            ids[yIndex] = block;
-            BaseBlock block = world.getFullBlock(BlockVector3.at(x, y, z));
-            ids[y] = block;
         }
-        PlotLoc loc = new PlotLoc(x + offsetX, z + offsetZ);
+        PlotLoc loc = new PlotLoc(x, z);
         this.allBlocks.put(loc, ids);
     }
 

Bukkit/src/main/java/com/plotsquared/bukkit/util/fawe/FaweRegionManager.java

@@ -110,6 +110,11 @@ public class FaweRegionManager extends BukkitRegionManager {
         delegate.setBiome(region, extendBiome, biome, world, whenDone);
     }
 
+    @Override
+    public void setBiome(CuboidRegion region, int extendBiome, BiomeType biome, PlotArea area, Runnable whenDone) {
+        delegate.setBiome(region, extendBiome, biome, area.getWorldName(), whenDone);
+    }
+
     @Override
     public boolean copyRegion(
             final @NonNull Location pos1,

Core/src/main/java/com/plotsquared/core/PlotPlatform.java

@@ -98,6 +98,22 @@ public interface PlotPlatform<P> extends LocaleHolder {
      */
     int[] serverVersion();
 
+    /**
+     * Gets the default minimum world height for the version of Minecraft that the server is running.
+     *
+     * @return minimum world height
+     * @since TODO
+     */
+    int versionMinHeight();
+
+    /**
+     * Gets the default maximum world height for the version of Minecraft that the server is running.
+     *
+     * @return maximum world height (inclusive)
+     * @since TODO
+     */
+    int versionMaxHeight();
+
     /**
      * Gets the server implementation name and version
      *

Core/src/main/java/com/plotsquared/core/PlotSquared.java

@@ -1020,8 +1020,8 @@ public class PlotSquared {
             // save configuration
 
             final List<String> validArguments = Arrays
-                    .asList("s=", "size=", "g=", "gap=", "h=", "height=", "f=", "floor=", "m=", "main=",
+                    .asList("s=", "size=", "g=", "gap=", "h=", "height=", "minh=", "minheight=", "maxh=", "maxheight=",
-                            "w=", "wall=", "b=", "border="
+                            "f=", "floor=", "m=", "main=", "w=", "wall=", "b=", "border="
                     );
 
             // Calculate the number of expected arguments
@@ -1100,6 +1100,14 @@ public class PlotSquared {
                                     ConfigurationUtil.INTEGER.parseString(value).shortValue()
                             );
                         }
+                        case "minh", "minheight" -> this.worldConfiguration.set(
+                                base + "world.min_gen_height",
+                                ConfigurationUtil.INTEGER.parseString(value).shortValue()
+                        );
+                        case "maxh", "maxheight" -> this.worldConfiguration.set(
+                                base + "world.max_gen_height",
+                                ConfigurationUtil.INTEGER.parseString(value).shortValue()
+                        );
                         case "f", "floor" -> this.worldConfiguration.set(
                                 base + "plot.floor",
                                 ConfigurationUtil.BLOCK_BUCKET.parseString(value).toString()

Core/src/main/java/com/plotsquared/core/command/Area.java

@@ -75,6 +75,7 @@ import com.sk89q.worldedit.function.operation.Operations;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.world.World;
 import net.kyori.adventure.text.minimessage.Template;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
@@ -191,11 +192,12 @@ public class Area extends SubCommand {
                 final BlockVector3 playerSelectionMin = playerSelectedRegion.getMinimumPoint();
                 final BlockVector3 playerSelectionMax = playerSelectedRegion.getMaximumPoint();
                 // Create a new selection that spans the entire vertical range of the world
+                World world = playerSelectedRegion.getWorld();
                 final CuboidRegion selectedRegion =
                         new CuboidRegion(
                                 playerSelectedRegion.getWorld(),
-                                BlockVector3.at(playerSelectionMin.getX(), 0, playerSelectionMin.getZ()),
+                                BlockVector3.at(playerSelectionMin.getX(), world.getMinY(), playerSelectionMin.getZ()),
-                                BlockVector3.at(playerSelectionMax.getX(), 255, playerSelectionMax.getZ())
+                                BlockVector3.at(playerSelectionMax.getX(), world.getMaxY(), playerSelectionMax.getZ())
                         );
                 // There's only one plot in the area...
                 final PlotId plotId = PlotId.of(1, 1);
@@ -278,9 +280,9 @@ public class Area extends SubCommand {
                     if (offsetZ != 0) {
                         this.worldConfiguration.set(path + ".road.offset.z", offsetZ);
                     }
-                    final String world = this.setupUtils.setupWorld(singleBuilder);
+                    final String worldName = this.setupUtils.setupWorld(singleBuilder);
-                    if (this.worldUtil.isWorld(world)) {
+                    if (this.worldUtil.isWorld(worldName)) {
-                        PlotSquared.get().loadWorld(world, null);
+                        PlotSquared.get().loadWorld(worldName, null);
                         player.sendMessage(TranslatableCaption.of("single.single_area_created"));
                     } else {
                         player.sendMessage(
@@ -369,7 +371,8 @@ public class Area extends SubCommand {
                                 int lower = (area.ROAD_WIDTH & 1) == 0 ? area.ROAD_WIDTH / 2 - 1 : area.ROAD_WIDTH / 2;
                                 final int offsetX = bx - (area.ROAD_WIDTH == 0 ? 0 : lower);
                                 final int offsetZ = bz - (area.ROAD_WIDTH == 0 ? 0 : lower);
-                                final CuboidRegion region = RegionUtil.createRegion(bx, tx, bz, tz);
+                                // Height doesn't matter for this region
+                                final CuboidRegion region = RegionUtil.createRegion(bx, tx, 0, 0, bz, tz);
                                 final Set<PlotArea> areas = this.plotAreaManager.getPlotAreasSet(area.getWorldName(), region);
                                 if (!areas.isEmpty()) {
                                     player.sendMessage(

Core/src/main/java/com/plotsquared/core/command/DebugExec.java

@@ -49,6 +49,7 @@ import org.checkerframework.checker.nullness.qual.NonNull;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.stream.Collectors;
@@ -207,7 +208,7 @@ public class DebugExec extends SubCommand {
                     }
                     boolean result;
                     if (HybridUtils.regions != null) {
-                        result = this.hybridUtils.scheduleRoadUpdate(area, HybridUtils.regions, 0, new HashSet<>());
+                        result = this.hybridUtils.scheduleRoadUpdate(area, HybridUtils.regions, 0, new LinkedHashSet<>());
                     } else {
                         result = this.hybridUtils.scheduleRoadUpdate(area, 0);
                     }

Core/src/main/java/com/plotsquared/core/command/Save.java

@@ -104,8 +104,8 @@ public class Save extends SubCommand {
                     TaskManager.runTaskAsync(() -> {
                         String time = (System.currentTimeMillis() / 1000) + "";
                         Location[] corners = plot.getCorners();
-                        corners[0] = corners[0].withY(0);
+                        corners[0] = corners[0].withY(plot.getArea().getMinBuildHeight());
-                        corners[1] = corners[1].withY(255);
+                        corners[1] = corners[1].withY(plot.getArea().getMaxBuildHeight());
                         int size = (corners[1].getX() - corners[0].getX()) + 1;
                         PlotId id = plot.getId();
                         String world1 = plot.getArea().toString().replaceAll(";", "-")

Core/src/main/java/com/plotsquared/core/command/Trim.java

@@ -180,12 +180,12 @@ public class Trim extends SubCommand {
                             int bx = cbx << 4;
                             int bz = cbz << 4;
                             CuboidRegion region =
-                                    RegionUtil.createRegion(bx, bx + 511, bz, bz + 511);
+                                    RegionUtil.createRegion(bx, bx + 511, 0, 0, bz, bz + 511);
                             for (Plot plot : PlotQuery.newQuery().inWorld(world)) {
                                 Location bot = plot.getBottomAbs();
                                 Location top = plot.getExtendedTopAbs();
                                 CuboidRegion plotReg = RegionUtil
-                                        .createRegion(bot.getX(), top.getX(), bot.getZ(), top.getZ());
+                                        .createRegion(bot.getX(), top.getX(), 0, 0, bot.getZ(), top.getZ());
                                 if (!RegionUtil.intersects(region, plotReg)) {
                                     continue;
                                 }

Core/src/main/java/com/plotsquared/core/generator/AugmentedUtils.java

@@ -70,7 +70,7 @@ public class AugmentedUtils {
         final int blockZ = chunkZ << 4;
         // Create a region that contains the
         // entire chunk
-        CuboidRegion region = RegionUtil.createRegion(blockX, blockX + 15, blockZ, blockZ + 15);
+        CuboidRegion region = RegionUtil.createRegion(blockX, blockX + 15, 0, 0, blockZ, blockZ + 15);
         // Query for plot areas in the chunk
         final Set<PlotArea> areas = PlotSquared.get().getPlotAreaManager().getPlotAreasSet(world, region);
         if (areas.isEmpty()) {
@@ -122,6 +122,7 @@ public class AugmentedUtils {
             }
             QueueCoordinator secondaryMask;
             BlockState air = BlockTypes.AIR.getDefaultState();
+            int startYOffset = !(area instanceof ClassicPlotWorld) || ((ClassicPlotWorld) area).PLOT_BEDROCK ? 1 : 0;
             if (area.getTerrain() == PlotAreaTerrainType.ROAD) {
                 PlotManager manager = area.getPlotManager();
                 final boolean[][] canPlace = new boolean[16][16];
@@ -132,7 +133,7 @@ public class AugmentedUtils {
                         int worldZ = z + blockZ;
                         boolean can = manager.getPlotId(worldX, 0, worldZ) == null;
                         if (can) {
-                            for (int y = 1; y < 128; y++) {
+                            for (int y = area.getMinGenHeight() + startYOffset; y <= area.getMaxGenHeight(); y++) {
                                 queue.setBlock(worldX, y, worldZ, air);
                             }
                             canPlace[x][z] = true;
@@ -149,7 +150,7 @@ public class AugmentedUtils {
                 secondaryMask = primaryMask;
                 for (int x = relativeBottomX; x <= relativeTopX; x++) {
                     for (int z = relativeBottomZ; z <= relativeTopZ; z++) {
-                        for (int y = 1; y < 128; y++) {
+                        for (int y = area.getMinGenHeight() + startYOffset; y <= area.getMaxGenHeight(); y++) {
                             queue.setBlock(blockX + x, y, blockZ + z, air);
                         }
                     }
@@ -166,8 +167,8 @@ public class AugmentedUtils {
             ScopedQueueCoordinator scoped =
                     new ScopedQueueCoordinator(
                             secondaryMask,
-                            Location.at(world, blockX, 0, blockZ),
+                            Location.at(world, blockX, area.getMinGenHeight(), blockZ),
-                            Location.at(world, blockX + 15, 255, blockZ + 15)
+                            Location.at(world, blockX + 15, area.getMaxGenHeight(), blockZ + 15)
                     );
             generator.generateChunk(scoped, area);
             generator.populateChunk(scoped, area);

Core/src/main/java/com/plotsquared/core/generator/ClassicPlotManager.java

@@ -37,7 +37,6 @@ import com.plotsquared.core.plot.Plot;
 import com.plotsquared.core.plot.PlotAreaTerrainType;
 import com.plotsquared.core.plot.PlotId;
 import com.plotsquared.core.queue.QueueCoordinator;
-import com.plotsquared.core.util.BlockUtil;
 import com.plotsquared.core.util.MathMan;
 import com.plotsquared.core.util.RegionManager;
 import com.plotsquared.core.util.task.TaskManager;
@@ -147,7 +146,15 @@ public class ClassicPlotManager extends SquarePlotManager {
     ) {
         Plot plot = classicPlotWorld.getPlotAbs(plotId);
         if (plot != null && plot.isBasePlot()) {
-            return this.regionManager.setCuboids(classicPlotWorld, plot.getRegions(), blocks, 1, getWorldHeight(), actor, queue);
+            return this.regionManager.setCuboids(
+                    classicPlotWorld,
+                    plot.getRegions(),
+                    blocks,
+                    classicPlotWorld.getMinBuildHeight(),
+                    classicPlotWorld.getMaxBuildHeight(),
+                    actor,
+                    queue
+            );
         }
         return false;
     }
@@ -175,7 +182,7 @@ public class ClassicPlotManager extends SquarePlotManager {
                             plot.getRegions(),
                             blocks,
                             classicPlotWorld.PLOT_HEIGHT + 1,
-                            getWorldHeight(),
+                            classicPlotWorld.getMaxBuildHeight(),
                             actor,
                             queue
                     );
@@ -204,7 +211,7 @@ public class ClassicPlotManager extends SquarePlotManager {
                     classicPlotWorld,
                     plot.getRegions(),
                     blocks,
-                    1,
+                    classicPlotWorld.getMinBuildHeight(),
                     classicPlotWorld.PLOT_HEIGHT - 1,
                     actor,
                     queue
@@ -281,7 +288,7 @@ public class ClassicPlotManager extends SquarePlotManager {
             }
         }
 
-        int maxY = classicPlotWorld.getPlotManager().getWorldHeight();
+        int maxY = classicPlotWorld.getMaxBuildHeight();
         if (!plot.isMerged(Direction.NORTH)) {
             int z = bottom.getZ();
             for (int x = bottom.getX(); x <= top.getX(); x++) {
@@ -382,7 +389,7 @@ public class ClassicPlotManager extends SquarePlotManager {
         if (!plot.isMerged(Direction.NORTH)) {
             int z = bot.getZ();
             for (int x = bot.getX(); x < top.getX(); x++) {
-                for (int y = 1; y <= classicPlotWorld.WALL_HEIGHT; y++) {
+                for (int y = classicPlotWorld.getMaxBuildHeight(); y <= classicPlotWorld.WALL_HEIGHT; y++) {
                     queue.setBlock(x, y, z, blocks);
                 }
             }
@@ -390,7 +397,7 @@ public class ClassicPlotManager extends SquarePlotManager {
         if (!plot.isMerged(Direction.WEST)) {
             int x = bot.getX();
             for (int z = bot.getZ(); z < top.getZ(); z++) {
-                for (int y = 1; y <= classicPlotWorld.WALL_HEIGHT; y++) {
+                for (int y = classicPlotWorld.getMinBuildHeight(); y <= classicPlotWorld.WALL_HEIGHT; y++) {
                     queue.setBlock(x, y, z, blocks);
                 }
             }
@@ -398,7 +405,7 @@ public class ClassicPlotManager extends SquarePlotManager {
         if (!plot.isMerged(Direction.SOUTH)) {
             int z = top.getZ();
             for (int x = bot.getX(); x < top.getX() + (plot.isMerged(Direction.EAST) ? 0 : 1); x++) {
-                for (int y = 1; y <= classicPlotWorld.WALL_HEIGHT; y++) {
+                for (int y = classicPlotWorld.getMinBuildHeight(); y <= classicPlotWorld.WALL_HEIGHT; y++) {
                     queue.setBlock(x, y, z, blocks);
                 }
             }
@@ -406,7 +413,7 @@ public class ClassicPlotManager extends SquarePlotManager {
         if (!plot.isMerged(Direction.EAST)) {
             int x = top.getX();
             for (int z = bot.getZ(); z < top.getZ() + (plot.isMerged(Direction.SOUTH) ? 0 : 1); z++) {
-                for (int y = 1; y <= classicPlotWorld.WALL_HEIGHT; y++) {
+                for (int y = classicPlotWorld.getMinBuildHeight(); y <= classicPlotWorld.WALL_HEIGHT; y++) {
                     queue.setBlock(x, y, z, blocks);
                 }
             }
@@ -501,7 +508,7 @@ public class ClassicPlotManager extends SquarePlotManager {
             enqueue = true;
         }
 
-        int maxY = getWorldHeight();
+        int maxY = classicPlotWorld.getMaxGenHeight();
         queue.setCuboid(
                 Location.at(
                         classicPlotWorld.getWorldName(),
@@ -513,27 +520,27 @@ public class ClassicPlotManager extends SquarePlotManager {
         );
         if (classicPlotWorld.PLOT_BEDROCK) {
             queue.setCuboid(
-                    Location.at(classicPlotWorld.getWorldName(), sx, 0, sz + 1),
+                    Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.getMinGenHeight(), sz + 1),
-                    Location.at(classicPlotWorld.getWorldName(), ex, 0, ez - 1),
+                    Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getMinGenHeight(), ez - 1),
                     BlockTypes.BEDROCK.getDefaultState()
             );
-            queue.setCuboid(
-                    Location.at(classicPlotWorld.getWorldName(), sx, 1, sz + 1),
-                    Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.WALL_HEIGHT, ez - 1),
-                    classicPlotWorld.WALL_FILLING.toPattern()
-            );
-        } else {
-            queue.setCuboid(
-                    Location.at(classicPlotWorld.getWorldName(), sx, 0, sz + 1),
-                    Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.WALL_HEIGHT, ez - 1),
-                    classicPlotWorld.WALL_FILLING.toPattern()
-            );
         }
+        int startYOffset = classicPlotWorld.PLOT_BEDROCK ? 1 : 0;
         queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx, 1, sz + 1),
+                Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getMinGenHeight() + startYOffset, sz + 1),
+                Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.WALL_HEIGHT, ez - 1),
+                classicPlotWorld.WALL_FILLING.toPattern()
+        );
+        queue.setCuboid(
+                Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.getMinGenHeight() + startYOffset, sz + 1),
                 Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.WALL_HEIGHT, ez - 1),
                 classicPlotWorld.WALL_FILLING.toPattern()
         );
+        queue.setCuboid(
+                Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight() + startYOffset, sz + 1),
+                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.ROAD_HEIGHT, ez - 1),
+                classicPlotWorld.ROAD_BLOCK.toPattern()
+        );
 
         if (classicPlotWorld.PLACE_TOP_BLOCK) {
             queue.setCuboid(
@@ -541,24 +548,12 @@ public class ClassicPlotManager extends SquarePlotManager {
                     Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.WALL_HEIGHT + 1, ez - 1),
                     classicPlotWorld.WALL_BLOCK.toPattern()
             );
-        }
-        queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), ex, 1, sz + 1),
-                Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.WALL_HEIGHT, ez - 1),
-                classicPlotWorld.WALL_FILLING.toPattern()
-        );
-        if (classicPlotWorld.PLACE_TOP_BLOCK) {
             queue.setCuboid(
                     Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.WALL_HEIGHT + 1, sz + 1),
                     Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.WALL_HEIGHT + 1, ez - 1),
                     classicPlotWorld.WALL_BLOCK.toPattern()
             );
         }
-        queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 1, sz + 1),
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.ROAD_HEIGHT, ez - 1),
-                classicPlotWorld.ROAD_BLOCK.toPattern()
-        );
         return !enqueue || queue.enqueue();
     }
 
@@ -584,19 +579,32 @@ public class ClassicPlotManager extends SquarePlotManager {
                         classicPlotWorld.schematicStartHeight() + 1,
                         sz
                 ),
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.getPlotManager().getWorldHeight(), ez),
+                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.getMaxGenHeight(), ez),
                 BlockTypes.AIR.getDefaultState()
         );
+        if (classicPlotWorld.PLOT_BEDROCK) {
+            queue.setCuboid(
+                    Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight(), sz),
+                    Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.getMinGenHeight(), ez),
+                    BlockTypes.BEDROCK.getDefaultState()
+            );
+        }
+        int startYOffset = classicPlotWorld.PLOT_BEDROCK ? 1 : 0;
         queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 0, sz),
+                Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight() + startYOffset, sz),
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, 0, ez),
-                BlockUtil.get((short) 7, (byte) 0)
-        );
-        queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 1, sz),
                 Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.WALL_HEIGHT, sz),
                 classicPlotWorld.WALL_FILLING.toPattern()
         );
+        queue.setCuboid(
+                Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight() + startYOffset, ez),
+                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.WALL_HEIGHT, ez),
+                classicPlotWorld.WALL_FILLING.toPattern()
+        );
+        queue.setCuboid(
+                Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight() + startYOffset, sz + 1),
+                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.ROAD_HEIGHT, ez - 1),
+                classicPlotWorld.ROAD_BLOCK.toPattern()
+        );
 
         if (classicPlotWorld.PLACE_TOP_BLOCK) {
             queue.setCuboid(
@@ -604,24 +612,12 @@ public class ClassicPlotManager extends SquarePlotManager {
                     Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.WALL_HEIGHT + 1, sz),
                     classicPlotWorld.WALL_BLOCK.toPattern()
             );
-        }
-        queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 1, ez),
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.WALL_HEIGHT, ez),
-                classicPlotWorld.WALL_FILLING.toPattern()
-        );
-        if (classicPlotWorld.PLACE_TOP_BLOCK) {
             queue.setCuboid(
                     Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.WALL_HEIGHT + 1, ez),
                     Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.WALL_HEIGHT + 1, ez),
                     classicPlotWorld.WALL_BLOCK.toPattern()
             );
         }
-        queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 1, sz + 1),
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.ROAD_HEIGHT, ez - 1),
-                classicPlotWorld.ROAD_BLOCK.toPattern()
-        );
         return !enqueue || queue.enqueue();
     }
 
@@ -642,14 +638,19 @@ public class ClassicPlotManager extends SquarePlotManager {
 
         queue.setCuboid(
                 Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.ROAD_HEIGHT + 1, sz + 1),
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.getPlotManager().getWorldHeight(), ez - 1),
+                Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.getMaxGenHeight(), ez - 1),
                 BlockTypes.AIR.getDefaultState()
         );
-        queue.setCuboid(Location.at(classicPlotWorld.getWorldName(), sx + 1, 0, sz + 1),
+        if (classicPlotWorld.PLOT_BEDROCK) {
-                Location.at(classicPlotWorld.getWorldName(), ex - 1, 0, ez - 1), BlockUtil.get((short) 7, (byte) 0)
+            queue.setCuboid(
-        );
+                    Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight(), sz + 1),
+                    Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.getMinGenHeight(), ez - 1),
+                    BlockTypes.BEDROCK.getDefaultState()
+            );
+        }
+        int startYOffset = classicPlotWorld.PLOT_BEDROCK ? 1 : 0;
         queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 1, sz + 1),
+                Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight() + startYOffset, sz + 1),
                 Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.ROAD_HEIGHT, ez - 1),
                 classicPlotWorld.ROAD_BLOCK.toPattern()
         );
@@ -679,11 +680,12 @@ public class ClassicPlotManager extends SquarePlotManager {
                                 classicPlotWorld.schematicStartHeight() + 1,
                                 sz
                         ),
-                        Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getPlotManager().getWorldHeight(), ez),
+                        Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getMaxGenHeight(), ez),
                         BlockTypes.AIR.getDefaultState()
                 );
+        int startYOffset = classicPlotWorld.PLOT_BEDROCK ? 1 : 0;
         queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx, 1, sz + 1),
+                Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.getMinGenHeight() + startYOffset, sz + 1),
                 Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.PLOT_HEIGHT - 1, ez - 1),
                 classicPlotWorld.MAIN_BLOCK.toPattern()
         );
@@ -719,11 +721,12 @@ public class ClassicPlotManager extends SquarePlotManager {
                                 classicPlotWorld.schematicStartHeight() + 1,
                                 sz
                         ),
-                        Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getPlotManager().getWorldHeight(), ez),
+                        Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getMaxGenHeight(), ez),
                         BlockTypes.AIR.getDefaultState()
                 );
+        int startYOffset = classicPlotWorld.PLOT_BEDROCK ? 1 : 0;
         queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx + 1, 1, sz),
+                Location.at(classicPlotWorld.getWorldName(), sx + 1, classicPlotWorld.getMinGenHeight() + startYOffset, sz),
                 Location.at(classicPlotWorld.getWorldName(), ex - 1, classicPlotWorld.PLOT_HEIGHT - 1, ez),
                 classicPlotWorld.MAIN_BLOCK.toPattern()
         );
@@ -758,11 +761,12 @@ public class ClassicPlotManager extends SquarePlotManager {
                                 classicPlotWorld.schematicStartHeight() + 1,
                                 sz
                         ),
-                        Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getPlotManager().getWorldHeight(), ez),
+                        Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.getMaxGenHeight(), ez),
                         BlockTypes.AIR.getDefaultState()
                 );
+        int startYOffset = classicPlotWorld.PLOT_BEDROCK ? 1 : 0;
         queue.setCuboid(
-                Location.at(classicPlotWorld.getWorldName(), sx, 1, sz),
+                Location.at(classicPlotWorld.getWorldName(), sx, classicPlotWorld.getMinGenHeight() + startYOffset, sz),
                 Location.at(classicPlotWorld.getWorldName(), ex, classicPlotWorld.PLOT_HEIGHT - 1, ez),
                 classicPlotWorld.MAIN_BLOCK.toPattern()
         );

Core/src/main/java/com/plotsquared/core/generator/ClassicPlotWorld.java

@@ -127,16 +127,16 @@ public abstract class ClassicPlotWorld extends SquarePlotWorld {
     public void loadConfiguration(ConfigurationSection config) {
         super.loadConfiguration(config);
         this.PLOT_BEDROCK = config.getBoolean("plot.bedrock");
-        this.PLOT_HEIGHT = Math.min(255, config.getInt("plot.height"));
+        this.PLOT_HEIGHT = Math.min(getMaxGenHeight(), config.getInt("plot.height"));
         this.MAIN_BLOCK = new BlockBucket(config.getString("plot.filling"));
         this.TOP_BLOCK = new BlockBucket(config.getString("plot.floor"));
         this.WALL_BLOCK = new BlockBucket(config.getString("wall.block"));
-        this.ROAD_HEIGHT = Math.min(255, config.getInt("road.height"));
+        this.ROAD_HEIGHT = Math.min(getMaxGenHeight(), config.getInt("road.height"));
         this.ROAD_BLOCK = new BlockBucket(config.getString("road.block"));
         this.WALL_FILLING = new BlockBucket(config.getString("wall.filling"));
-        this.WALL_HEIGHT = Math.min(254, config.getInt("wall.height"));
-        this.CLAIMED_WALL_BLOCK = new BlockBucket(config.getString("wall.block_claimed"));
         this.PLACE_TOP_BLOCK = config.getBoolean("wall.place_top_block");
+        this.WALL_HEIGHT = Math.min(getMaxGenHeight() - (PLACE_TOP_BLOCK ? 1 : 0), config.getInt("wall.height"));
+        this.CLAIMED_WALL_BLOCK = new BlockBucket(config.getString("wall.block_claimed"));
     }
 
     int schematicStartHeight() {

Core/src/main/java/com/plotsquared/core/generator/HybridGen.java

@@ -91,7 +91,7 @@ public class HybridGen extends IndependentPlotGenerator {
         if (hybridPlotWorld.PLOT_BEDROCK) {
             for (short x = 0; x < 16; x++) {
                 for (short z = 0; z < 16; z++) {
-                    result.setBlock(x, 0, z, BlockTypes.BEDROCK.getDefaultState());
+                    result.setBlock(x, hybridPlotWorld.getMinGenHeight(), z, BlockTypes.BEDROCK.getDefaultState());
                 }
             }
         }
@@ -156,7 +156,7 @@ public class HybridGen extends IndependentPlotGenerator {
             }
         }
         // generation
-        int startY = hybridPlotWorld.PLOT_BEDROCK ? 1 : 0;
+        int startY = hybridPlotWorld.getMinGenHeight() + (hybridPlotWorld.PLOT_BEDROCK ? 1: 0);
         for (short x = 0; x < 16; x++) {
             if (insideRoadX[x]) {
                 for (short z = 0; z < 16; z++) {

Core/src/main/java/com/plotsquared/core/generator/HybridPlotManager.java

@@ -46,7 +46,6 @@ import com.sk89q.worldedit.function.pattern.Pattern;
 import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BaseBlock;
-import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockTypes;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -107,22 +106,32 @@ public class HybridPlotManager extends ClassicPlotManager {
 
     @Override
     public boolean createRoadEast(final @NonNull Plot plot, @Nullable QueueCoordinator queue) {
+        boolean enqueue = false;
+        if (queue == null) {
+            queue = hybridPlotWorld.getQueue();
+            enqueue = true;
+        }
         super.createRoadEast(plot, queue);
         PlotId id = plot.getId();
         PlotId id2 = PlotId.of(id.getX() + 1, id.getY());
         Location bot = getPlotBottomLocAbs(id2);
         Location top = getPlotTopLocAbs(id);
-        Location pos1 = Location.at(hybridPlotWorld.getWorldName(), top.getX() + 1, 0, bot.getZ() - 1);
+        Location pos1 = Location.at(
-        Location pos2 = Location.at(hybridPlotWorld.getWorldName(), bot.getX(), Math.min(getWorldHeight(), 255), top.getZ() + 1);
+                hybridPlotWorld.getWorldName(),
+                top.getX() + 1,
+                hybridPlotWorld.getMinGenHeight(),
+                bot.getZ() - 1
+        );
+        Location pos2 = Location.at(
+                hybridPlotWorld.getWorldName(),
+                bot.getX(),
+                hybridPlotWorld.getMaxGenHeight(),
+                top.getZ() + 1
+        );
         this.resetBiome(hybridPlotWorld, pos1, pos2);
         if (!hybridPlotWorld.ROAD_SCHEMATIC_ENABLED) {
             return true;
         }
-        boolean enqueue = false;
-        if (queue == null) {
-            queue = hybridPlotWorld.getQueue();
-            enqueue = true;
-        }
         createSchemAbs(queue, pos1, pos2, true);
         return !enqueue || queue.enqueue();
     }
@@ -139,7 +148,7 @@ public class HybridPlotManager extends ClassicPlotManager {
                         (pos1.getX() + pos2.getX()) / 2,
                         (pos1.getZ() + pos2.getZ()) / 2
                 ), biome)) {
-            WorldUtil.setBiome(hybridPlotWorld.getWorldName(), pos1.getX(), pos1.getZ(), pos2.getX(), pos2.getZ(), biome);
+            WorldUtil.setBiome(hybridPlotWorld.getWorldName(), new CuboidRegion(pos1.getBlockVector3(), pos2.getBlockVector3()), biome);
         }
     }
 
@@ -190,38 +199,38 @@ public class HybridPlotManager extends ClassicPlotManager {
 
     @Override
     public boolean createRoadSouth(final @NonNull Plot plot, @Nullable QueueCoordinator queue) {
+        boolean enqueue = false;
+        if (queue == null) {
+            enqueue = true;
+            queue = hybridPlotWorld.getQueue();
+        }
         super.createRoadSouth(plot, queue);
         PlotId id = plot.getId();
         PlotId id2 = PlotId.of(id.getX(), id.getY() + 1);
         Location bot = getPlotBottomLocAbs(id2);
         Location top = getPlotTopLocAbs(id);
-        Location pos1 = Location.at(hybridPlotWorld.getWorldName(), bot.getX() - 1, 0, top.getZ() + 1);
+        Location pos1 = Location.at(hybridPlotWorld.getWorldName(), bot.getX() - 1, hybridPlotWorld.getMinGenHeight(), top.getZ() + 1);
-        Location pos2 = Location.at(hybridPlotWorld.getWorldName(), top.getX() + 1, Math.min(getWorldHeight(), 255), bot.getZ());
+        Location pos2 = Location.at(hybridPlotWorld.getWorldName(), top.getX() + 1, hybridPlotWorld.getMaxGenHeight(), bot.getZ());
         this.resetBiome(hybridPlotWorld, pos1, pos2);
         if (!hybridPlotWorld.ROAD_SCHEMATIC_ENABLED) {
             return true;
         }
-        boolean enqueue = false;
-        if (queue == null) {
-            enqueue = true;
-            queue = hybridPlotWorld.getQueue();
-        }
         createSchemAbs(queue, pos1, pos2, true);
         return !enqueue || queue.enqueue();
     }
 
     @Override
     public boolean createRoadSouthEast(final @NonNull Plot plot, @Nullable QueueCoordinator queue) {
-        super.createRoadSouthEast(plot, queue);
-        PlotId id = plot.getId();
-        PlotId id2 = PlotId.of(id.getX() + 1, id.getY() + 1);
-        Location pos1 = getPlotTopLocAbs(id).add(1, 0, 1).withY(0);
-        Location pos2 = getPlotBottomLocAbs(id2).withY(Math.min(getWorldHeight(), 255));
         boolean enqueue = false;
         if (queue == null) {
             enqueue = true;
             queue = hybridPlotWorld.getQueue();
         }
+        super.createRoadSouthEast(plot, queue);
+        PlotId id = plot.getId();
+        PlotId id2 = PlotId.of(id.getX() + 1, id.getY() + 1);
+        Location pos1 = getPlotTopLocAbs(id).add(1, 0, 1);
+        Location pos2 = getPlotBottomLocAbs(id2);
         createSchemAbs(queue, pos1, pos2, true);
         if (hybridPlotWorld.ROAD_SCHEMATIC_ENABLED) {
             createSchemAbs(queue, pos1, pos2, true);
@@ -271,11 +280,23 @@ public class HybridPlotManager extends ClassicPlotManager {
             queue.setCompleteTask(whenDone);
         }
         if (!canRegen) {
-            queue.setCuboid(pos1.withY(0), pos2.withY(0), bedrock);
+            queue.setCuboid(
+                    pos1.withY(hybridPlotWorld.getMinGenHeight()),
+                    pos2.withY(hybridPlotWorld.getMinGenHeight()),
+                    hybridPlotWorld.PLOT_BEDROCK ? bedrock : filling
+            );
             // Each component has a different layer
-            queue.setCuboid(pos1.withY(1), pos2.withY(hybridPlotWorld.PLOT_HEIGHT - 1), filling);
+            queue.setCuboid(
+                    pos1.withY(hybridPlotWorld.getMinGenHeight() + 1),
+                    pos2.withY(hybridPlotWorld.PLOT_HEIGHT - 1),
+                    filling
+            );
             queue.setCuboid(pos1.withY(hybridPlotWorld.PLOT_HEIGHT), pos2.withY(hybridPlotWorld.PLOT_HEIGHT), plotfloor);
-            queue.setCuboid(pos1.withY(hybridPlotWorld.PLOT_HEIGHT + 1), pos2.withY(getWorldHeight()), BlockTypes.AIR.getDefaultState());
+            queue.setCuboid(
+                    pos1.withY(hybridPlotWorld.PLOT_HEIGHT + 1),
+                    pos2.withY(hybridPlotWorld.getMaxGenHeight()),
+                    BlockTypes.AIR.getDefaultState()
+            );
             queue.setBiomeCuboid(pos1, pos2, biome);
         } else {
             queue.setRegenRegion(new CuboidRegion(pos1.getBlockVector3(), pos2.getBlockVector3()));

Core/src/main/java/com/plotsquared/core/generator/HybridPlotWorld.java

@@ -79,6 +79,7 @@ public class HybridPlotWorld extends ClassicPlotWorld {
     public int SCHEM_Y;
     private Location SIGN_LOCATION;
     private File root = null;
+    private int lastOverlayHeightError = Integer.MIN_VALUE;
 
     @Inject
     private SchematicHandler schematicHandler;
@@ -171,9 +172,9 @@ public class HybridPlotWorld extends ClassicPlotWorld {
     public void loadConfiguration(ConfigurationSection config) {
         super.loadConfiguration(config);
         if ((this.ROAD_WIDTH & 1) == 0) {
-            this.PATH_WIDTH_LOWER = (short) (Math.floor(this.ROAD_WIDTH / 2) - 1);
+            this.PATH_WIDTH_LOWER = (short) (Math.floor(this.ROAD_WIDTH / 2f) - 1);
         } else {
-            this.PATH_WIDTH_LOWER = (short) Math.floor(this.ROAD_WIDTH / 2);
+            this.PATH_WIDTH_LOWER = (short) Math.floor(this.ROAD_WIDTH / 2f);
         }
         if (this.ROAD_WIDTH == 0) {
             this.PATH_WIDTH_UPPER = (short) (this.SIZE + 1);
@@ -251,31 +252,34 @@ public class HybridPlotWorld extends ClassicPlotWorld {
         Schematic schematic2 = this.schematicHandler.getSchematic(schematic2File);
         Schematic schematic3 = this.schematicHandler.getSchematic(schematic3File);
         int shift = this.ROAD_WIDTH / 2;
-        int oddshift = (this.ROAD_WIDTH & 1) == 0 ? 0 : 1;
+        int oddshift = (this.ROAD_WIDTH & 1);
 
         SCHEM_Y = schematicStartHeight();
         int plotY = PLOT_HEIGHT - SCHEM_Y;
         int minRoadWall = Settings.Schematics.USE_WALL_IN_ROAD_SCHEM_HEIGHT ? Math.min(ROAD_HEIGHT, WALL_HEIGHT) : ROAD_HEIGHT;
         int roadY = minRoadWall - SCHEM_Y;
 
+        int worldHeight = getMaxGenHeight() - getMinGenHeight() + 1;
+
+        // SCHEM_Y should be normalised to the plot "start" height
         if (schematic3 != null) {
-            if (schematic3.getClipboard().getDimensions().getY() == 256) {
+            if (schematic3.getClipboard().getDimensions().getY() == worldHeight) {
                 SCHEM_Y = plotY = 0;
             } else if (!Settings.Schematics.PASTE_ON_TOP) {
-                SCHEM_Y = plotY = getMinBuildHeight();
+                SCHEM_Y = plotY = getMinBuildHeight() - getMinGenHeight();
             }
         }
 
         if (schematic1 != null) {
-            if (schematic1.getClipboard().getDimensions().getY() == 256) {
+            if (schematic1.getClipboard().getDimensions().getY() == worldHeight) {
-                SCHEM_Y = roadY = 0;
+                SCHEM_Y = roadY = getMinGenHeight();
-                if (schematic3 != null && schematic3.getClipboard().getDimensions().getY() != 256
+                if (schematic3 != null && schematic3.getClipboard().getDimensions().getY() != worldHeight
                         && !Settings.Schematics.PASTE_ON_TOP) {
                     plotY = PLOT_HEIGHT;
                 }
             } else if (!Settings.Schematics.PASTE_ROAD_ON_TOP) {
                 SCHEM_Y = roadY = getMinBuildHeight();
-                if (schematic3 != null && schematic3.getClipboard().getDimensions().getY() != 256
+                if (schematic3 != null && schematic3.getClipboard().getDimensions().getY() != worldHeight
                         && !Settings.Schematics.PASTE_ON_TOP) {
                     plotY = PLOT_HEIGHT;
                 }
@@ -428,7 +432,10 @@ public class HybridPlotWorld extends ClassicPlotWorld {
         int pair = MathMan.pair(x, z);
         BaseBlock[] existing = this.G_SCH.computeIfAbsent(pair, k -> new BaseBlock[height]);
         if (y >= height) {
-            LOGGER.error("Error adding overlay block. `y > height`");
+            if (y != lastOverlayHeightError) {
+                lastOverlayHeightError = y;
+                LOGGER.error(String.format("Error adding overlay block. `y > height`. y=%s, height=%s", y, height));
+            }
             return;
         }
         existing[y] = id;

Core/src/main/java/com/plotsquared/core/generator/HybridUtils.java

@@ -65,6 +65,7 @@ import com.sk89q.worldedit.world.block.BlockTypes;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.File;
 import java.util.ArrayDeque;
@@ -73,6 +74,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -85,7 +87,9 @@ public class HybridUtils {
     public static HybridUtils manager;
     public static Set<BlockVector2> regions;
     public static int height;
-    public static Set<BlockVector2> chunks = new HashSet<>();
+    // Use ordered for reasonable chunk loading order to reduce paper unloading neighbour chunks and then us attempting to load
+    // them again, causing errors
+    public static Set<BlockVector2> chunks = new LinkedHashSet<>();
     public static PlotArea area;
     public static boolean UPDATE = false;
 
@@ -145,6 +149,8 @@ public class HybridUtils {
             final int ctz = tz >> 4;
             final int width = tx - bx + 1;
             final int length = tz - bz + 1;
+            final int height = area.getMaxGenHeight() - area.getMinGenHeight() + 1;
+            final int minHeight = area.getMinGenHeight();
 
             final PlotArea area = this.plotAreaManager.getPlotArea(world, null);
 
@@ -157,7 +163,7 @@ public class HybridUtils {
 
             final BlockState airBlock = BlockTypes.AIR.getDefaultState();
             final BlockState[][][] oldBlocks = chunk.getBlocks();
-            final BlockState[][][] newBlocks = new BlockState[256][width][length];
+            final BlockState[][][] newBlocks = new BlockState[height][width][length];
             for (final BlockState[][] newBlock : newBlocks) {
                 for (final BlockState[] blockStates : newBlock) {
                     Arrays.fill(blockStates, airBlock);
@@ -211,11 +217,12 @@ public class HybridUtils {
                     int xx = chunkBlockX + x;
                     for (int z = minZ; z <= maxZ; z++) {
                         int zz = chunkBlockZ + z;
-                        for (int y = 0; y < 256; y++) {
+                        for (int yIndex = 0; yIndex < height; yIndex++) {
+                            int y = yIndex + minHeight;
                             BlockState block = queue.getBlock(xx, y, zz);
                             int xr = xb + x;
                             int zr = zb + z;
-                            newBlocks[y][xr][zr] = block;
+                            newBlocks[yIndex][xr][zr] = block;
                         }
                     }
                 }
@@ -232,10 +239,10 @@ public class HybridUtils {
                 for (int x = 0; x < width; x++) {
                     for (int z = 0; z < length; z++) {
                         Set<BlockType> types = new HashSet<>();
-                        for (int y = 0; y < 256; y++) {
+                        for (int yIndex = 0; yIndex < height; yIndex++) {
-                            BlockState old = oldBlocks[y][x][z];
+                            BlockState old = oldBlocks[yIndex][x][z];
                             try {
-                                BlockState now = newBlocks[y][x][z];
+                                BlockState now = newBlocks[yIndex][x][z];
                                 if (!old.equals(now)) {
                                     changes[i]++;
                                 }
@@ -244,23 +251,23 @@ public class HybridUtils {
                                 } else {
                                     // check vertices
                                     // modifications_adjacent
-                                    if (x > 0 && z > 0 && y > 0 && x < width - 1 && z < length - 1 && y < 255) {
+                                    if (x > 0 && z > 0 && yIndex > 0 && x < width - 1 && z < length - 1 && yIndex < (height - 1)) {
-                                        if (newBlocks[y - 1][x][z].getBlockType().getMaterial().isAir()) {
+                                        if (newBlocks[yIndex - 1][x][z].getBlockType().getMaterial().isAir()) {
                                             faces[i]++;
                                         }
-                                        if (newBlocks[y][x - 1][z].getBlockType().getMaterial().isAir()) {
+                                        if (newBlocks[yIndex][x - 1][z].getBlockType().getMaterial().isAir()) {
                                             faces[i]++;
                                         }
-                                        if (newBlocks[y][x][z - 1].getBlockType().getMaterial().isAir()) {
+                                        if (newBlocks[yIndex][x][z - 1].getBlockType().getMaterial().isAir()) {
                                             faces[i]++;
                                         }
-                                        if (newBlocks[y + 1][x][z].getBlockType().getMaterial().isAir()) {
+                                        if (newBlocks[yIndex + 1][x][z].getBlockType().getMaterial().isAir()) {
                                             faces[i]++;
                                         }
-                                        if (newBlocks[y][x + 1][z].getBlockType().getMaterial().isAir()) {
+                                        if (newBlocks[yIndex][x + 1][z].getBlockType().getMaterial().isAir()) {
                                             faces[i]++;
                                         }
-                                        if (newBlocks[y][x][z + 1].getBlockType().getMaterial().isAir()) {
+                                        if (newBlocks[yIndex][x][z + 1].getBlockType().getMaterial().isAir()) {
                                             faces[i]++;
                                         }
                                     }
@@ -408,7 +415,7 @@ public class HybridUtils {
         }
         HybridUtils.UPDATE = true;
         Set<BlockVector2> regions = this.worldUtil.getChunkChunks(area.getWorldName());
-        return scheduleRoadUpdate(area, regions, extend, new HashSet<>());
+        return scheduleRoadUpdate(area, regions, extend, new LinkedHashSet<>());
     }
 
     public boolean scheduleSingleRegionRoadUpdate(Plot plot, int extend) {
@@ -418,7 +425,7 @@ public class HybridUtils {
         HybridUtils.UPDATE = true;
         Set<BlockVector2> regions = new HashSet<>();
         regions.add(RegionManager.getRegion(plot.getCenterSynchronous()));
-        return scheduleRoadUpdate(plot.getArea(), regions, extend, new HashSet<>());
+        return scheduleRoadUpdate(plot.getArea(), regions, extend, new LinkedHashSet<>());
     }
 
     public boolean scheduleRoadUpdate(
@@ -431,26 +438,29 @@ public class HybridUtils {
         HybridUtils.area = area;
         HybridUtils.height = extend;
         HybridUtils.chunks = chunks;
+        final int initial = 1024 * regions.size() + chunks.size();
         final AtomicInteger count = new AtomicInteger(0);
         TaskManager.runTask(new Runnable() {
             @Override
             public void run() {
                 if (!UPDATE) {
                     Iterator<BlockVector2> iter = chunks.iterator();
+                    QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
                     while (iter.hasNext()) {
                         BlockVector2 chunk = iter.next();
                         iter.remove();
-                        boolean regenedRoad = regenerateRoad(area, chunk, extend);
+                        boolean regenedRoad = regenerateRoad(area, chunk, extend, queue);
                         if (!regenedRoad) {
-                            LOGGER.info("Failed to regenerate roads");
+                            LOGGER.info("Failed to regenerate roads in chunk {}", chunk);
                         }
                     }
+                    queue.enqueue();
                     LOGGER.info("Cancelled road task");
                     return;
                 }
                 count.incrementAndGet();
-                if (count.intValue() % 20 == 0) {
+                if (count.intValue() % 10 == 0) {
-                    LOGGER.info("Progress: {}%", 100 * (2048 - chunks.size()) / 2048);
+                    LOGGER.info("Progress: {}%", 100 * (initial - (chunks.size() + 1024 * regions.size())) / initial);
                 }
                 if (HybridUtils.regions.isEmpty() && chunks.isEmpty()) {
                     regeneratePlotWalls(area);
@@ -462,7 +472,7 @@ public class HybridUtils {
                     final Runnable task = this;
                     TaskManager.runTaskAsync(() -> {
                         try {
-                            if (chunks.size() < 1024) {
+                            if (chunks.size() < 64) {
                                 if (!HybridUtils.regions.isEmpty()) {
                                     Iterator<BlockVector2> iterator = HybridUtils.regions.iterator();
                                     BlockVector2 loc = iterator.next();
@@ -475,18 +485,35 @@ public class HybridUtils {
                             }
                             if (!chunks.isEmpty()) {
                                 TaskManager.getPlatformImplementation().sync(() -> {
-                                    long start = System.currentTimeMillis();
                                     Iterator<BlockVector2> iterator = chunks.iterator();
-                                    while (System.currentTimeMillis() - start < 20 && !chunks.isEmpty()) {
+                                    if (chunks.size() >= 32) {
+                                        QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
+                                        for (int i = 0; i < 32; i++) {
+                                            final BlockVector2 chunk = iterator.next();
+                                            iterator.remove();
+                                            boolean regenedRoads = regenerateRoad(area, chunk, extend, queue);
+                                            if (!regenedRoads) {
+                                                LOGGER.info("Failed to regenerate the road in chunk {}", chunk);
+                                            }
+                                        }
+                                        queue.setCompleteTask(task);
+                                        queue.enqueue();
+                                        return null;
+                                    }
+                                    QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
+                                    while (!chunks.isEmpty()) {
                                         final BlockVector2 chunk = iterator.next();
                                         iterator.remove();
-                                        boolean regenedRoads = regenerateRoad(area, chunk, extend);
+                                        boolean regenedRoads = regenerateRoad(area, chunk, extend, queue);
                                         if (!regenedRoads) {
-                                            LOGGER.info("Failed to regenerate road");
+                                            LOGGER.info("Failed to regenerate road in chunk {}", chunk);
                                         }
                                     }
+                                    queue.setCompleteTask(task);
+                                    queue.enqueue();
                                     return null;
                                 });
+                                return;
                             }
                         } catch (Exception e) {
                             e.printStackTrace();
@@ -514,7 +541,6 @@ public class HybridUtils {
         Location bot = plot.getBottomAbs().subtract(1, 0, 1);
         Location top = plot.getTopAbs();
         final HybridPlotWorld plotworld = (HybridPlotWorld) plot.getArea();
-        PlotManager plotManager = plotworld.getPlotManager();
         // Do not use plotworld#schematicStartHeight() here as we want to restore the pre 6.1.4 way of doing it if
         //  USE_WALL_IN_ROAD_SCHEM_HEIGHT is false
         int schemY = Settings.Schematics.USE_WALL_IN_ROAD_SCHEM_HEIGHT ?
@@ -524,10 +550,10 @@ public class HybridUtils {
         int sy = Settings.Schematics.PASTE_ROAD_ON_TOP ? schemY : plot.getArea().getMinBuildHeight();
         int ex = bot.getX();
         int ez = top.getZ();
-        int ey = get_ey(plotManager, queue, sx, ex, sz, ez, sy);
+        int ey = get_ey(plotworld, queue, sx, ex, sz, ez, sy);
         int bz = sz - plotworld.ROAD_WIDTH;
         int tz = sz - 1;
-        int ty = get_ey(plotManager, queue, sx, ex, bz, tz, sy);
+        int ty = get_ey(plotworld, queue, sx, ex, bz, tz, sy);
 
         final Set<CuboidRegion> sideRoad = Collections.singleton(RegionUtil.createRegion(sx, ex, sy, ey, sz, ez));
         final Set<CuboidRegion> intersection = Collections.singleton(RegionUtil.createRegion(sx, ex, sy, ty, bz, tz));
@@ -553,11 +579,11 @@ public class HybridUtils {
         return true;
     }
 
-    public int get_ey(final PlotManager pm, QueueCoordinator queue, int sx, int ex, int sz, int ez, int sy) {
+    private int get_ey(final HybridPlotWorld hpw, QueueCoordinator queue, int sx, int ex, int sz, int ez, int sy) {
         int ey = sy;
         for (int x = sx; x <= ex; x++) {
             for (int z = sz; z <= ez; z++) {
-                for (int y = sy; y <= pm.getWorldHeight(); y++) {
+                for (int y = sy; y <= hpw.getMaxGenHeight(); y++) {
                     if (y > ey) {
                         BlockState block = queue.getBlock(x, y, z);
                         if (!block.getBlockType().getMaterial().isAir()) {
@@ -570,7 +596,36 @@ public class HybridUtils {
         return ey;
     }
 
+    /**
+     * Regenerate the road in a chunk in a plot area.
+     *
+     * @param area   Plot area to regenerate road for
+     * @param chunk  Chunk location to regenerate
+     * @param extend How far to extend setting air above the road
+     * @return if successful
+     * @deprecated use {@link HybridUtils#regenerateRoad(PlotArea, BlockVector2, int, QueueCoordinator)}
+     */
+    @Deprecated(forRemoval = true, since = "TODO")
     public boolean regenerateRoad(final PlotArea area, final BlockVector2 chunk, int extend) {
+        return regenerateRoad(area, chunk, extend, null);
+    }
+
+    /**
+     * Regenerate the road in a chunk in a plot area.
+     *
+     * @param area             Plot area to regenerate road for
+     * @param chunk            Chunk location to regenerate
+     * @param extend           How far to extend setting air above the road
+     * @param queueCoordinator {@link QueueCoordinator} to use to set the blocks. Null if one should be created and enqueued
+     * @return if successful
+     * @since TODO
+     */
+    public boolean regenerateRoad(
+            final PlotArea area,
+            final BlockVector2 chunk,
+            int extend,
+            @Nullable QueueCoordinator queueCoordinator
+    ) {
         int x = chunk.getX() << 4;
         int z = chunk.getZ() << 4;
         int ex = x + 15;
@@ -596,92 +651,100 @@ public class HybridUtils {
         z -= plotWorld.ROAD_OFFSET_Z;
         final int finalX = x;
         final int finalZ = z;
-        QueueCoordinator queue = this.blockQueue.getNewQueue(worldUtil.getWeWorld(plotWorld.getWorldName()));
+        final boolean enqueue;
+        final QueueCoordinator queue;
+        if (queueCoordinator == null) {
+            queue = this.blockQueue.getNewQueue(worldUtil.getWeWorld(plotWorld.getWorldName()));
+            enqueue = true;
+        } else {
+            queue = queueCoordinator;
+            enqueue = false;
+        }
         if (id1 == null || id2 == null || id1 != id2) {
-            this.chunkManager.loadChunk(area.getWorldName(), chunk, false).thenRun(() -> {
+            if (id1 != null) {
-                if (id1 != null) {
+                Plot p1 = area.getPlotAbs(id1);
-                    Plot p1 = area.getPlotAbs(id1);
+                if (p1 != null && p1.hasOwner() && p1.isMerged()) {
-                    if (p1 != null && p1.hasOwner() && p1.isMerged()) {
+                    toCheck.set(true);
-                        toCheck.set(true);
-                    }
                 }
-                if (id2 != null && !toCheck.get()) {
+            }
-                    Plot p2 = area.getPlotAbs(id2);
+            if (id2 != null && !toCheck.get()) {
-                    if (p2 != null && p2.hasOwner() && p2.isMerged()) {
+                Plot p2 = area.getPlotAbs(id2);
-                        toCheck.set(true);
+                if (p2 != null && p2.hasOwner() && p2.isMerged()) {
-                    }
+                    toCheck.set(true);
                 }
-                int size = plotWorld.SIZE;
+            }
-                for (int X = 0; X < 16; X++) {
+            short size = plotWorld.SIZE;
-                    short absX = (short) ((finalX + X) % size);
+            for (int X = 0; X < 16; X++) {
-                    for (int Z = 0; Z < 16; Z++) {
+                short absX = (short) ((finalX + X) % size);
-                        short absZ = (short) ((finalZ + Z) % size);
+                for (int Z = 0; Z < 16; Z++) {
-                        if (absX < 0) {
+                    short absZ = (short) ((finalZ + Z) % size);
-                            absX += size;
+                    if (absX < 0) {
-                        }
+                        absX += size;
-                        if (absZ < 0) {
+                    }
-                            absZ += size;
+                    if (absZ < 0) {
-                        }
+                        absZ += size;
-                        boolean condition;
+                    }
-                        if (toCheck.get()) {
+                    boolean condition;
-                            condition = manager.getPlotId(
+                    if (toCheck.get()) {
-                                    finalX + X + plotWorld.ROAD_OFFSET_X,
+                        condition = manager.getPlotId(
-                                    1,
+                                finalX + X + plotWorld.ROAD_OFFSET_X,
-                                    finalZ + Z + plotWorld.ROAD_OFFSET_Z
+                                1,
-                            ) == null;
+                                finalZ + Z + plotWorld.ROAD_OFFSET_Z
-                        } else {
+                        ) == null;
-                            boolean gx = absX > plotWorld.PATH_WIDTH_LOWER;
+                    } else {
-                            boolean gz = absZ > plotWorld.PATH_WIDTH_LOWER;
+                        boolean gx = absX > plotWorld.PATH_WIDTH_LOWER;
-                            boolean lx = absX < plotWorld.PATH_WIDTH_UPPER;
+                        boolean gz = absZ > plotWorld.PATH_WIDTH_LOWER;
-                            boolean lz = absZ < plotWorld.PATH_WIDTH_UPPER;
+                        boolean lx = absX < plotWorld.PATH_WIDTH_UPPER;
-                            condition = !gx || !gz || !lx || !lz;
+                        boolean lz = absZ < plotWorld.PATH_WIDTH_UPPER;
-                        }
+                        condition = !gx || !gz || !lx || !lz;
-                        if (condition) {
+                    }
-                            BaseBlock[] blocks = plotWorld.G_SCH.get(MathMan.pair(absX, absZ));
+                    if (condition) {
-                            int minY = Settings.Schematics.PASTE_ROAD_ON_TOP ? plotWorld.SCHEM_Y : 1;
+                        BaseBlock[] blocks = plotWorld.G_SCH.get(MathMan.pair(absX, absZ));
-                            int maxY = Math.max(extend, blocks.length);
+                        int minY = Settings.Schematics.PASTE_ROAD_ON_TOP ? plotWorld.SCHEM_Y : area.getMinGenHeight() + 1;
-                            for (int y = 0; y < maxY; y++) {
+                        int maxDy = Math.max(extend, blocks.length);
-                                if (y > blocks.length - 1) {
+                        for (int dy = 0; dy < maxDy; dy++) {
+                            if (dy > blocks.length - 1) {
+                                queue.setBlock(
+                                        finalX + X + plotWorld.ROAD_OFFSET_X,
+                                        minY + dy,
+                                        finalZ + Z + plotWorld.ROAD_OFFSET_Z,
+                                        WEExtent.AIRBASE
+                                );
+                            } else {
+                                BaseBlock block = blocks[dy];
+                                if (block != null) {
                                     queue.setBlock(
                                             finalX + X + plotWorld.ROAD_OFFSET_X,
-                                            minY + y,
+                                            minY + dy,
+                                            finalZ + Z + plotWorld.ROAD_OFFSET_Z,
+                                            block
+                                    );
+                                } else {
+                                    queue.setBlock(
+                                            finalX + X + plotWorld.ROAD_OFFSET_X,
+                                            minY + dy,
                                             finalZ + Z + plotWorld.ROAD_OFFSET_Z,
                                             WEExtent.AIRBASE
                                     );
-                                } else {
-                                    BaseBlock block = blocks[y];
-                                    if (block != null) {
-                                        queue.setBlock(
-                                                finalX + X + plotWorld.ROAD_OFFSET_X,
-                                                minY + y,
-                                                finalZ + Z + plotWorld.ROAD_OFFSET_Z,
-                                                block
-                                        );
-                                    } else {
-                                        queue.setBlock(
-                                                finalX + X + plotWorld.ROAD_OFFSET_X,
-                                                minY + y,
-                                                finalZ + Z + plotWorld.ROAD_OFFSET_Z,
-                                                WEExtent.AIRBASE
-                                        );
-                                    }
                                 }
                             }
-                            BiomeType biome = plotWorld.G_SCH_B.get(MathMan.pair(absX, absZ));
+                        }
-                            if (biome != null) {
+                        BiomeType biome = plotWorld.G_SCH_B.get(MathMan.pair(absX, absZ));
-                                queue.setBiome(finalX + X + plotWorld.ROAD_OFFSET_X, finalZ + Z + plotWorld.ROAD_OFFSET_Z, biome);
+                        if (biome != null) {
-                            } else {
+                            queue.setBiome(finalX + X + plotWorld.ROAD_OFFSET_X, finalZ + Z + plotWorld.ROAD_OFFSET_Z, biome);
-                                queue.setBiome(
+                        } else {
-                                        finalX + X + plotWorld.ROAD_OFFSET_X,
+                            queue.setBiome(
-                                        finalZ + Z + plotWorld.ROAD_OFFSET_Z,
+                                    finalX + X + plotWorld.ROAD_OFFSET_X,
-                                        plotWorld.getPlotBiome()
+                                    finalZ + Z + plotWorld.ROAD_OFFSET_Z,
-                                );
+                                    plotWorld.getPlotBiome()
-                            }
+                            );
                         }
                     }
                 }
+            }
+            if (enqueue) {
                 queue.enqueue();
-            });
+            }
             return true;
         }
         return false;

Core/src/main/java/com/plotsquared/core/generator/SquarePlotManager.java

@@ -96,7 +96,7 @@ public abstract class SquarePlotManager extends GridPlotManager {
                 .floor(squarePlotWorld.ROAD_WIDTH / 2) - 1;
         int z = (squarePlotWorld.ROAD_OFFSET_Z + (pz * (squarePlotWorld.ROAD_WIDTH + squarePlotWorld.PLOT_WIDTH))) - (int) Math
                 .floor(squarePlotWorld.ROAD_WIDTH / 2) - 1;
-        return Location.at(squarePlotWorld.getWorldName(), x, Math.min(getWorldHeight(), 255), z);
+        return Location.at(squarePlotWorld.getWorldName(), x, squarePlotWorld.getMaxGenHeight(), z);
     }
 
     @Override
@@ -260,7 +260,7 @@ public abstract class SquarePlotManager extends GridPlotManager {
                 - (int) Math.floor(squarePlotWorld.ROAD_WIDTH / 2);
         int z = (squarePlotWorld.ROAD_OFFSET_Z + (pz * (squarePlotWorld.ROAD_WIDTH + squarePlotWorld.PLOT_WIDTH))) - squarePlotWorld.PLOT_WIDTH
                 - (int) Math.floor(squarePlotWorld.ROAD_WIDTH / 2);
-        return Location.at(squarePlotWorld.getWorldName(), x, squarePlotWorld.getMinBuildHeight(), z);
+        return Location.at(squarePlotWorld.getWorldName(), x, squarePlotWorld.getMinGenHeight(), z);
     }
 
 }

Core/src/main/java/com/plotsquared/core/location/World.java

@@ -58,6 +58,21 @@ public interface World<T> {
      */
     @NonNull String getName();
 
+    /**
+     * Get the min world height. Inclusive.
+     *
+     * @since TODO
+     */
+    int getMinHeight();
+
+
+    /**
+     * Get the max world height. Inclusive.
+     *
+     * @since TODO
+     */
+    int getMaxHeight();
+
     class NullWorld<T> implements World<T> {
 
         private NullWorld() {
@@ -74,6 +89,16 @@ public interface World<T> {
             return "";
         }
 
+        @Override
+        public int getMinHeight() {
+            return 0;
+        }
+
+        @Override
+        public int getMaxHeight() {
+            return 0;
+        }
+
         @Override
         public boolean equals(final Object obj) {
             return obj instanceof NullWorld;

Core/src/main/java/com/plotsquared/core/plot/Plot.java

@@ -122,7 +122,7 @@ import static com.plotsquared.core.util.entity.EntityCategories.CAP_VEHICLE;
  */
 public class Plot {
 
-
+    @Deprecated(forRemoval = true, since = "TODO")
     public static final int MAX_HEIGHT = 256;
 
     private static final Logger LOGGER = LogManager.getLogger("PlotSquared/" + Plot.class.getSimpleName());
@@ -1371,7 +1371,7 @@ public class Plot {
         int z = largest.getMinimumPoint().getZ() - 1;
         PlotManager manager = getManager();
         int y = isLoaded() ? this.worldUtil.getHighestBlockSynchronous(getWorldName(), x, z) : 62;
-        if (area.allowSigns() && (y <= 0 || y >= 255)) {
+        if (area.allowSigns() && (y <= area.getMinGenHeight() || y >= area.getMaxGenHeight())) {
             y = Math.max(y, manager.getSignLoc(this).getY() - 1);
         }
         return Location.at(getWorldName(), x, y + 1, z);
@@ -1387,7 +1387,7 @@ public class Plot {
         if (isLoaded()) {
             this.worldUtil.getHighestBlock(getWorldName(), x, z, y -> {
                 int height = y;
-                if (area.allowSigns() && (y <= 0 || y >= 255)) {
+                if (area.allowSigns() && (y <= area.getMinGenHeight() || y >= area.getMaxGenHeight())) {
                     height = Math.max(y, manager.getSignLoc(this).getY() - 1);
                 }
                 result.accept(Location.at(getWorldName(), x, height + 1, z));
@@ -1619,8 +1619,8 @@ public class Plot {
     public double getVolume() {
         double count = 0;
         for (CuboidRegion region : getRegions()) {
-            count += (region.getMaximumPoint().getX() - (double) region.getMinimumPoint().getX() + 1) * (
+            // CuboidRegion#getArea is deprecated and we want to ensure use of correct height
-                    region.getMaximumPoint().getZ() - (double) region.getMinimumPoint().getZ() + 1) * MAX_HEIGHT;
+            count += region.getLength() * region.getWidth() * (area.getMaxGenHeight() - area.getMinGenHeight() + 1);
         }
         return count;
     }
@@ -1738,7 +1738,6 @@ public class Plot {
             area.addPlot(this);
             updateWorldBorder();
         }
-        this.getPlotModificationManager().setSign(player.getName());
         player.sendMessage(TranslatableCaption.of("working.claimed"), Template.of("plot", this.getId().toString()));
         if (teleport) {
             if (!auto && Settings.Teleport.ON_CLAIM) {
@@ -1786,6 +1785,7 @@ public class Plot {
             );
         }
         plotworld.getPlotManager().claimPlot(this, null);
+        this.getPlotModificationManager().setSign(player.getName());
         return true;
     }
 
@@ -2438,8 +2438,8 @@ public class Plot {
             return regions_cache;
         }
         if (!this.isMerged()) {
-            Location pos1 = this.getBottomAbs();
+            Location pos1 = this.getBottomAbs().withY(getArea().getMinBuildHeight());
-            Location pos2 = this.getTopAbs();
+            Location pos2 = this.getTopAbs().withY(getArea().getMaxBuildHeight());
             connected_cache = Sets.newHashSet(this);
             CuboidRegion rg = new CuboidRegion(pos1.getBlockVector3(), pos2.getBlockVector3());
             regions_cache = Collections.singleton(rg);

Core/src/main/java/com/plotsquared/core/plot/PlotArea.java

@@ -34,8 +34,6 @@ import com.plotsquared.core.configuration.ConfigurationNode;
 import com.plotsquared.core.configuration.ConfigurationSection;
 import com.plotsquared.core.configuration.ConfigurationUtil;
 import com.plotsquared.core.configuration.Settings;
-import com.plotsquared.core.configuration.caption.CaptionUtility;
-import com.plotsquared.core.configuration.caption.LocaleHolder;
 import com.plotsquared.core.configuration.caption.TranslatableCaption;
 import com.plotsquared.core.configuration.file.YamlConfiguration;
 import com.plotsquared.core.generator.GridPlotWorld;
@@ -54,7 +52,6 @@ import com.plotsquared.core.plot.flag.FlagParseException;
 import com.plotsquared.core.plot.flag.GlobalFlagContainer;
 import com.plotsquared.core.plot.flag.PlotFlag;
 import com.plotsquared.core.plot.flag.implementations.DoneFlag;
-import com.plotsquared.core.plot.flag.types.DoubleFlag;
 import com.plotsquared.core.queue.GlobalBlockQueue;
 import com.plotsquared.core.queue.QueueCoordinator;
 import com.plotsquared.core.util.MathMan;
@@ -144,8 +141,10 @@ public abstract class PlotArea {
     private boolean homeAllowNonmember = false;
     private BlockLoc nonmemberHome;
     private BlockLoc defaultHome;
-    private int maxBuildHeight = 256;
+    private int maxBuildHeight = PlotSquared.platform().versionMaxHeight() + 1; // Exclusive
-    private int minBuildHeight = 1;
+    private int minBuildHeight = PlotSquared.platform().versionMinHeight() + 1; // Inclusive
+    private int maxGenHeight = PlotSquared.platform().versionMaxHeight(); // Inclusive
+    private int minGenHeight = PlotSquared.platform().versionMinHeight(); // Inclusive
     private GameMode gameMode = GameModes.CREATIVE;
     private Map<String, PlotExpression> prices = new HashMap<>();
     private List<String> schematics = new ArrayList<>();
@@ -361,6 +360,8 @@ public abstract class PlotArea {
         this.worldBorder = config.getBoolean("world.border");
         this.maxBuildHeight = config.getInt("world.max_height");
         this.minBuildHeight = config.getInt("world.min_height");
+        this.minGenHeight = config.getInt("world.min_gen_height");
+        this.maxGenHeight = config.getInt("world.max_gen_height");
 
         switch (config.getString("world.gamemode").toLowerCase()) {
             case "creative", "c", "1" -> this.gameMode = GameModes.CREATIVE;
@@ -484,6 +485,8 @@ public abstract class PlotArea {
         options.put("home.nonmembers", position);
         options.put("world.max_height", this.getMaxBuildHeight());
         options.put("world.min_height", this.getMinBuildHeight());
+        options.put("world.min_gen_height", this.getMinGenHeight());
+        options.put("world.max_gen_height", this.getMaxGenHeight());
         options.put("world.gamemode", this.getGameMode().getName().toLowerCase());
         options.put("road.flags.default", null);
 
@@ -1078,8 +1081,8 @@ public abstract class PlotArea {
                     BlockVector2 pos1 = BlockVector2.at(value.getP1().getX(), value.getP1().getY());
                     BlockVector2 pos2 = BlockVector2.at(value.getP2().getX(), value.getP2().getY());
                     return new CuboidRegion(
-                            pos1.toBlockVector3(),
+                            pos1.toBlockVector3(getMinGenHeight()),
-                            pos2.toBlockVector3(Plot.MAX_HEIGHT - 1)
+                            pos2.toBlockVector3(getMaxGenHeight())
                     );
                 }
             };
@@ -1361,14 +1364,38 @@ public abstract class PlotArea {
         this.defaultHome = defaultHome;
     }
 
+    /**
+     * Get the maximum height players may build in. Exclusive.
+     */
     public int getMaxBuildHeight() {
         return this.maxBuildHeight;
     }
 
+    /**
+     * Get the minimum height players may build in. Inclusive.
+     */
     public int getMinBuildHeight() {
         return this.minBuildHeight;
     }
 
+    /**
+     * Get the min height from which P2 will generate blocks. Inclusive.
+     *
+     * @since TODO
+     */
+    public int getMinGenHeight() {
+        return this.minGenHeight;
+    }
+
+    /**
+     * Get the max height to which P2 will generate blocks. Inclusive.
+     *
+     * @since TODO
+     */
+    public int getMaxGenHeight() {
+        return this.maxGenHeight;
+    }
+
     public GameMode getGameMode() {
         return this.gameMode;
     }

Core/src/main/java/com/plotsquared/core/plot/PlotCluster.java

@@ -89,11 +89,17 @@ public class PlotCluster {
     }
 
     private void setRegion() {
-        this.region = RegionUtil.createRegion(this.pos1.getX(), this.pos2.getX(),
+        this.region = RegionUtil.createRegion(this.pos1.getX(), this.pos2.getX(), 0, 0,
                 this.pos1.getY(), this.pos2.getY()
         );
     }
 
+    /**
+     * Returns a region of PlotIDs
+     *
+     * @deprecated - returns region of IDs, not of actual blocks.
+     */
+    @Deprecated
     public CuboidRegion getRegion() {
         return this.region;
     }
@@ -165,7 +171,7 @@ public class PlotCluster {
         Consumer<Location> locationConsumer = toReturn ->
                 PlotSquared.platform().worldUtil().getHighestBlock(this.area.getWorldName(), toReturn.getX(), toReturn.getZ(),
                         highest -> {
-                            if (highest == 0) {
+                            if (highest <= area.getMinBuildHeight()) {
                                 highest = 63;
                             }
                             if (highest > toReturn.getY()) {
@@ -175,12 +181,12 @@ public class PlotCluster {
                             }
                         }
                 );
-        if (home.getY() == 0) {
+        if (home.getY() == Integer.MIN_VALUE) {
             // default pos
             Plot center = getCenterPlot();
             center.getHome(location -> {
                 Location toReturn = location;
-                if (toReturn.getY() == 0) {
+                if (toReturn.getY() <= area.getMinBuildHeight()) {
                     PlotManager manager = this.area.getPlotManager();
                     Location locationSign = manager.getSignLoc(center);
                     toReturn = toReturn.withY(locationSign.getY());

Core/src/main/java/com/plotsquared/core/plot/PlotModificationManager.java

@@ -69,8 +69,6 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
 
-import static com.plotsquared.core.plot.Plot.MAX_HEIGHT;
-
 /**
  * Manager that handles {@link Plot} modifications
  */
@@ -311,7 +309,7 @@ public final class PlotModificationManager {
                     return;
                 }
                 CuboidRegion region = regions.poll();
-                PlotSquared.platform().regionManager().setBiome(region, extendBiome, biome, plot.getWorldName(), this);
+                PlotSquared.platform().regionManager().setBiome(region, extendBiome, biome, plot.getArea(), this);
             }
         };
         run.run();
@@ -527,28 +525,6 @@ public final class PlotModificationManager {
         return false;
     }
 
-    /**
-     * Remove the south road section of a plot<br>
-     * - Used when a plot is merged<br>
-     *
-     * @param queue Nullable {@link QueueCoordinator}. If null, creates own queue and enqueues,
-     *              otherwise writes to the queue but does not enqueue.
-     */
-    public void removeRoadSouth(final @Nullable QueueCoordinator queue) {
-        if (this.plot.getArea().getType() != PlotAreaType.NORMAL && this.plot
-                .getArea()
-                .getTerrain() == PlotAreaTerrainType.ROAD) {
-            Plot other = this.plot.getRelative(Direction.SOUTH);
-            Location bot = other.getBottomAbs();
-            Location top = this.plot.getTopAbs();
-            Location pos1 = Location.at(this.plot.getWorldName(), bot.getX(), 0, top.getZ());
-            Location pos2 = Location.at(this.plot.getWorldName(), top.getX(), MAX_HEIGHT, bot.getZ());
-            PlotSquared.platform().regionManager().regenerateRegion(pos1, pos2, true, null);
-        } else if (this.plot.getArea().getTerrain() != PlotAreaTerrainType.ALL) { // no road generated => no road to remove
-            this.plot.getManager().removeRoadSouth(this.plot, queue);
-        }
-    }
-
     /**
      * Auto merge a plot in a specific direction.
      *
@@ -915,6 +891,28 @@ public final class PlotModificationManager {
         return this.setComponent(component, parsed.toPattern(), actor, queue);
     }
 
+    /**
+     * Remove the south road section of a plot<br>
+     * - Used when a plot is merged<br>
+     *
+     * @param queue Nullable {@link QueueCoordinator}. If null, creates own queue and enqueues,
+     *              otherwise writes to the queue but does not enqueue.
+     */
+    public void removeRoadSouth(final @Nullable QueueCoordinator queue) {
+        if (this.plot.getArea().getType() != PlotAreaType.NORMAL && this.plot
+                .getArea()
+                .getTerrain() == PlotAreaTerrainType.ROAD) {
+            Plot other = this.plot.getRelative(Direction.SOUTH);
+            Location bot = other.getBottomAbs();
+            Location top = this.plot.getTopAbs();
+            Location pos1 = Location.at(this.plot.getWorldName(), bot.getX(), plot.getArea().getMinGenHeight(), top.getZ());
+            Location pos2 = Location.at(this.plot.getWorldName(), top.getX(), plot.getArea().getMaxGenHeight(), bot.getZ());
+            PlotSquared.platform().regionManager().regenerateRegion(pos1, pos2, true, null);
+        } else if (this.plot.getArea().getTerrain() != PlotAreaTerrainType.ALL) { // no road generated => no road to remove
+            this.plot.getManager().removeRoadSouth(this.plot, queue);
+        }
+    }
+
     /**
      * Remove the east road section of a plot<br>
      * - Used when a plot is merged<br>
@@ -929,8 +927,8 @@ public final class PlotModificationManager {
             Plot other = this.plot.getRelative(Direction.EAST);
             Location bot = other.getBottomAbs();
             Location top = this.plot.getTopAbs();
-            Location pos1 = Location.at(this.plot.getWorldName(), top.getX(), 0, bot.getZ());
+            Location pos1 = Location.at(this.plot.getWorldName(), top.getX(), plot.getArea().getMinGenHeight(), bot.getZ());
-            Location pos2 = Location.at(this.plot.getWorldName(), bot.getX(), MAX_HEIGHT, top.getZ());
+            Location pos2 = Location.at(this.plot.getWorldName(), bot.getX(), plot.getArea().getMaxGenHeight(), top.getZ());
             PlotSquared.platform().regionManager().regenerateRegion(pos1, pos2, true, null);
         } else if (this.plot.getArea().getTerrain() != PlotAreaTerrainType.ALL) { // no road generated => no road to remove
             this.plot.getArea().getPlotManager().removeRoadEast(this.plot, queue);
@@ -948,8 +946,8 @@ public final class PlotModificationManager {
                 .getArea()
                 .getTerrain() == PlotAreaTerrainType.ROAD) {
             Plot other = this.plot.getRelative(1, 1);
-            Location pos1 = this.plot.getTopAbs().add(1, 0, 1).withY(0);
+            Location pos1 = this.plot.getTopAbs().add(1, 0, 1);
-            Location pos2 = other.getBottomAbs().subtract(1, 0, 1).withY(MAX_HEIGHT);
+            Location pos2 = other.getBottomAbs().subtract(1, 0, 1);
             PlotSquared.platform().regionManager().regenerateRegion(pos1, pos2, true, null);
         } else if (this.plot.getArea().getTerrain() != PlotAreaTerrainType.ALL) { // no road generated => no road to remove
             this.plot.getArea().getPlotManager().removeRoadSouthEast(this.plot, queue);

Core/src/main/java/com/plotsquared/core/queue/BasicQueueCoordinator.java

@@ -101,7 +101,7 @@ public abstract class BasicQueueCoordinator extends QueueCoordinator {
 
     @Override
     public boolean setBlock(int x, int y, int z, @NonNull BaseBlock id) {
-        if ((y > 255) || (y < 0)) {
+        if ((y > world.getMaxY()) || (y < world.getMinY())) {
             return false;
         }
         LocalChunk chunk = getChunk(x >> 4, z >> 4);
@@ -121,7 +121,7 @@ public abstract class BasicQueueCoordinator extends QueueCoordinator {
     @Override
     public boolean setBiome(int x, int z, @NonNull BiomeType biomeType) {
         LocalChunk chunk = getChunk(x >> 4, z >> 4);
-        for (int y = 0; y < 256; y++) {
+        for (int y = world.getMinY(); y <= world.getMaxY(); y++) {
             chunk.setBiome(x & 15, y, z & 15, biomeType);
         }
         settingBiomes = true;

Core/src/main/java/com/plotsquared/core/queue/ChunkQueueCoordinator.java

@@ -54,12 +54,12 @@ public class ChunkQueueCoordinator extends ScopedQueueCoordinator {
             @NonNull BlockVector3 top,
             boolean biomes
     ) {
-        super(null, Location.at("", 0, 0, 0), Location.at("", 15, 255, 15));
+        super(null, Location.at("", 0, weWorld.getMinY(), 0), Location.at("", 15, weWorld.getMaxY(), 15));
         this.weWorld = weWorld;
         this.width = top.getX() - bot.getX() + 1;
         this.length = top.getZ() - bot.getZ() + 1;
-        this.result = new BlockState[256][width][length];
+        this.result = new BlockState[weWorld.getMaxY() - weWorld.getMinY() + 1][width][length];
-        this.biomeResult = biomes ? new BiomeType[256][width][length] : null;
+        this.biomeResult = biomes ? new BiomeType[weWorld.getMaxY() - weWorld.getMinY() + 1][width][length] : null;
         this.bot = bot;
         this.top = top;
     }
@@ -71,7 +71,7 @@ public class ChunkQueueCoordinator extends ScopedQueueCoordinator {
     @Override
     public boolean setBiome(int x, int z, @NonNull BiomeType biomeType) {
         if (this.biomeResult != null) {
-            for (int y = 0; y < 256; y++) {
+            for (int y = weWorld.getMinY(); y <= weWorld.getMaxY(); y++) {
                 this.storeCacheBiome(x, y, z, biomeType);
             }
             return true;
@@ -101,9 +101,10 @@ public class ChunkQueueCoordinator extends ScopedQueueCoordinator {
     }
 
     private void storeCache(final int x, final int y, final int z, final @NonNull BlockState id) {
-        BlockState[][] resultY = result[y];
+        int yIndex = getYIndex(y);
+        BlockState[][] resultY = result[yIndex];
         if (resultY == null) {
-            result[y] = resultY = new BlockState[length][];
+            result[yIndex] = resultY = new BlockState[length][];
         }
         BlockState[] resultYZ = resultY[z];
         if (resultYZ == null) {
@@ -113,9 +114,10 @@ public class ChunkQueueCoordinator extends ScopedQueueCoordinator {
     }
 
     private void storeCacheBiome(final int x, final int y, final int z, final @NonNull BiomeType id) {
-        BiomeType[][] resultY = biomeResult[y];
+        int yIndex = getYIndex(y);
+        BiomeType[][] resultY = biomeResult[yIndex];
         if (resultY == null) {
-            biomeResult[y] = resultY = new BiomeType[length][];
+            biomeResult[yIndex] = resultY = new BiomeType[length][];
         }
         BiomeType[] resultYZ = resultY[z];
         if (resultYZ == null) {
@@ -132,7 +134,7 @@ public class ChunkQueueCoordinator extends ScopedQueueCoordinator {
 
     @Override
     public @Nullable BlockState getBlock(int x, int y, int z) {
-        BlockState[][] blocksY = result[y];
+        BlockState[][] blocksY = result[getYIndex(y)];
         if (blocksY != null) {
             BlockState[] blocksYZ = blocksY[z];
             if (blocksYZ != null) {
@@ -157,4 +159,8 @@ public class ChunkQueueCoordinator extends ScopedQueueCoordinator {
         return Location.at(getWorld().getName(), bot.getX(), bot.getY(), bot.getZ());
     }
 
+    private int getYIndex(int y) {
+        return y - weWorld.getMinY();
+    }
+
 }

Core/src/main/java/com/plotsquared/core/queue/LocalChunk.java

@@ -42,6 +42,7 @@ public class LocalChunk {
     private final QueueCoordinator parent;
     private final int x;
     private final int z;
+    private final int minSection;
 
     private final BaseBlock[][] baseblocks;
     private final BiomeType[][] biomes;
@@ -52,8 +53,10 @@ public class LocalChunk {
         this.parent = parent;
         this.x = x;
         this.z = z;
-        baseblocks = new BaseBlock[16][];
+        this.minSection = parent.getMinLayer();
-        biomes = new BiomeType[16][];
+        int sections = parent.getMaxLayer() - parent.getMinLayer() + 1;
+        baseblocks = new BaseBlock[sections][];
+        biomes = new BiomeType[sections][];
     }
 
     public @NonNull QueueCoordinator getParent() {
@@ -68,6 +71,15 @@ public class LocalChunk {
         return this.z;
     }
 
+    /**
+     * Get the minimum layer position stored (usually -4 or 0).
+     *
+     * @since TODO
+     */
+    public int getMinSection() {
+        return this.minSection;
+    }
+
     public @NonNull BaseBlock[][] getBaseblocks() {
         return this.baseblocks;
     }
@@ -81,7 +93,7 @@ public class LocalChunk {
     }
 
     public void setBiome(final int x, final int y, final int z, final @NonNull BiomeType biomeType) {
-        final int i = y >> 4;
+        final int i = getLayerIndex(y);
         final int j = ChunkUtil.getJ(x, y, z);
         BiomeType[] array = this.biomes[i];
         if (array == null) {
@@ -96,7 +108,7 @@ public class LocalChunk {
     }
 
     public void setBlock(final int x, final int y, final int z, final @NonNull BaseBlock baseBlock) {
-        final int i = y >> 4;
+        final int i = getLayerIndex(y);
         final int j = ChunkUtil.getJ(x, y, z);
         BaseBlock[] array = baseblocks[i];
         if (array == null) {
@@ -117,4 +129,8 @@ public class LocalChunk {
         return this.entities;
     }
 
+    private int getLayerIndex(final int y) {
+        return (y >> 4) - minSection;
+    }
+
 }

Core/src/main/java/com/plotsquared/core/queue/LocationOffsetDelegateQueueCoordinator.java

@@ -87,11 +87,14 @@ public class LocationOffsetDelegateQueueCoordinator extends DelegateQueueCoordin
 
     @Override
     public boolean setBiome(int x, int z, @NonNull BiomeType biome) {
-        boolean result = true;
+        try {
-        for (int y = 0; y < 256; y++) {
+            if (canPlace[x - blockX][z - blockZ]) {
-            result &= this.setBiome(x, y, z, biome);
+                return super.setBiome(x, z, biome);
+            }
+        } catch (final Exception e) {
+            throw e;
         }
-        return result;
+        return false;
     }
 
     @Override

Core/src/main/java/com/plotsquared/core/queue/QueueCoordinator.java

@@ -75,12 +75,29 @@ public abstract class QueueCoordinator {
      * @param x chunk x coordinate
      * @param z chunk z coordinate
      * @return a new {@link ScopedQueueCoordinator}
+     * @deprecated Use {@link ScopedQueueCoordinator#getForChunk(int, int, int, int)}
      */
+    @Deprecated(forRemoval = true, since = "TODO")
     public ScopedQueueCoordinator getForChunk(int x, int z) {
+        if (getWorld() == null) {
+            return getForChunk(x, z, PlotSquared.platform().versionMinHeight(), PlotSquared.platform().versionMaxHeight());
+        }
+        return getForChunk(x, z, getWorld().getMinY(), getWorld().getMaxY());
+    }
+
+    /**
+     * Get a {@link ScopedQueueCoordinator} limited to the chunk at the specific chunk Coordinates
+     *
+     * @param x chunk x coordinate
+     * @param z chunk z coordinate
+     * @return a new {@link ScopedQueueCoordinator}
+     * @since TODO
+     */
+    public ScopedQueueCoordinator getForChunk(int x, int z, int minY, int maxY) {
         int bx = x << 4;
         int bz = z << 4;
-        return new ScopedQueueCoordinator(this, Location.at(getWorld().getName(), bx, 0, bz),
+        return new ScopedQueueCoordinator(this, Location.at(getWorld().getName(), bx, minY, bz),
-                Location.at(getWorld().getName(), bx + 15, 255, bz + 255)
+                Location.at(getWorld().getName(), bx + 15, maxY, bz + 15)
         );
     }
 
@@ -404,7 +421,7 @@ public abstract class QueueCoordinator {
      */
     public void setCuboid(@NonNull Location pos1, @NonNull Location pos2, @NonNull BlockState block) {
         int yMin = Math.min(pos1.getY(), pos2.getY());
-        int yMax = Math.min(255, Math.max(pos1.getY(), pos2.getY()));
+        int yMax = Math.max(pos1.getY(), pos2.getY());
         int xMin = Math.min(pos1.getX(), pos2.getX());
         int xMax = Math.max(pos1.getX(), pos2.getX());
         int zMin = Math.min(pos1.getZ(), pos2.getZ());
@@ -427,7 +444,7 @@ public abstract class QueueCoordinator {
      */
     public void setCuboid(@NonNull Location pos1, @NonNull Location pos2, @NonNull Pattern blocks) {
         int yMin = Math.min(pos1.getY(), pos2.getY());
-        int yMax = Math.min(255, Math.max(pos1.getY(), pos2.getY()));
+        int yMax = Math.max(pos1.getY(), pos2.getY());
         int xMin = Math.min(pos1.getX(), pos2.getX());
         int xMax = Math.max(pos1.getX(), pos2.getX());
         int zMin = Math.min(pos1.getZ(), pos2.getZ());
@@ -450,7 +467,7 @@ public abstract class QueueCoordinator {
      */
     public void setBiomeCuboid(@NonNull Location pos1, @NonNull Location pos2, @NonNull BiomeType biome) {
         int yMin = Math.min(pos1.getY(), pos2.getY());
-        int yMax = Math.min(255, Math.max(pos1.getY(), pos2.getY()));
+        int yMax = Math.max(pos1.getY(), pos2.getY());
         int xMin = Math.min(pos1.getX(), pos2.getX());
         int xMax = Math.max(pos1.getX(), pos2.getX());
         int zMin = Math.min(pos1.getZ(), pos2.getZ());
@@ -464,4 +481,32 @@ public abstract class QueueCoordinator {
         }
     }
 
+    /**
+     * Get the min Y limit associated with the queue
+     */
+    protected int getMinY() {
+        return getWorld() != null ? getWorld().getMinY() : PlotSquared.platform().versionMinHeight();
+    }
+
+    /**
+     * Get the max Y limit associated with the queue
+     */
+    protected int getMaxY() {
+        return getWorld() != null ? getWorld().getMinY() : PlotSquared.platform().versionMaxHeight();
+    }
+
+    /**
+     * Get the min chunk layer associated with the queue. Usually 0 or -4;
+     */
+    protected int getMinLayer() {
+        return (getWorld() != null ? getWorld().getMinY() : PlotSquared.platform().versionMinHeight()) >> 4;
+    }
+
+    /**
+     * Get the max chunk layer associated with the queue. Usually 15 or 19
+     */
+    protected int getMaxLayer() {
+        return (getWorld() != null ? getWorld().getMaxY() : PlotSquared.platform().versionMaxHeight()) >> 4;
+    }
+
 }

Core/src/main/java/com/plotsquared/core/queue/ScopedQueueCoordinator.java

@@ -39,6 +39,8 @@ import org.checkerframework.checker.nullness.qual.Nullable;
  */
 public class ScopedQueueCoordinator extends DelegateQueueCoordinator {
 
+    private final Location min;
+    private final Location max;
     private final int minX;
     private final int minY;
     private final int minZ;
@@ -51,8 +53,13 @@ public class ScopedQueueCoordinator extends DelegateQueueCoordinator {
     private final int dy;
     private final int dz;
 
+    /**
+     * Create a new ScopedQueueCoordinator instance that delegates to a given QueueCoordinator. Locations are inclusive.
+     */
     public ScopedQueueCoordinator(@Nullable QueueCoordinator parent, @NonNull Location min, @NonNull Location max) {
         super(parent);
+        this.min = min;
+        this.max = max;
         this.minX = min.getX();
         this.minY = min.getY();
         this.minZ = min.getZ();
@@ -112,11 +119,11 @@ public class ScopedQueueCoordinator extends DelegateQueueCoordinator {
     }
 
     public @NonNull Location getMin() {
-        return Location.at(this.getWorld().getName(), this.minX, this.minY, this.minZ);
+        return min;
     }
 
     public @NonNull Location getMax() {
-        return Location.at(this.getWorld().getName(), this.maxX, this.maxY, this.maxZ);
+        return max;
     }
 
 }

Core/src/main/java/com/plotsquared/core/util/ChunkManager.java

@@ -31,6 +31,7 @@ import com.plotsquared.core.queue.QueueCoordinator;
 import com.plotsquared.core.queue.ScopedQueueCoordinator;
 import com.plotsquared.core.util.task.RunnableVal;
 import com.sk89q.worldedit.math.BlockVector2;
+import com.sk89q.worldedit.world.World;
 
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
@@ -47,18 +48,16 @@ public abstract class ChunkManager {
             String world,
             BlockVector2 loc
     ) {
-        QueueCoordinator queue = PlotSquared.platform().globalBlockQueue().getNewQueue(PlotSquared
+        World weWorld = PlotSquared.platform().worldUtil().getWeWorld(world);
-                .platform()
+        QueueCoordinator queue = PlotSquared.platform().globalBlockQueue().getNewQueue(weWorld);
-                .worldUtil()
-                .getWeWorld(world));
         if (PlotSquared.get().getPlotAreaManager().isAugmented(world) && PlotSquared.get().isNonStandardGeneration(world, loc)) {
             int blockX = loc.getX() << 4;
             int blockZ = loc.getZ() << 4;
             ScopedQueueCoordinator scoped =
                     new ScopedQueueCoordinator(
                             queue,
-                            Location.at(world, blockX, 0, blockZ),
+                            Location.at(world, blockX, weWorld.getMinY(), blockZ),
-                            Location.at(world, blockX + 15, 255, blockZ + 15)
+                            Location.at(world, blockX + 15, weWorld.getMaxY(), blockZ + 15)
                     );
             if (force != null) {
                 force.run(scoped);

Core/src/main/java/com/plotsquared/core/util/ChunkUtil.java

@@ -39,30 +39,27 @@ public class ChunkUtil {
      * - Used for efficient world generation<br>
      */
     private static final short[] x_loc;
-    private static final short[][] y_loc;
+    private static final short[] y_loc;
     private static final short[] z_loc;
     private static final short[][][] CACHE_J;
 
     static {
         x_loc = new short[4096];
-        y_loc = new short[16][4096];
+        y_loc = new short[4096];
         z_loc = new short[4096];
-        for (int i = 0; i < 16; i++) {
+        for (int j = 0; j < 4096; j++) {
-            int i4 = i << 4;
+            int y = j >> 8;
-            for (int j = 0; j < 4096; j++) {
+            int a = j - ((y & 0xF) << 8);
-                int y = i4 + (j >> 8);
+            int z1 = a >> 4;
-                int a = j - ((y & 0xF) << 8);
+            int x1 = a - (z1 << 4);
-                int z1 = a >> 4;
+            x_loc[j] = (short) x1;
-                int x1 = a - (z1 << 4);
+            y_loc[j] = (short) y;
-                x_loc[j] = (short) x1;
+            z_loc[j] = (short) z1;
-                y_loc[i][j] = (short) y;
-                z_loc[j] = (short) z1;
-            }
         }
-        CACHE_J = new short[256][16][16];
+        CACHE_J = new short[16][16][16];
         for (int x = 0; x < 16; x++) {
             for (int z = 0; z < 16; z++) {
-                for (int y = 0; y < 256; y++) {
+                for (int y = 0; y < 16; y++) {
                     short j = (short) ((y & 0xF) << 8 | z << 4 | x);
                     CACHE_J[y][x][z] = j;
                 }
@@ -83,7 +80,7 @@ public class ChunkUtil {
      * @return J value for xyz position in Array[4096].
      */
     public static int getJ(int x, int y, int z) {
-        return CACHE_J[y][x][z];
+        return CACHE_J[y & 15][x & 15][z & 15];
     }
 
     /**
@@ -97,14 +94,14 @@ public class ChunkUtil {
     }
 
     /**
-     * Gets the y coordinate for specific I and J values for a Chunk 16x16x16x16 layerxyz Array[16][4096].
+     * Gets the y coordinate for specific I and J values for a Chunk Nx16x16x16 layerxyz Array[N][4096].
      *
-     * @param i Relative layer of the position in the layerxyz Array[16][4096].
+     * @param i Relative layer of the position in the layerxyz Array[16][4096]. May be negative.
      * @param j Position in the xyz Array[4096].
      * @return x coordinate within the chunk
      */
     public static int getY(int i, int j) {
-        return y_loc[i][j];
+        return (i << 4) + y_loc[j];
     }
 
     /**

Core/src/main/java/com/plotsquared/core/util/MainUtil.java

@@ -37,15 +37,21 @@ public class MainUtil {
      * Cache of mapping x,y,z coordinates to the chunk array<br>
      * - Used for efficient world generation<br>
      */
+    @Deprecated(forRemoval = true, since = "6.0.0")
     public static short[][] x_loc;
+    @Deprecated(forRemoval = true, since = "6.0.0")
     public static short[][] y_loc;
+    @Deprecated(forRemoval = true, since = "6.0.0")
     public static short[][] z_loc;
+    @Deprecated(forRemoval = true, since = "6.0.0")
     public static short[][][] CACHE_I = null;
+    @Deprecated(forRemoval = true, since = "6.0.0")
     public static short[][][] CACHE_J = null;
 
     /**
      * This cache is used for world generation and just saves a bit of calculation time when checking if something is in the plot area.
      */
+    @Deprecated(forRemoval = true, since = "6.0.0")
     public static void initCache() {
         if (x_loc == null) {
             x_loc = new short[16][4096];

Core/src/main/java/com/plotsquared/core/util/RegionManager.java

@@ -279,7 +279,10 @@ public abstract class RegionManager {
         fromQueue1.addReadChunks(new CuboidRegion(pos1.getBlockVector3(), pos2.getBlockVector3()).getChunks());
         fromQueue2.addReadChunks(new CuboidRegion(
                 swapPos.getBlockVector3(),
-                BlockVector3.at(swapPos.getX() + pos2.getX() - pos1.getX(), 0, swapPos.getZ() + pos2.getZ() - pos1.getZ())
+                BlockVector3.at(swapPos.getX() + pos2.getX() - pos1.getX(),
+                        pos1.getY(),
+                        swapPos.getZ() + pos2.getZ() - pos1.getZ()
+                )
         ).getChunks());
         QueueCoordinator toQueue1 = blockQueue.getNewQueue(world1);
         QueueCoordinator toQueue2 = blockQueue.getNewQueue(world2);
@@ -352,7 +355,7 @@ public abstract class RegionManager {
             int bz = Math.max(pos1.getZ(), cbz) & 15;
             int tx = Math.min(pos2.getX(), cbx + 15) & 15;
             int tz = Math.min(pos2.getZ(), cbz + 15) & 15;
-            for (int y = 0; y < 256; y++) {
+            for (int y = world1.getMinY(); y <= world1.getMaxY(); y++) {
                 for (int x = bx; x <= tx; x++) {
                     for (int z = bz; z <= tz; z++) {
                         int rx = cbx + x;
@@ -363,7 +366,10 @@ public abstract class RegionManager {
                     }
                 }
             }
-            Region region = new CuboidRegion(BlockVector3.at(cbx + bx, 0, cbz + bz), BlockVector3.at(cbx + tx, 255, cbz + tz));
+            Region region = new CuboidRegion(
+                    BlockVector3.at(cbx + bx, world1.getMinY(), cbz + bz),
+                    BlockVector3.at(cbx + tx, world1.getMaxY(), cbz + tz)
+            );
             toQueue.addEntities(world1.getEntities(region));
             if (removeEntities) {
                 for (Entity entity : world1.getEntities(region)) {
@@ -373,6 +379,7 @@ public abstract class RegionManager {
         });
     }
 
+    @Deprecated(forRemoval = true, since = "TODO")
     public void setBiome(
             final CuboidRegion region,
             final int extendBiome,
@@ -380,39 +387,35 @@ public abstract class RegionManager {
             final String world,
             final Runnable whenDone
     ) {
-        Location pos1 = Location
+        setBiome(region, extendBiome, biome, PlotSquared.get().getPlotAreaManager().getPlotAreas(world, region)[0], whenDone);
-                .at(
+    }
-                        world,
-                        region.getMinimumPoint().getX() - extendBiome,
-                        region.getMinimumPoint().getY(),
-                        region.getMinimumPoint().getZ() - extendBiome
-                );
-        Location pos2 = Location
-                .at(
-                        world,
-                        region.getMaximumPoint().getX() + extendBiome,
-                        region.getMaximumPoint().getY(),
-                        region.getMaximumPoint().getZ() + extendBiome
-                );
-        final QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(world));
 
-        final int minX = pos1.getX();
+    /**
-        final int minZ = pos1.getZ();
+     * Set a region to a biome type.
-        final int maxX = pos2.getX();
+     *
-        final int maxZ = pos2.getZ();
+     * @param region      region to set
+     * @param extendBiome how far outside the region to extent setting the biome too account for 3D biomes being 4x4
+     * @param biome       biome to set
+     * @param area        {@link PlotArea} in which the biome is being set
+     * @param whenDone    task to run when complete
+     * @since TODO
+     */
+    public void setBiome(
+            final CuboidRegion region,
+            final int extendBiome,
+            final BiomeType biome,
+            final PlotArea area,
+            final Runnable whenDone
+    ) {
+        final QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
         queue.addReadChunks(region.getChunks());
         queue.setChunkConsumer(blockVector2 -> {
-            final int cx = blockVector2.getX() << 4;
-            final int cz = blockVector2.getZ() << 4;
             WorldUtil.setBiome(
-                    world,
+                    area.getWorldName(),
-                    Math.max(minX, cx),
+                    region,
-                    Math.max(minZ, cz),
-                    Math.min(maxX, cx + 15),
-                    Math.min(maxZ, cz + 15),
                     biome
             );
-            worldUtil.refreshChunk(blockVector2.getBlockX(), blockVector2.getBlockZ(), world);
+            worldUtil.refreshChunk(blockVector2.getBlockX(), blockVector2.getBlockZ(), area.getWorldName());
         });
         queue.setCompleteTask(whenDone);
         queue.enqueue();

Core/src/main/java/com/plotsquared/core/util/RegionUtil.java

@@ -76,8 +76,9 @@ public class RegionUtil {
         return new CuboidRegion(min, max);
     }
 
+    @Deprecated(forRemoval = true, since = "TODO")
     public static CuboidRegion createRegion(int pos1x, int pos2x, int pos1z, int pos2z) {
-        return createRegion(pos1x, pos2x, 0, Plot.MAX_HEIGHT - 1, pos1z, pos2z);
+        return createRegion(pos1x, pos2x, 0, 255, pos1z, pos2z);
     }
 
     public static CuboidRegion createRegion(

Core/src/main/java/com/plotsquared/core/util/SchematicHandler.java

@@ -305,12 +305,13 @@ public abstract class SchematicHandler {
             final int WIDTH = dimension.getX();
             final int LENGTH = dimension.getZ();
             final int HEIGHT = dimension.getY();
+            final int worldHeight = plot.getArea().getMaxGenHeight() - plot.getArea().getMinGenHeight() + 1;
             // Validate dimensions
             CuboidRegion region = plot.getLargestRegion();
             boolean sizeMismatch =
                     ((region.getMaximumPoint().getX() - region.getMinimumPoint().getX() + xOffset + 1) < WIDTH) || (
                             (region.getMaximumPoint().getZ() - region.getMinimumPoint().getZ() + zOffset + 1) < LENGTH) || (HEIGHT
-                            > 256);
+                            > worldHeight);
             if (!Settings.Schematics.PASTE_MISMATCHES && sizeMismatch) {
                 actor.sendMessage(TranslatableCaption.of("schematics.schematic_size_mismatch"));
                 TaskManager.runTask(whenDone);
@@ -321,14 +322,14 @@ public abstract class SchematicHandler {
             // Calculate the optimal height to paste the schematic at
             final int y_offset_actual;
             if (autoHeight) {
-                if (HEIGHT >= 256) {
+                if (HEIGHT >= worldHeight) {
                     y_offset_actual = yOffset;
                 } else {
                     PlotArea pw = plot.getArea();
                     if (pw instanceof ClassicPlotWorld) {
                         y_offset_actual = yOffset + pw.getMinBuildHeight() + ((ClassicPlotWorld) pw).PLOT_HEIGHT;
                     } else {
-                        y_offset_actual = yOffset + 1 + this.worldUtil
+                        y_offset_actual = yOffset + pw.getMinBuildHeight() + this.worldUtil
                                 .getHighestBlockSynchronous(plot.getWorldName(), region.getMinimumPoint().getX() + 1,
                                         region.getMinimumPoint().getZ() + 1
                                 );
@@ -360,9 +361,9 @@ public abstract class SchematicHandler {
             // Paste schematic here
             final QueueCoordinator queue = plot.getArea().getQueue();
 
-            for (int ry = 0; ry < Math.min(256, HEIGHT); ry++) {
+            for (int ry = 0; ry < Math.min(worldHeight, HEIGHT); ry++) {
                 int yy = y_offset_actual + ry;
-                if (yy > 255 || yy < 0) {
+                if (yy > plot.getArea().getMaxGenHeight() || yy < plot.getArea().getMinGenHeight()) {
                     continue;
                 }
                 for (int rz = 0; rz < blockArrayClipboard.getDimensions().getZ(); rz++) {
@@ -379,18 +380,18 @@ public abstract class SchematicHandler {
                         BlockVector3 loc = BlockVector3.at(rx, ry, rz);
                         BaseBlock id = blockArrayClipboard.getFullBlock(loc);
                         queue.setBlock(xx, yy, zz, id);
-                        if (ry == 0) {
+                        BiomeType biome = blockArrayClipboard.getBiome(loc);
-                            BiomeType biome = blockArrayClipboard.getBiome(loc);
+                        queue.setBiome(xx, yy, zz, biome);
-                            queue.setBiome(xx, yy, zz, biome);
-                        }
                     }
                 }
             }
             if (actor != null && Settings.QUEUE.NOTIFY_PROGRESS) {
                 queue.addProgressSubscriber(subscriberFactory.createWithActor(actor));
             }
-            whenDone.value = true;
+            if (whenDone != null) {
-            queue.setCompleteTask(whenDone);
+                whenDone.value = true;
+                queue.setCompleteTask(whenDone);
+            }
             queue.enqueue();
         } catch (Exception e) {
             e.printStackTrace();

Core/src/main/java/com/plotsquared/core/util/WEManager.java

@@ -25,6 +25,7 @@
  */
 package com.plotsquared.core.util;
 
+import com.fastasyncworldedit.core.regions.RegionWrapper;
 import com.plotsquared.core.PlotSquared;
 import com.plotsquared.core.configuration.Settings;
 import com.plotsquared.core.location.Location;
@@ -91,10 +92,7 @@ public class WEManager {
         Location location = player.getLocation();
         String world = location.getWorldName();
         if (!PlotSquared.get().getPlotAreaManager().hasPlotArea(world)) {
-            regions.add(RegionUtil
+            regions.add(RegionWrapper.GLOBAL());
-                    .createRegion(Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MIN_VALUE,
-                            Integer.MAX_VALUE
-                    ));
             return regions;
         }
         PlotArea area = player.getApplicablePlotArea();

Core/src/main/java/com/plotsquared/core/util/WorldUtil.java

@@ -39,6 +39,7 @@ import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.CuboidRegion;
+import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockType;
@@ -78,14 +79,29 @@ public abstract class WorldUtil {
      * @param p2x   Max X
      * @param p2z   Max Z
      * @param biome Biome
+     * @deprecated use {@link WorldUtil#setBiome(String, CuboidRegion, BiomeType)}
      */
+    @Deprecated(forRemoval = true)
     public static void setBiome(String world, int p1x, int p1z, int p2x, int p2z, BiomeType biome) {
-        BlockVector3 pos1 = BlockVector2.at(p1x, p1z).toBlockVector3();
+        World weWorld = PlotSquared.platform().worldUtil().getWeWorld(world);
-        BlockVector3 pos2 = BlockVector2.at(p2x, p2z).toBlockVector3(Plot.MAX_HEIGHT - 1);
+        BlockVector3 pos1 = BlockVector2.at(p1x, p1z).toBlockVector3(weWorld.getMinY());
+        BlockVector3 pos2 = BlockVector2.at(p2x, p2z).toBlockVector3(weWorld.getMaxY());
         CuboidRegion region = new CuboidRegion(pos1, pos2);
         PlotSquared.platform().worldUtil().setBiomes(world, region, biome);
     }
 
+    /**
+     * Set the biome in a region
+     *
+     * @param world  World name
+     * @param region Region
+     * @param biome  Biome
+     * @since TODO
+     */
+    public static void setBiome(String world, final CuboidRegion region, BiomeType biome) {
+        PlotSquared.platform().worldUtil().setBiomes(world, region, biome);
+    }
+
     /**
      * Check if a given world name corresponds to a real world
      *
@@ -217,11 +233,14 @@ public abstract class WorldUtil {
     /**
      * Set the biome in a region
      *
-     * @param world  World name
+     * @param worldName World name
-     * @param region Region
+     * @param region    Region
-     * @param biome  New biome
+     * @param biome     New biome
      */
-    public abstract void setBiomes(@NonNull String world, @NonNull CuboidRegion region, @NonNull BiomeType biome);
+    public void setBiomes(@NonNull String worldName, @NonNull CuboidRegion region, @NonNull BiomeType biome) {
+        final World world = getWeWorld(worldName);
+        region.forEach(bv -> world.setBiome(bv, biome));
+    }
 
     /**
      * Get the WorldEdit {@link com.sk89q.worldedit.world.World} corresponding to a world name

Core/src/main/resources/lang/messages_en.json

@@ -161,8 +161,9 @@
   "setup.road_width": "<gold>Road width</gold>",
   "setup.road_height": "<gold>Road height</gold>",
   "setup.road_block": "<gold>Road block</gold>",
-  "setup.wall_filling_block": "<gold>Wall filling block</gold><gray> (Block(s) been put under the plot border down to Y1)</gray>",
+  "setup.wall_filling_block": "<gold>Wall filling block</gold><gray> (Block(s) been put under the plot border down to min gen height + 1)</gray>",
   "setup.wall_height": "<gold>Wall height</gold>",
+  "setup.min_gen_height": "<gold>Minimum height from which to generate (for 1.18+ can be negative).</gold>",
   "setup.bedrock_boolean": "<gold>Whether a bedrock layer under the plot should be generated or not</gold>",
   "setup.singleplotarea_void_world": "<gold>Void world</gold>",
   "plotareatype.plot_area_type_normal": "<gray>Standard plot generation</gray>",