hollow-cube/lighting (#13)

* Lighting

* Remove invalidate

* Private

* Fix chunk loading

* Small fixes

* Fix loading light from anvil world

* Fix solid

* Temporary

* Fix tests, add seagrass and tall seagrass to diffusion list

* Make test faster, replace hephaistos

* Cleanup

* Assume failed test

* Fix chunk not getting invalidated

(cherry picked from commit f13a7b49fa)

demo/src/main/java/net/minestom/demo/PlayerInit.java

@@ -20,6 +20,7 @@ import net.minestom.server.event.server.ServerTickMonitorEvent;
 import net.minestom.server.instance.Instance;
 import net.minestom.server.instance.InstanceContainer;
 import net.minestom.server.instance.InstanceManager;
+import net.minestom.server.instance.LightingChunk;
 import net.minestom.server.instance.block.Block;
 import net.minestom.server.inventory.Inventory;
 import net.minestom.server.inventory.InventoryType;
@@ -123,6 +124,7 @@ public class PlayerInit {
 
         InstanceContainer instanceContainer = instanceManager.createInstanceContainer(DimensionType.OVERWORLD);
         instanceContainer.setGenerator(unit -> unit.modifier().fillHeight(0, 40, Block.STONE));
+        instanceContainer.setChunkSupplier(LightingChunk::new);
 
         if (false) {
             System.out.println("start");

src/main/java/net/minestom/server/collision/BoundingBox.java

@@ -4,6 +4,7 @@ import net.minestom.server.coordinate.Point;
 import net.minestom.server.coordinate.Pos;
 import net.minestom.server.coordinate.Vec;
 import net.minestom.server.entity.Entity;
+import net.minestom.server.instance.block.BlockFace;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -33,6 +34,11 @@ public final class BoundingBox implements Shape {
         this(width, height, depth, new Vec(-width / 2, 0, -depth / 2));
     }
 
+    @Override
+    public boolean isOccluded(@NotNull Shape shape, @NotNull BlockFace face) {
+        return false;
+    }
+
     @Override
     @ApiStatus.Experimental
     public boolean intersectBox(@NotNull Point positionRelative, @NotNull BoundingBox boundingBox) {

src/main/java/net/minestom/server/collision/CollisionUtils.java

@@ -113,7 +113,7 @@ public final class CollisionUtils {
         };
     }
 
-    public static Shape parseBlockShape(String str, Registry.BlockEntry blockEntry) {
-        return ShapeImpl.parseBlockFromRegistry(str, blockEntry);
+    public static Shape parseBlockShape(String collision, String occlusion, Registry.BlockEntry blockEntry) {
+        return ShapeImpl.parseBlockFromRegistry(collision, occlusion, blockEntry);
     }
 }

src/main/java/net/minestom/server/collision/Shape.java

@@ -1,11 +1,14 @@
 package net.minestom.server.collision;
 
 import net.minestom.server.coordinate.Point;
+import net.minestom.server.instance.block.BlockFace;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 @ApiStatus.Experimental
 public interface Shape {
+    boolean isOccluded(@NotNull Shape shape, @NotNull BlockFace face);
+
     /**
      * Checks if two bounding boxes intersect.
      *

src/main/java/net/minestom/server/collision/ShapeImpl.java

@@ -5,28 +5,37 @@ import it.unimi.dsi.fastutil.doubles.DoubleList;
 import net.minestom.server.coordinate.Point;
 import net.minestom.server.coordinate.Vec;
 import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.block.BlockFace;
 import net.minestom.server.registry.Registry;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 final class ShapeImpl implements Shape {
     private static final Pattern PATTERN = Pattern.compile("\\d.\\d{1,3}", Pattern.MULTILINE);
-    private final BoundingBox[] blockSections;
+    private final BoundingBox[] collisionBoundingBoxes;
     private final Point relativeStart, relativeEnd;
 
+    private final BoundingBox[] occlusionBoundingBoxes;
+    private final byte blockOcclusion;
+    private final byte airOcclusion;
+
     private final Registry.BlockEntry blockEntry;
     private Block block;
 
-    private ShapeImpl(BoundingBox[] boundingBoxes, Registry.BlockEntry blockEntry) {
-        this.blockSections = boundingBoxes;
+    private ShapeImpl(BoundingBox[] boundingBoxes, BoundingBox[] occlusionBoundingBoxes, Registry.BlockEntry blockEntry) {
+        this.collisionBoundingBoxes = boundingBoxes;
+        this.occlusionBoundingBoxes = occlusionBoundingBoxes;
         this.blockEntry = blockEntry;
-        // Find bounds
+
+        // Find bounds of collision
         {
             double minX = 1, minY = 1, minZ = 1;
             double maxX = 0, maxY = 0, maxZ = 0;
-            for (BoundingBox blockSection : blockSections) {
+            for (BoundingBox blockSection : collisionBoundingBoxes) {
                 // Min
                 if (blockSection.minX() < minX) minX = blockSection.minX();
                 if (blockSection.minY() < minY) minY = blockSection.minY();
@@ -39,16 +48,26 @@ final class ShapeImpl implements Shape {
             this.relativeStart = new Vec(minX, minY, minZ);
             this.relativeEnd = new Vec(maxX, maxY, maxZ);
         }
+
+        byte airFaces = 0;
+        byte fullFaces = 0;
+        for (BlockFace f : BlockFace.values()) {
+            final byte res = isFaceCovered(computeOcclusionSet(f));
+            airFaces |= ((res == 0) ? 0b1 : 0b0) << (byte) f.ordinal();
+            fullFaces |= ((res == 2) ? 0b1 : 0b0) << (byte) f.ordinal();
+        }
+
+        this.airOcclusion = airFaces;
+        this.blockOcclusion = fullFaces;
     }
 
-    static ShapeImpl parseBlockFromRegistry(String str, Registry.BlockEntry blockEntry) {
+    static private BoundingBox[] parseRegistryBoundingBoxString(String str) {
         final Matcher matcher = PATTERN.matcher(str);
         DoubleList vals = new DoubleArrayList();
         while (matcher.find()) {
             double newVal = Double.parseDouble(matcher.group());
             vals.add(newVal);
         }
-
         final int count = vals.size() / 6;
         BoundingBox[] boundingBoxes = new BoundingBox[count];
         for (int i = 0; i < count; ++i) {
@@ -66,7 +85,36 @@ final class ShapeImpl implements Shape {
             assert bb.minZ() == minZ;
             boundingBoxes[i] = bb;
         }
-        return new ShapeImpl(boundingBoxes, blockEntry);
+        return boundingBoxes;
+    }
+
+    /**
+     * Computes the occlusion for a given face.
+     *
+     * @param covering The rectangle set to check for covering.
+     * @return 0 if face is not covered, 1 if face is covered partially, 2 if face is fully covered.
+     */
+    private static byte isFaceCovered(List<Rectangle> covering) {
+        if (covering.isEmpty()) return 0;
+        Rectangle r = new Rectangle(0, 0, 1, 1);
+        List<Rectangle> toCover = new ArrayList<>();
+        toCover.add(r);
+        for (Rectangle rect : covering) {
+            List<Rectangle> nextCovering = new ArrayList<>();
+            for (Rectangle toCoverRect : toCover) {
+                List<Rectangle> remaining = getRemaining(rect, toCoverRect);
+                nextCovering.addAll(remaining);
+            }
+            toCover = nextCovering;
+            if (toCover.isEmpty()) return 2;
+        }
+        return 1;
+    }
+
+    static ShapeImpl parseBlockFromRegistry(String collision, String occlusion, Registry.BlockEntry blockEntry) {
+        BoundingBox[] collisionBoundingBoxes = parseRegistryBoundingBoxString(collision);
+        BoundingBox[] occlusionBoundingBoxes = blockEntry.occludes() ? parseRegistryBoundingBoxString(occlusion) : new BoundingBox[0];
+        return new ShapeImpl(collisionBoundingBoxes, occlusionBoundingBoxes, blockEntry);
     }
 
     @Override
@@ -79,9 +127,32 @@ final class ShapeImpl implements Shape {
         return relativeEnd;
     }
 
+    @Override
+    public boolean isOccluded(@NotNull Shape shape, @NotNull BlockFace face) {
+        final ShapeImpl shapeImpl = ((ShapeImpl) shape);
+        final boolean hasBlockOcclusion = (((blockOcclusion >> face.ordinal()) & 1) == 1);
+        final boolean hasBlockOcclusionOther = ((shapeImpl.blockOcclusion >> face.getOppositeFace().ordinal()) & 1) == 1;
+
+        if (blockEntry.lightEmission() > 0) return hasBlockOcclusionOther;
+
+        // If either face is full, return true
+        if (hasBlockOcclusion || hasBlockOcclusionOther) return true;
+
+        final boolean hasAirOcclusion = (((airOcclusion >> face.ordinal()) & 1) == 1);
+        final boolean hasAirOcclusionOther = ((shapeImpl.airOcclusion >> face.getOppositeFace().ordinal()) & 1) == 1;
+
+        // If a single face is air, return false
+        if (hasAirOcclusion || hasAirOcclusionOther) return false;
+
+        // Comparing two partial faces. Computation needed
+        List<Rectangle> allRectangles = shapeImpl.computeOcclusionSet(face.getOppositeFace());
+        allRectangles.addAll(computeOcclusionSet(face));
+        return isFaceCovered(allRectangles) == 2;
+    }
+
     @Override
     public boolean intersectBox(@NotNull Point position, @NotNull BoundingBox boundingBox) {
-        for (BoundingBox blockSection : blockSections) {
+        for (BoundingBox blockSection : collisionBoundingBoxes) {
             if (boundingBox.intersectBox(position, blockSection)) return true;
         }
         return false;
@@ -91,7 +162,7 @@ final class ShapeImpl implements Shape {
     public boolean intersectBoxSwept(@NotNull Point rayStart, @NotNull Point rayDirection,
                                      @NotNull Point shapePos, @NotNull BoundingBox moving, @NotNull SweepResult finalResult) {
         boolean hitBlock = false;
-        for (BoundingBox blockSection : blockSections) {
+        for (BoundingBox blockSection : collisionBoundingBoxes) {
             // Update final result if the temp result collision is sooner than the current final result
             if (RayUtils.BoundingBoxIntersectionCheck(moving, rayStart, rayDirection, blockSection, shapePos, finalResult)) {
                 finalResult.collidedShapePosition = shapePos;
@@ -108,4 +179,75 @@ final class ShapeImpl implements Shape {
         if (block == null) this.block = block = Block.fromStateId((short) blockEntry.stateId());
         return block;
     }
+
+    private List<Rectangle> computeOcclusionSet(BlockFace face) {
+        List<Rectangle> rSet = new ArrayList<>();
+        for (BoundingBox boundingBox : this.occlusionBoundingBoxes) {
+            switch (face) {
+                case NORTH -> // negative Z
+                {
+                    if (boundingBox.minZ() == 0)
+                        rSet.add(new Rectangle(boundingBox.minX(), boundingBox.minY(), boundingBox.maxX(), boundingBox.maxY()));
+                }
+                case SOUTH -> // positive Z
+                {
+                    if (boundingBox.maxZ() == 1)
+                        rSet.add(new Rectangle(boundingBox.minX(), boundingBox.minY(), boundingBox.maxX(), boundingBox.maxY()));
+                }
+                case WEST -> // negative X
+                {
+                    if (boundingBox.minX() == 0)
+                        rSet.add(new Rectangle(boundingBox.minY(), boundingBox.minZ(), boundingBox.maxY(), boundingBox.maxZ()));
+                }
+                case EAST -> // positive X
+                {
+                    if (boundingBox.maxX() == 1)
+                        rSet.add(new Rectangle(boundingBox.minY(), boundingBox.minZ(), boundingBox.maxY(), boundingBox.maxZ()));
+                }
+                case BOTTOM -> // negative Y
+                {
+                    if (boundingBox.minY() == 0)
+                        rSet.add(new Rectangle(boundingBox.minX(), boundingBox.minZ(), boundingBox.maxX(), boundingBox.maxZ()));
+                }
+                case TOP -> // positive Y
+                {
+                    if (boundingBox.maxY() == 1)
+                        rSet.add(new Rectangle(boundingBox.minX(), boundingBox.minZ(), boundingBox.maxX(), boundingBox.maxZ()));
+                }
+            }
+        }
+        return rSet;
+    }
+
+    private static List<Rectangle> getRemaining(Rectangle covering, Rectangle toCover) {
+        List<Rectangle> remaining = new ArrayList<>();
+        covering = clipRectangle(covering, toCover);
+        // Up
+        if (covering.y1() > toCover.y1()) {
+            remaining.add(new Rectangle(toCover.x1(), toCover.y1(), toCover.x2(), covering.y1()));
+        }
+        // Down
+        if (covering.y2() < toCover.y2()) {
+            remaining.add(new Rectangle(toCover.x1(), covering.y2(), toCover.x2(), toCover.y2()));
+        }
+        // Left
+        if (covering.x1() > toCover.x1()) {
+            remaining.add(new Rectangle(toCover.x1(), covering.y1(), covering.x1(), covering.y2()));
+        }
+        //Right
+        if (covering.x2() < toCover.x2()) {
+            remaining.add(new Rectangle(covering.x2(), covering.y1(), toCover.x2(), covering.y2()));
+        }
+        return remaining;
+    }
+
+    private static Rectangle clipRectangle(Rectangle covering, Rectangle toCover) {
+        final double x1 = Math.max(covering.x1(), toCover.x1());
+        final double y1 = Math.max(covering.y1(), toCover.y1());
+        final double x2 = Math.min(covering.x2(), toCover.x2());
+        final double y2 = Math.min(covering.y2(), toCover.y2());
+        return new Rectangle(x1, y1, x2, y2);
+    }
+
+    private record Rectangle(double x1, double y1, double x2, double y2) { }
 }

src/main/java/net/minestom/server/instance/AnvilLoader.java

@@ -101,7 +101,7 @@ public class AnvilLoader implements IChunkLoader {
 
         final ChunkReader chunkReader = new ChunkReader(chunkData);
 
-        Chunk chunk = new DynamicChunk(instance, chunkX, chunkZ);
+        Chunk chunk = instance.getChunkSupplier().createChunk(instance, chunkX, chunkZ);
         synchronized (chunk) {
             var yRange = chunkReader.getYRange();
             if (yRange.getStart() < instance.getDimensionType().getMinY()) {
@@ -375,8 +375,8 @@ public class AnvilLoader implements IChunkLoader {
             ChunkSectionWriter sectionWriter = new ChunkSectionWriter(SupportedVersion.Companion.getLatest(), (byte) sectionY);
 
             Section section = chunk.getSection(sectionY);
-            sectionWriter.setSkyLights(section.getSkyLight());
-            sectionWriter.setBlockLights(section.getBlockLight());
+            sectionWriter.setSkyLights(section.skyLight().array());
+            sectionWriter.setBlockLights(section.blockLight().array());
 
             BiomePalette biomePalette = new BiomePalette();
             BlockPalette blockPalette = new BlockPalette();

src/main/java/net/minestom/server/instance/DynamicChunk.java

@@ -39,7 +39,7 @@ import static net.minestom.server.utils.chunk.ChunkUtils.toSectionRelativeCoordi
  */
 public class DynamicChunk extends Chunk {
 
-    private List<Section> sections;
+    protected List<Section> sections;
 
     // Key = ChunkUtils#getBlockIndex
     protected final Int2ObjectOpenHashMap<Block> entries = new Int2ObjectOpenHashMap<>(0);
@@ -47,7 +47,6 @@ public class DynamicChunk extends Chunk {
 
     private long lastChange;
     final CachedPacket chunkCache = new CachedPacket(this::createChunkPacket);
-    final CachedPacket lightCache = new CachedPacket(this::createLightPacket);
 
     public DynamicChunk(@NotNull Instance instance, int chunkX, int chunkZ) {
         super(instance, chunkX, chunkZ, true);
@@ -61,7 +60,7 @@ public class DynamicChunk extends Chunk {
         assertLock();
         this.lastChange = System.currentTimeMillis();
         this.chunkCache.invalidate();
-        this.lightCache.invalidate();
+
         // Update pathfinder
         if (columnarSpace != null) {
             final ColumnarOcclusionFieldList columnarOcclusionFieldList = columnarSpace.occlusionFields();
@@ -183,7 +182,7 @@ public class DynamicChunk extends Chunk {
         this.entries.clear();
     }
 
-    private synchronized @NotNull ChunkDataPacket createChunkPacket() {
+    private @NotNull ChunkDataPacket createChunkPacket() {
         final NBTCompound heightmapsNBT;
         // TODO: don't hardcode heightmaps
         // Heightmap
@@ -203,20 +202,25 @@ public class DynamicChunk extends Chunk {
                     "WORLD_SURFACE", NBT.LongArray(encodeBlocks(worldSurface, bitsForHeight))));
         }
         // Data
-        final byte[] data = ObjectPool.PACKET_POOL.use(buffer ->
-                NetworkBuffer.makeArray(networkBuffer -> {
-                    for (Section section : sections) networkBuffer.write(section);
-                }));
+
+        final byte[] data;
+        synchronized (this) {
+            data = ObjectPool.PACKET_POOL.use(buffer ->
+                    NetworkBuffer.makeArray(networkBuffer -> {
+                        for (Section section : sections) networkBuffer.write(section);
+                    }));
+        }
+
         return new ChunkDataPacket(chunkX, chunkZ,
                 new ChunkData(heightmapsNBT, data, entries),
-                createLightData());
+                createLightData(true));
     }
 
-    private synchronized @NotNull UpdateLightPacket createLightPacket() {
-        return new UpdateLightPacket(chunkX, chunkZ, createLightData());
+    @NotNull UpdateLightPacket createLightPacket() {
+        return new UpdateLightPacket(chunkX, chunkZ, createLightData(false));
     }
 
-    private LightData createLightData() {
+    protected LightData createLightData(boolean sendAll) {
         BitSet skyMask = new BitSet();
         BitSet blockMask = new BitSet();
         BitSet emptySkyMask = new BitSet();
@@ -227,8 +231,8 @@ public class DynamicChunk extends Chunk {
         int index = 0;
         for (Section section : sections) {
             index++;
-            final byte[] skyLight = section.getSkyLight();
-            final byte[] blockLight = section.getBlockLight();
+            final byte[] skyLight = section.skyLight().array();
+            final byte[] blockLight = section.blockLight().array();
             if (skyLight.length != 0) {
                 skyLights.add(skyLight);
                 skyMask.set(index);

src/main/java/net/minestom/server/instance/Instance.java

@@ -34,6 +34,7 @@ import net.minestom.server.timer.Scheduler;
 import net.minestom.server.utils.ArrayUtils;
 import net.minestom.server.utils.PacketUtils;
 import net.minestom.server.utils.chunk.ChunkCache;
+import net.minestom.server.utils.chunk.ChunkSupplier;
 import net.minestom.server.utils.chunk.ChunkUtils;
 import net.minestom.server.utils.time.Cooldown;
 import net.minestom.server.utils.time.TimeUnit;
@@ -278,6 +279,14 @@ public abstract class Instance implements Block.Getter, Block.Setter,
         setGenerator(chunkGenerator != null ? new ChunkGeneratorCompatibilityLayer(chunkGenerator) : null);
     }
 
+    public abstract void setChunkSupplier(@NotNull ChunkSupplier chunkSupplier);
+
+    /**
+     * Gets the chunk supplier of the instance.
+     * @return the chunk supplier of the instance
+     */
+    public abstract ChunkSupplier getChunkSupplier();
+
     /**
      * Gets the generator associated with the instance
      *

src/main/java/net/minestom/server/instance/InstanceContainer.java

@@ -328,9 +328,11 @@ public class InstanceContainer extends Instance {
                                 if (forkChunk != null) {
                                     applyFork(forkChunk, sectionModifier);
                                     // Update players
-                                    if (forkChunk instanceof DynamicChunk dynamicChunk) {
+                                    if (forkChunk instanceof LightingChunk lightingChunk) {
+                                        lightingChunk.chunkCache.invalidate();
+                                        lightingChunk.lightCache.invalidate();
+                                    } else if (forkChunk instanceof DynamicChunk dynamicChunk) {
                                         dynamicChunk.chunkCache.invalidate();
-                                        dynamicChunk.lightCache.invalidate();
                                     }
                                     forkChunk.sendChunk();
                                 } else {
@@ -427,6 +429,7 @@ public class InstanceContainer extends Instance {
      * @param chunkSupplier the new {@link ChunkSupplier} of this instance, chunks need to be non-null
      * @throws NullPointerException if {@code chunkSupplier} is null
      */
+    @Override
     public void setChunkSupplier(@NotNull ChunkSupplier chunkSupplier) {
         this.chunkSupplier = chunkSupplier;
     }

src/main/java/net/minestom/server/instance/LightingChunk.java

@@ -0,0 +1,384 @@
+package net.minestom.server.instance;
+
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.collision.Shape;
+import net.minestom.server.coordinate.Point;
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.block.BlockFace;
+import net.minestom.server.instance.light.Light;
+import net.minestom.server.network.packet.server.CachedPacket;
+import net.minestom.server.network.packet.server.play.data.LightData;
+import net.minestom.server.timer.ExecutionType;
+import net.minestom.server.timer.Task;
+import net.minestom.server.timer.TaskSchedule;
+import net.minestom.server.utils.NamespaceID;
+import net.minestom.server.utils.chunk.ChunkUtils;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class LightingChunk extends DynamicChunk {
+    private int[] heightmap;
+    final CachedPacket lightCache = new CachedPacket(this::createLightPacket);
+    boolean sendNeighbours = true;
+
+    enum LightType {
+        SKY,
+        BLOCK
+    }
+
+    private static final Set<NamespaceID> DIFFUSE_SKY_LIGHT = Set.of(
+            Block.COBWEB.namespace(),
+            Block.ICE.namespace(),
+            Block.HONEY_BLOCK.namespace(),
+            Block.SLIME_BLOCK.namespace(),
+            Block.WATER.namespace(),
+            Block.ACACIA_LEAVES.namespace(),
+            Block.AZALEA_LEAVES.namespace(),
+            Block.BIRCH_LEAVES.namespace(),
+            Block.DARK_OAK_LEAVES.namespace(),
+            Block.FLOWERING_AZALEA_LEAVES.namespace(),
+            Block.JUNGLE_LEAVES.namespace(),
+            Block.OAK_LEAVES.namespace(),
+            Block.SPRUCE_LEAVES.namespace(),
+            Block.SPAWNER.namespace(),
+            Block.BEACON.namespace(),
+            Block.END_GATEWAY.namespace(),
+            Block.CHORUS_PLANT.namespace(),
+            Block.CHORUS_FLOWER.namespace(),
+            Block.FROSTED_ICE.namespace(),
+            Block.SEAGRASS.namespace(),
+            Block.TALL_SEAGRASS.namespace(),
+            Block.LAVA.namespace()
+    );
+
+    public LightingChunk(@NotNull Instance instance, int chunkX, int chunkZ) {
+        super(instance, chunkX, chunkZ);
+    }
+
+    private boolean checkSkyOcclusion(Block block) {
+        if (block == Block.AIR) return false;
+        if (DIFFUSE_SKY_LIGHT.contains(block.namespace())) return true;
+
+        Shape shape = block.registry().collisionShape();
+        boolean occludesTop = Block.AIR.registry().collisionShape().isOccluded(shape, BlockFace.TOP);
+        boolean occludesBottom = Block.AIR.registry().collisionShape().isOccluded(shape, BlockFace.BOTTOM);
+
+        return occludesBottom || occludesTop;
+    }
+
+    private void invalidateSection(int coordinate) {
+        for (int i = -1; i <= 1; i++) {
+            for (int j = -1; j <= 1; j++) {
+                Chunk neighborChunk = instance.getChunk(chunkX + i, chunkZ + j);
+                if (neighborChunk == null) continue;
+
+                if (neighborChunk instanceof LightingChunk lightingChunk) {
+                    lightingChunk.lightCache.invalidate();
+                    lightingChunk.chunkCache.invalidate();
+                }
+
+                for (int k = -1; k <= 1; k++) {
+                    if (k + coordinate < neighborChunk.getMinSection() || k + coordinate >= neighborChunk.getMaxSection()) continue;
+                    neighborChunk.getSection(k + coordinate).blockLight().invalidate();
+                    neighborChunk.getSection(k + coordinate).skyLight().invalidate();
+                }
+            }
+        }
+    }
+
+    @Override
+    public void setBlock(int x, int y, int z, @NotNull Block block) {
+        super.setBlock(x, y, z, block);
+        this.heightmap = null;
+
+        // Invalidate neighbor chunks, since they can be updated by this block change
+        int coordinate = ChunkUtils.getChunkCoordinate(y);
+        invalidateSection(coordinate);
+
+        this.lightCache.invalidate();
+    }
+
+    public void sendLighting() {
+        if (!isLoaded()) return;
+        sendPacketToViewers(lightCache);
+    }
+
+    public int[] calculateHeightMap() {
+        if (this.heightmap != null) return this.heightmap;
+        var heightmap = new int[CHUNK_SIZE_X * CHUNK_SIZE_Z];
+
+        int minY = instance.getDimensionType().getMinY();
+        int maxY = instance.getDimensionType().getMinY() + instance.getDimensionType().getHeight();
+
+        synchronized (this) {
+            for (int x = 0; x < CHUNK_SIZE_X; x++) {
+                for (int z = 0; z < CHUNK_SIZE_Z; z++) {
+                    int height = maxY;
+                    while (height > minY) {
+                        Block block = getBlock(x, height, z, Condition.TYPE);
+                        if (checkSkyOcclusion(block)) break;
+                        height--;
+                    }
+                    heightmap[z << 4 | x] = (height + 1);
+                }
+            }
+        }
+
+        this.heightmap = heightmap;
+        return heightmap;
+    }
+
+    @Override
+    protected LightData createLightData(boolean sendAll) {
+        BitSet skyMask = new BitSet();
+        BitSet blockMask = new BitSet();
+        BitSet emptySkyMask = new BitSet();
+        BitSet emptyBlockMask = new BitSet();
+        List<byte[]> skyLights = new ArrayList<>();
+        List<byte[]> blockLights = new ArrayList<>();
+
+        int index = 0;
+        for (Section section : sections) {
+            boolean wasUpdatedBlock = false;
+            boolean wasUpdatedSky = false;
+
+            if (section.blockLight().requiresUpdate()) {
+                relightSection(instance, this.chunkX, index + minSection, chunkZ, LightType.BLOCK);
+                wasUpdatedBlock = true;
+            } else if (section.blockLight().requiresSend()) {
+                wasUpdatedBlock = true;
+            }
+
+            if (section.skyLight().requiresUpdate()) {
+                relightSection(instance, this.chunkX, index + minSection, chunkZ, LightType.SKY);
+                wasUpdatedSky = true;
+            } else if (section.skyLight().requiresSend()) {
+                wasUpdatedSky = true;
+            }
+
+            index++;
+
+            final byte[] skyLight = section.skyLight().array();
+            final byte[] blockLight = section.blockLight().array();
+
+            // System.out.println("Relit sky: " + wasUpdatedSky + " block: " + wasUpdatedBlock + " for section " + (index + minSection) + " in chunk " + chunkX + " " + chunkZ);
+
+            if ((wasUpdatedSky || sendAll) && this.instance.getDimensionType().isSkylightEnabled()) {
+                if (skyLight.length != 0) {
+                    skyLights.add(skyLight);
+                    skyMask.set(index);
+                } else {
+                    emptySkyMask.set(index);
+                }
+            }
+
+            if (wasUpdatedBlock || sendAll) {
+                if (blockLight.length != 0) {
+                    blockLights.add(blockLight);
+                    blockMask.set(index);
+                } else {
+                    emptyBlockMask.set(index);
+                }
+            }
+        }
+
+        if (sendNeighbours) {
+            updateAfterGeneration(this);
+            sendNeighbours = false;
+        }
+
+        return new LightData(true,
+                skyMask, blockMask,
+                emptySkyMask, emptyBlockMask,
+                skyLights, blockLights);
+    }
+
+    private static final Set<LightingChunk> sendQueue = ConcurrentHashMap.newKeySet();
+    private static Task sendingTask = null;
+
+    private static void updateAfterGeneration(LightingChunk chunk) {
+        for (int i = -1; i <= 1; i++) {
+            for (int j = -1; j <= 1; j++) {
+                Chunk neighborChunk = chunk.instance.getChunk(chunk.chunkX + i, chunk.chunkZ + j);
+                if (neighborChunk == null) continue;
+
+                if (neighborChunk instanceof LightingChunk lightingChunk) {
+                    sendQueue.add(lightingChunk);
+                }
+            }
+        }
+
+        if (sendingTask == null) {
+            sendingTask = MinecraftServer.getSchedulerManager().scheduleTask(() -> {
+                sendingTask = null;
+
+                for (LightingChunk f : sendQueue) {
+                    if (f.isLoaded()) {
+                        f.sections.forEach(s -> {
+                            s.blockLight().invalidate();
+                            s.skyLight().invalidate();
+                        });
+                        f.sendLighting();
+                        sendQueue.remove(f);
+                    }
+
+                    f.chunkCache.invalidate();
+                }
+            }, TaskSchedule.tick(5), TaskSchedule.stop(), ExecutionType.ASYNC);
+        }
+    }
+
+    private static void flushQueue(Instance instance, Set<Point> queue, LightType type) {
+        var updateQueue =
+                queue.parallelStream()
+                        .map(sectionLocation -> {
+                            Chunk chunk = instance.getChunk(sectionLocation.blockX(), sectionLocation.blockZ());
+                            if (chunk == null) return null;
+
+                            if (type == LightType.BLOCK) {
+                                return chunk.getSection(sectionLocation.blockY()).blockLight()
+                                        .calculateExternal(instance, chunk, sectionLocation.blockY());
+                            } else {
+                                return chunk.getSection(sectionLocation.blockY()).skyLight()
+                                        .calculateExternal(instance, chunk, sectionLocation.blockY());
+                            }
+                        })
+                        .filter(Objects::nonNull)
+                        .toList()
+                        .parallelStream()
+                        .flatMap(light -> light.flip().stream())
+                        .collect(Collectors.toSet());
+
+        if (updateQueue.size() > 0) {
+            flushQueue(instance, updateQueue, type);
+        }
+    }
+
+    public static void relight(Instance instance, Collection<Chunk> chunks) {
+        Set<Point> toPropagate = chunks
+                .parallelStream()
+                .flatMap(chunk -> IntStream
+                        .range(chunk.getMinSection(), chunk.getMaxSection())
+                        .mapToObj(index -> Map.entry(index, chunk)))
+                .map(chunkIndex -> {
+                    final Chunk chunk = chunkIndex.getValue();
+                    final int section = chunkIndex.getKey();
+
+                    chunk.getSection(section).blockLight().invalidate();
+                    chunk.getSection(section).skyLight().invalidate();
+
+                    return new Vec(chunk.getChunkX(), section, chunk.getChunkZ());
+                }).collect(Collectors.toSet());
+
+        synchronized (instance) {
+            relight(instance, toPropagate, LightType.BLOCK);
+            relight(instance, toPropagate, LightType.SKY);
+        }
+    }
+
+    private static Set<Point> getNearbyRequired(Instance instance, Point point) {
+        Set<Point> collected = new HashSet<>();
+        collected.add(point);
+
+        for (int x = point.blockX() - 1; x <= point.blockX() + 1; x++) {
+            for (int z = point.blockZ() - 1; z <= point.blockZ() + 1; z++) {
+                Chunk chunkCheck = instance.getChunk(x, z);
+                if (chunkCheck == null) continue;
+
+                for (int y = point.blockY() - 1; y <= point.blockY() + 1; y++) {
+                    Point sectionPosition = new Vec(x, y, z);
+
+                    if (sectionPosition.blockY() < chunkCheck.getMaxSection() && sectionPosition.blockY() >= chunkCheck.getMinSection()) {
+                        Section s = chunkCheck.getSection(sectionPosition.blockY());
+                        if (!s.blockLight().requiresUpdate() && !s.skyLight().requiresUpdate()) continue;
+
+                        collected.add(sectionPosition);
+                    }
+                }
+            }
+        }
+
+        return collected;
+    }
+
+    private static Set<Point> collectRequiredNearby(Instance instance, Point point) {
+        final Set<Point> found = new HashSet<>();
+        final ArrayDeque<Point> toCheck = new ArrayDeque<>();
+
+        toCheck.add(point);
+        found.add(point);
+
+        while (toCheck.size() > 0) {
+            final Point current = toCheck.poll();
+            final Set<Point> nearby = getNearbyRequired(instance, current);
+            nearby.forEach(p -> {
+                if (!found.contains(p)) {
+                    found.add(p);
+                    toCheck.add(p);
+                }
+            });
+        }
+
+        return found;
+    }
+
+    static void relightSection(Instance instance, int chunkX, int sectionY, int chunkZ) {
+        relightSection(instance, chunkX, sectionY, chunkZ, LightType.BLOCK);
+        relightSection(instance, chunkX, sectionY, chunkZ, LightType.SKY);
+    }
+
+    private static void relightSection(Instance instance, int chunkX, int sectionY, int chunkZ, LightType type) {
+        Chunk c = instance.getChunk(chunkX, chunkZ);
+        if (c == null) return;
+
+        Set<Point> collected = collectRequiredNearby(instance, new Vec(chunkX, sectionY, chunkZ));
+        // System.out.println("Calculating " + chunkX + " " + sectionY + " " + chunkZ + " | " + collected.size());
+
+        synchronized (instance) {
+            relight(instance, collected, type);
+        }
+    }
+
+    private static void relight(Instance instance, Set<Point> sections, LightType type) {
+        Set<Point> toPropagate = sections
+                .parallelStream()
+                // .stream()
+                .map(chunkIndex -> {
+                    final Chunk chunk = instance.getChunk(chunkIndex.blockX(), chunkIndex.blockZ());
+                    final int section = chunkIndex.blockY();
+                    if (chunk == null) return null;
+                    if (type == LightType.BLOCK) return chunk.getSection(section).blockLight().calculateInternal(chunk.getInstance(), chunk.getChunkX(), section, chunk.getChunkZ());
+                    else return chunk.getSection(section).skyLight().calculateInternal(chunk.getInstance(), chunk.getChunkX(), section, chunk.getChunkZ());
+                }).filter(Objects::nonNull)
+                .flatMap(lightSet -> lightSet.flip().stream())
+                .collect(Collectors.toSet())
+                // .stream()
+                .parallelStream()
+                .flatMap(sectionLocation -> {
+                    final Chunk chunk = instance.getChunk(sectionLocation.blockX(), sectionLocation.blockZ());
+                    final int section = sectionLocation.blockY();
+                    if (chunk == null) return Stream.empty();
+
+                    final Light light = type == LightType.BLOCK ? chunk.getSection(section).blockLight() : chunk.getSection(section).skyLight();
+                    light.calculateExternal(chunk.getInstance(), chunk, section);
+
+                    return light.flip().stream();
+                }).collect(Collectors.toSet());
+
+        flushQueue(instance, toPropagate, type);
+    }
+
+    @Override
+    public @NotNull Chunk copy(@NotNull Instance instance, int chunkX, int chunkZ) {
+        LightingChunk lightingChunk = new LightingChunk(instance, chunkX, chunkZ);
+        lightingChunk.sections = sections.stream().map(Section::clone).toList();
+        lightingChunk.entries.putAll(entries);
+        return lightingChunk;
+    }
+}

src/main/java/net/minestom/server/instance/Section.java

@@ -1,5 +1,6 @@
 package net.minestom.server.instance;
 
+import net.minestom.server.instance.light.Light;
 import net.minestom.server.instance.palette.Palette;
 import net.minestom.server.network.NetworkBuffer;
 import org.jetbrains.annotations.NotNull;
@@ -7,22 +8,20 @@ import org.jetbrains.annotations.NotNull;
 import static net.minestom.server.network.NetworkBuffer.SHORT;
 
 public final class Section implements NetworkBuffer.Writer {
-    private Palette blockPalette;
-    private Palette biomePalette;
-    private byte[] skyLight;
-    private byte[] blockLight;
+    private final Palette blockPalette;
+    private final Palette biomePalette;
+    private final Light skyLight;
+    private final Light blockLight;
 
-    private Section(Palette blockPalette, Palette biomePalette,
-                    byte[] skyLight, byte[] blockLight) {
+    private Section(Palette blockPalette, Palette biomePalette) {
         this.blockPalette = blockPalette;
         this.biomePalette = biomePalette;
-        this.skyLight = skyLight;
-        this.blockLight = blockLight;
+        this.skyLight = Light.sky(blockPalette);
+        this.blockLight = Light.block(blockPalette);
     }
 
     public Section() {
-        this(Palette.blocks(), Palette.biomes(),
-                new byte[0], new byte[0]);
+        this(Palette.blocks(), Palette.biomes());
     }
 
     public Palette blockPalette() {
@@ -33,33 +32,14 @@ public final class Section implements NetworkBuffer.Writer {
         return biomePalette;
     }
 
-    public byte[] getSkyLight() {
-        return skyLight;
-    }
-
-    public void setSkyLight(byte[] skyLight) {
-        this.skyLight = skyLight;
-    }
-
-    public byte[] getBlockLight() {
-        return blockLight;
-    }
-
-    public void setBlockLight(byte[] blockLight) {
-        this.blockLight = blockLight;
-    }
-
     public void clear() {
         this.blockPalette.fill(0);
         this.biomePalette.fill(0);
-        this.skyLight = new byte[0];
-        this.blockLight = new byte[0];
     }
 
     @Override
     public @NotNull Section clone() {
-        return new Section(blockPalette.clone(), biomePalette.clone(),
-                skyLight.clone(), blockLight.clone());
+        return new Section(this.blockPalette.clone(), this.biomePalette.clone());
     }
 
     @Override
@@ -68,4 +48,20 @@ public final class Section implements NetworkBuffer.Writer {
         writer.write(blockPalette);
         writer.write(biomePalette);
     }
+
+    public void setSkyLight(byte[] copyArray) {
+        this.skyLight.set(copyArray);
+    }
+
+    public void setBlockLight(byte[] copyArray) {
+        this.blockLight.set(copyArray);
+    }
+
+    public Light skyLight() {
+        return skyLight;
+    }
+
+    public Light blockLight() {
+        return blockLight;
+    }
 }

src/main/java/net/minestom/server/instance/SharedInstance.java

@@ -6,6 +6,7 @@ import net.minestom.server.instance.block.Block;
 import net.minestom.server.instance.block.BlockFace;
 import net.minestom.server.instance.block.BlockHandler;
 import net.minestom.server.instance.generator.Generator;
+import net.minestom.server.utils.chunk.ChunkSupplier;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -75,6 +76,16 @@ public class SharedInstance extends Instance {
         return instanceContainer.saveChunksToStorage();
     }
 
+    @Override
+    public void setChunkSupplier(@NotNull ChunkSupplier chunkSupplier) {
+        instanceContainer.setChunkSupplier(chunkSupplier);
+    }
+
+    @Override
+    public ChunkSupplier getChunkSupplier() {
+        return instanceContainer.getChunkSupplier();
+    }
+
     @Override
     public @Nullable Generator generator() {
         return instanceContainer.generator();

src/main/java/net/minestom/server/instance/batch/AbsoluteBlockBatch.java

@@ -6,12 +6,16 @@ import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
 import net.minestom.server.instance.Chunk;
 import net.minestom.server.instance.Instance;
 import net.minestom.server.instance.InstanceContainer;
+import net.minestom.server.instance.LightingChunk;
 import net.minestom.server.instance.block.Block;
 import net.minestom.server.utils.chunk.ChunkUtils;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -125,6 +129,8 @@ public class AbsoluteBlockBatch implements Batch<Runnable> {
         final AbsoluteBlockBatch inverse = this.options.shouldCalculateInverse() ? new AbsoluteBlockBatch(inverseOption) : null;
         synchronized (chunkBatchesMap) {
             AtomicInteger counter = new AtomicInteger();
+            Set<Chunk> updated = ConcurrentHashMap.newKeySet();
+
             for (var entry : Long2ObjectMaps.fastIterable(chunkBatchesMap)) {
                 final long chunkIndex = entry.getLongKey();
                 final int chunkX = ChunkUtils.getChunkCoordX(chunkIndex);
@@ -146,6 +152,25 @@ public class AbsoluteBlockBatch implements Batch<Runnable> {
                                 callback.run();
                             }
                         }
+
+                        Set<Chunk> expanded = new HashSet<>();
+                        for (Chunk chunk : updated) {
+                            for (int i = -1; i <= 1; ++i) {
+                                for (int j = -1; j <= 1; ++j) {
+                                    Chunk toAdd = instance.getChunk(chunk.getChunkX() + i, chunk.getChunkZ() + j);
+                                    if (toAdd != null) {
+                                        expanded.add(toAdd);
+                                    }
+                                }
+                            }
+                        }
+
+                        // Update the chunk's light
+                        for (Chunk chunk : expanded) {
+                            if (chunk instanceof LightingChunk dc) {
+                                dc.sendLighting();
+                            }
+                        }
                     }
                 });
                 if (inverse != null) inverse.chunkBatchesMap.put(chunkIndex, chunkInverse);

src/main/java/net/minestom/server/instance/light/BlockLight.java

@@ -0,0 +1,359 @@
+package net.minestom.server.instance.light;
+
+import it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue;
+import net.minestom.server.coordinate.Point;
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.Chunk;
+import net.minestom.server.instance.Instance;
+import net.minestom.server.instance.Section;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.block.BlockFace;
+import net.minestom.server.instance.palette.Palette;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import static net.minestom.server.instance.light.LightCompute.*;
+
+final class BlockLight implements Light {
+    private final Palette blockPalette;
+
+    private byte[] content;
+    private byte[] contentPropagation;
+    private byte[] contentPropagationSwap;
+
+    private byte[][] borders;
+    private byte[][] bordersPropagation;
+    private byte[][] bordersPropagationSwap;
+    private boolean isValidBorders = true;
+    private boolean needsSend = true;
+    private Set<Point> toUpdateSet = new HashSet<>();
+
+    BlockLight(Palette blockPalette) {
+        this.blockPalette = blockPalette;
+    }
+
+    @Override
+    public Set<Point> flip() {
+        if (this.bordersPropagationSwap != null)
+            this.bordersPropagation = this.bordersPropagationSwap;
+
+        if (this.contentPropagationSwap != null)
+            this.contentPropagation = this.contentPropagationSwap;
+
+        this.bordersPropagationSwap = null;
+        this.contentPropagationSwap = null;
+
+        if (toUpdateSet == null) return Set.of();
+        return toUpdateSet;
+    }
+
+    static IntArrayFIFOQueue buildInternalQueue(Palette blockPalette, Block[] blocks) {
+        IntArrayFIFOQueue lightSources = new IntArrayFIFOQueue();
+        // Apply section light
+        blockPalette.getAllPresent((x, y, z, stateId) -> {
+            final Block block = Block.fromStateId((short) stateId);
+            assert block != null;
+            final byte lightEmission = (byte) block.registry().lightEmission();
+
+            final int index = x | (z << 4) | (y << 8);
+            blocks[index] = block;
+            if (lightEmission > 0) {
+                lightSources.enqueue(index | (lightEmission << 12));
+            }
+        });
+        return lightSources;
+    }
+
+    private static Block getBlock(Palette palette, int x, int y, int z) {
+        return Block.fromStateId((short)palette.get(x, y, z));
+    }
+
+    private static IntArrayFIFOQueue buildExternalQueue(Instance instance, Block[] blocks, Map<BlockFace, Point> neighbors, byte[][] borders) {
+        IntArrayFIFOQueue lightSources = new IntArrayFIFOQueue();
+
+        for (BlockFace face : BlockFace.values()) {
+            Point neighborSection = neighbors.get(face);
+            if (neighborSection == null) continue;
+
+            Chunk chunk = instance.getChunk(neighborSection.blockX(), neighborSection.blockZ());
+            if (chunk == null) continue;
+
+            byte[] neighborFace = chunk.getSection(neighborSection.blockY()).blockLight().getBorderPropagation(face.getOppositeFace());
+            if (neighborFace == null) continue;
+
+            for (int bx = 0; bx < 16; bx++) {
+                for (int by = 0; by < 16; by++) {
+                    final int borderIndex = bx * SECTION_SIZE + by;
+                    byte lightEmission = neighborFace[borderIndex];
+
+                    if (borders != null && borders[face.ordinal()] != null) {
+                        final int internalEmission = borders[face.ordinal()][borderIndex];
+                        if (lightEmission <= internalEmission) continue;
+                    }
+
+                    final int k = switch (face) {
+                        case WEST, BOTTOM, NORTH -> 0;
+                        case EAST, TOP, SOUTH -> 15;
+                    };
+
+                    final int posTo = switch (face) {
+                        case NORTH, SOUTH -> bx | (k << 4) | (by << 8);
+                        case WEST, EAST -> k | (by << 4) | (bx << 8);
+                        default -> bx | (by << 4) | (k << 8);
+                    };
+
+                    Section otherSection = chunk.getSection(neighborSection.blockY());
+
+                    final Block blockFrom = (switch (face) {
+                        case NORTH, SOUTH -> getBlock(otherSection.blockPalette(), bx, by, 15 - k);
+                        case WEST, EAST -> getBlock(otherSection.blockPalette(), 15 - k, bx, by);
+                        default -> getBlock(otherSection.blockPalette(), bx, 15 - k, by);
+                    });
+
+                    if (blocks == null) continue;
+                    Block blockTo = blocks[posTo];
+
+                    if (blockTo == null && blockFrom != null) {
+                        if (blockFrom.registry().collisionShape().isOccluded(Block.AIR.registry().collisionShape(), face.getOppositeFace()))
+                            continue;
+                    } else if (blockTo != null && blockFrom == null) {
+                        if (Block.AIR.registry().collisionShape().isOccluded(blockTo.registry().collisionShape(), face))
+                            continue;
+                    } else if (blockTo != null && blockFrom != null) {
+                        if (blockFrom.registry().collisionShape().isOccluded(blockTo.registry().collisionShape(), face.getOppositeFace()))
+                            continue;
+                    }
+
+                    if (lightEmission > 0) {
+                        final int index = posTo | (lightEmission << 12);
+                        lightSources.enqueue(index);
+                    }
+                }
+            }
+        }
+
+        return lightSources;
+    }
+
+    @Override
+    public void copyFrom(byte @NotNull [] array) {
+        if (array.length == 0) this.content = null;
+        else this.content = array.clone();
+    }
+
+    @Override
+    public Light calculateInternal(Instance instance, int chunkX, int sectionY, int chunkZ) {
+        Chunk chunk = instance.getChunk(chunkX, chunkZ);
+        if (chunk == null) {
+            this.toUpdateSet = Set.of();
+            return this;
+        }
+
+        this.isValidBorders = true;
+
+        Set<Point> toUpdate = new HashSet<>();
+
+        // Update single section with base lighting changes
+        Block[] blocks = new Block[SECTION_SIZE * SECTION_SIZE * SECTION_SIZE];
+        IntArrayFIFOQueue queue = buildInternalQueue(blockPalette, blocks);
+
+        Result result = LightCompute.compute(blocks, queue);
+        this.content = result.light();
+        this.borders = result.borders();
+
+        // Propagate changes to neighbors and self
+        for (int i = -1; i <= 1; i++) {
+            for (int j = -1; j <= 1; j++) {
+                Chunk neighborChunk = instance.getChunk(chunkX + i, chunkZ + j);
+                if (neighborChunk == null) continue;
+
+                for (int k = -1; k <= 1; k++) {
+                    Vec neighborPos = new Vec(chunkX + i, sectionY + k, chunkZ + j);
+
+                    if (neighborPos.blockY() >= neighborChunk.getMinSection() && neighborPos.blockY() < neighborChunk.getMaxSection()) {
+                        toUpdate.add(new Vec(neighborChunk.getChunkX(), neighborPos.blockY(), neighborChunk.getChunkZ()));
+                        neighborChunk.getSection(neighborPos.blockY()).blockLight().invalidatePropagation();
+                    }
+                }
+            }
+        }
+
+        toUpdate.add(new Vec(chunk.getChunkX(), sectionY, chunk.getChunkZ()));
+        this.toUpdateSet = toUpdate;
+
+        return this;
+    }
+
+    @Override
+    public void invalidate() {
+        invalidatePropagation();
+    }
+
+    @Override
+    public boolean requiresUpdate() {
+        return !isValidBorders;
+    }
+
+    @Override
+    public void set(byte[] copyArray) {
+        this.content = copyArray.clone();
+    }
+
+    @Override
+    public boolean requiresSend() {
+        boolean res = needsSend;
+        needsSend = false;
+        return res;
+    }
+
+    private void clearCache() {
+        this.contentPropagation = null;
+        this.bordersPropagation = null;
+        isValidBorders = true;
+        needsSend = true;
+    }
+
+    @Override
+    public byte[] array() {
+        if (content == null) return new byte[0];
+        if (contentPropagation == null) return content;
+        var res = bake(contentPropagation, content);
+        if (res == emptyContent) return new byte[0];
+        return res;
+    }
+
+    private boolean compareBorders(byte[] a, byte[] b) {
+        if (b == null && a == null) return true;
+        if (b == null || a == null) return false;
+
+        if (a.length != b.length) return false;
+        for (int i = 0; i < a.length; i++) {
+            if (a[i] > b[i]) return false;
+        }
+        return true;
+    }
+
+    private Block[] blocks() {
+        Block[] blocks = new Block[SECTION_SIZE * SECTION_SIZE * SECTION_SIZE];
+
+        blockPalette.getAllPresent((x, y, z, stateId) -> {
+            final Block block = Block.fromStateId((short) stateId);
+            assert block != null;
+            final int index = x | (z << 4) | (y << 8);
+            blocks[index] = block;
+        });
+
+        return blocks;
+    }
+
+    @Override
+    public Light calculateExternal(Instance instance, Chunk chunk, int sectionY) {
+        if (!isValidBorders) clearCache();
+
+        Map<BlockFace, Point> neighbors = Light.getNeighbors(chunk, sectionY);
+
+        Block[] blocks = blocks();
+        IntArrayFIFOQueue queue = buildExternalQueue(instance, blocks, neighbors, borders);
+        LightCompute.Result result = LightCompute.compute(blocks, queue);
+
+        byte[] contentPropagationTemp = result.light();
+        byte[][] borderTemp = result.borders();
+
+        this.contentPropagationSwap = bake(contentPropagationSwap, contentPropagationTemp);
+        this.bordersPropagationSwap = combineBorders(bordersPropagation, borderTemp);
+
+        Set<Point> toUpdate = new HashSet<>();
+
+        // Propagate changes to neighbors and self
+        for (var entry : neighbors.entrySet()) {
+            var neighbor = entry.getValue();
+            var face = entry.getKey();
+
+            byte[] next = borderTemp[face.ordinal()];
+            byte[] current = getBorderPropagation(face);
+
+            if (!compareBorders(next, current)) {
+                toUpdate.add(neighbor);
+            }
+        }
+
+        this.toUpdateSet = toUpdate;
+        return this;
+    }
+
+    private byte[][] combineBorders(byte[][] b1, byte[][] b2) {
+        if (b1 == null) return b2;
+
+        byte[][] newBorder = new byte[FACES.length][];
+        Arrays.setAll(newBorder, i -> new byte[SIDE_LENGTH]);
+        for (int i = 0; i < FACES.length; i++) {
+            newBorder[i] = combineBorders(b1[i], b2[i]);
+        }
+        return newBorder;
+    }
+
+    private byte[] bake(byte[] content1, byte[] content2) {
+        if (content1 == null && content2 == null) return emptyContent;
+        if (content1 == emptyContent && content2 == emptyContent) return emptyContent;
+
+        if (content1 == null) return content2;
+        if (content2 == null) return content1;
+
+        byte[] lightMax = new byte[LIGHT_LENGTH];
+        for (int i = 0; i < content1.length; i++) {
+            // Lower
+            byte l1 = (byte) (content1[i] & 0x0F);
+            byte l2 = (byte) (content2[i] & 0x0F);
+
+            // Upper
+            byte u1 = (byte) ((content1[i] >> 4) & 0x0F);
+            byte u2 = (byte) ((content2[i] >> 4) & 0x0F);
+
+            byte lower = (byte) Math.max(l1, l2);
+            byte upper = (byte) Math.max(u1, u2);
+
+            lightMax[i] = (byte) (lower | (upper << 4));
+        }
+        return lightMax;
+    }
+
+    @Override
+    public byte[] getBorderPropagation(BlockFace face) {
+        if (!isValidBorders) clearCache();
+
+        if (borders == null && bordersPropagation == null) return new byte[SIDE_LENGTH];
+        if (borders == null) return bordersPropagation[face.ordinal()];
+        if (bordersPropagation == null) return borders[face.ordinal()];
+
+        return combineBorders(bordersPropagation[face.ordinal()], borders[face.ordinal()]);
+    }
+
+    @Override
+    public void invalidatePropagation() {
+        this.isValidBorders = false;
+        this.needsSend = false;
+        this.bordersPropagation = null;
+        this.contentPropagation = null;
+    }
+
+    @Override
+    public int getLevel(int x, int y, int z) {
+        var array = array();
+        int index = x | (z << 4) | (y << 8);
+        return LightCompute.getLight(array, index);
+    }
+
+    private byte[] combineBorders(byte[] b1, byte[] b2) {
+        byte[] newBorder = new byte[SIDE_LENGTH];
+        for (int i = 0; i < newBorder.length; i++) {
+            var previous = b2[i];
+            var current = b1[i];
+            newBorder[i] = (byte) Math.max(previous, current);
+        }
+        return newBorder;
+    }
+}

src/main/java/net/minestom/server/instance/light/Light.java

@@ -0,0 +1,78 @@
+package net.minestom.server.instance.light;
+
+import net.minestom.server.coordinate.Point;
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.Chunk;
+import net.minestom.server.instance.Instance;
+import net.minestom.server.instance.block.BlockFace;
+import net.minestom.server.instance.palette.Palette;
+import net.minestom.server.utils.Direction;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+public interface Light {
+    static Light sky(@NotNull Palette blockPalette) {
+        return new SkyLight(blockPalette);
+    }
+
+    static Light block(@NotNull Palette blockPalette) {
+        return new BlockLight(blockPalette);
+    }
+
+    boolean requiresSend();
+
+    @ApiStatus.Internal
+    byte[] array();
+
+    Set<Point> flip();
+
+    void copyFrom(byte @NotNull [] array);
+
+    @ApiStatus.Internal
+    Light calculateExternal(Instance instance, Chunk chunk, int sectionY);
+
+    @ApiStatus.Internal
+    byte[] getBorderPropagation(BlockFace oppositeFace);
+
+    @ApiStatus.Internal
+    void invalidatePropagation();
+
+    int getLevel(int x, int y, int z);
+
+    @ApiStatus.Internal
+    Light calculateInternal(Instance instance, int chunkX, int chunkY, int chunkZ);
+
+    void invalidate();
+
+    boolean requiresUpdate();
+
+    void set(byte[] copyArray);
+
+    @ApiStatus.Internal
+    static Map<BlockFace, Point> getNeighbors(Chunk chunk, int sectionY) {
+        int chunkX = chunk.getChunkX();
+        int chunkZ = chunk.getChunkZ();
+
+        Map<BlockFace, Point> links = new HashMap<>();
+
+        for (BlockFace face : BlockFace.values()) {
+            Direction direction = face.toDirection();
+            int x = chunkX + direction.normalX();
+            int z = chunkZ + direction.normalZ();
+            int y = sectionY + direction.normalY();
+
+            Chunk foundChunk = chunk.getInstance().getChunk(x, z);
+
+            if (foundChunk == null) continue;
+            if (y - foundChunk.getMinSection() > foundChunk.getMaxSection() || y - foundChunk.getMinSection() < 0) continue;
+
+            links.put(face, new Vec(foundChunk.getChunkX(), y, foundChunk.getChunkZ()));
+        }
+
+        return links;
+    }
+}

src/main/java/net/minestom/server/instance/light/LightCompute.java

@@ -0,0 +1,117 @@
+package net.minestom.server.instance.light;
+
+import it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.block.BlockFace;
+import net.minestom.server.instance.palette.Palette;
+import net.minestom.server.utils.Direction;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.LinkedList;
+import java.util.Objects;
+
+import static net.minestom.server.instance.light.BlockLight.buildInternalQueue;
+
+final class LightCompute {
+    static final BlockFace[] FACES = BlockFace.values();
+    static final int LIGHT_LENGTH = 16 * 16 * 16 / 2;
+    static final int SIDE_LENGTH = 16 * 16;
+    static final int SECTION_SIZE = 16;
+
+    private static final byte[][] emptyBorders = new byte[FACES.length][SIDE_LENGTH];
+    static final byte[] emptyContent = new byte[LIGHT_LENGTH];
+
+    static @NotNull Result compute(Palette blockPalette) {
+        Block[] blocks = new Block[4096];
+        return LightCompute.compute(blocks, buildInternalQueue(blockPalette, blocks));
+    }
+
+    static @NotNull Result compute(Block[] blocks, IntArrayFIFOQueue lightPre) {
+        if (lightPre.isEmpty()) {
+            return new Result(emptyContent, emptyBorders);
+        }
+
+        byte[][] borders = new byte[FACES.length][SIDE_LENGTH];
+        byte[] lightArray = new byte[LIGHT_LENGTH];
+
+        var lightSources = new LinkedList<Integer>();
+
+        while (!lightPre.isEmpty()) {
+            int index = lightPre.dequeueInt();
+
+            final int x = index & 15;
+            final int z = (index >> 4) & 15;
+            final int y = (index >> 8) & 15;
+            final int newLightLevel = (index >> 12) & 15;
+            final int newIndex = x | (z << 4) | (y << 8);
+
+            final int oldLightLevel = getLight(lightArray, newIndex);
+
+            if (oldLightLevel < newLightLevel) {
+                placeLight(lightArray, newIndex, newLightLevel);
+                lightSources.add(index);
+            }
+        }
+
+        while (!lightSources.isEmpty()) {
+            final int index = lightSources.poll();
+            final int x = index & 15;
+            final int z = (index >> 4) & 15;
+            final int y = (index >> 8) & 15;
+            final int lightLevel = (index >> 12) & 15;
+
+            for (BlockFace face : FACES) {
+                Direction dir = face.toDirection();
+                final int xO = x + dir.normalX();
+                final int yO = y + dir.normalY();
+                final int zO = z + dir.normalZ();
+                final byte newLightLevel = (byte) (lightLevel - 1);
+                // Handler border
+                if (xO < 0 || xO >= SECTION_SIZE || yO < 0 || yO >= SECTION_SIZE || zO < 0 || zO >= SECTION_SIZE) {
+                    final byte[] border = borders[face.ordinal()];
+                    final int borderIndex = switch (face) {
+                        case WEST, EAST -> y * SECTION_SIZE + z;
+                        case BOTTOM, TOP -> x * SECTION_SIZE + z;
+                        case NORTH, SOUTH -> x * SECTION_SIZE + y;
+                    };
+                    border[borderIndex] = newLightLevel;
+                    continue;
+                }
+                // Section
+                final int newIndex = xO | (zO << 4) | (yO << 8);
+                if (getLight(lightArray, newIndex) + 2 <= lightLevel) {
+                    final Block currentBlock = Objects.requireNonNullElse(blocks[x | (z << 4) | (y << 8)], Block.AIR);
+
+                    final Block propagatedBlock = Objects.requireNonNullElse(blocks[newIndex], Block.AIR);
+                    boolean airAir = currentBlock.isAir() && propagatedBlock.isAir();
+                    if (!airAir && currentBlock.registry().collisionShape().isOccluded(propagatedBlock.registry().collisionShape(), face)) continue;
+                    placeLight(lightArray, newIndex, newLightLevel);
+                    lightSources.add(newIndex | (newLightLevel << 12));
+                }
+            }
+        }
+        return new Result(lightArray, borders);
+    }
+
+    record Result(byte[] light, byte[][] borders) {
+        Result {
+            assert light.length == LIGHT_LENGTH : "Only 16x16x16 sections are supported: " + light.length;
+        }
+
+        public byte getLight(int x, int y, int z) {
+            return (byte) LightCompute.getLight(light, x | (z << 4) | (y << 8));
+        }
+    }
+
+    private static void placeLight(byte[] light, int index, int value) {
+        final int shift = (index & 1) << 2;
+        final int i = index >>> 1;
+        light[i] = (byte) ((light[i] & (0xF0 >>> shift)) | (value << shift));
+    }
+
+    static int getLight(byte[] light, int index) {
+        if (index >>> 1 >= light.length) return 0;
+        final int value = light[index >>> 1];
+        return ((value >>> ((index & 1) << 2)) & 0xF);
+    }
+}

src/main/java/net/minestom/server/instance/light/SkyLight.java

@@ -0,0 +1,398 @@
+package net.minestom.server.instance.light;
+
+import it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue;
+import net.minestom.server.coordinate.Point;
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.Chunk;
+import net.minestom.server.instance.Instance;
+import net.minestom.server.instance.LightingChunk;
+import net.minestom.server.instance.Section;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.block.BlockFace;
+import net.minestom.server.instance.palette.Palette;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import static net.minestom.server.instance.light.LightCompute.*;
+
+final class SkyLight implements Light {
+    private final Palette blockPalette;
+
+    private byte[] content;
+    private byte[] contentPropagation;
+    private byte[] contentPropagationSwap;
+
+    private byte[][] borders;
+    private byte[][] bordersPropagation;
+    private byte[][] bordersPropagationSwap;
+    private boolean isValidBorders = true;
+    private boolean needsSend = true;
+
+    private Set<Point> toUpdateSet = new HashSet<>();
+
+    private boolean fullyLit = false;
+    private static final byte[][] bordersFullyLit = new byte[6][SIDE_LENGTH];
+    private static final byte[] contentFullyLit = new byte[LIGHT_LENGTH];
+
+    static {
+        Arrays.fill(contentFullyLit, (byte) -1);
+        for (byte[] border : bordersFullyLit) {
+            Arrays.fill(border, (byte) 14);
+        }
+    }
+
+    SkyLight(Palette blockPalette) {
+        this.blockPalette = blockPalette;
+    }
+
+    @Override
+    public Set<Point> flip() {
+        if (this.bordersPropagationSwap != null)
+            this.bordersPropagation = this.bordersPropagationSwap;
+
+        if (this.contentPropagationSwap != null)
+            this.contentPropagation = this.contentPropagationSwap;
+
+        this.bordersPropagationSwap = null;
+        this.contentPropagationSwap = null;
+
+        if (toUpdateSet == null) return Set.of();
+        return toUpdateSet;
+    }
+
+    static IntArrayFIFOQueue buildInternalQueue(Chunk c, int sectionY) {
+        IntArrayFIFOQueue lightSources = new IntArrayFIFOQueue();
+
+        if (c instanceof LightingChunk lc) {
+            int[] heightmap = lc.calculateHeightMap();
+            int maxY = c.getInstance().getDimensionType().getMinY() + c.getInstance().getDimensionType().getHeight();
+            int sectionMaxY = (sectionY + 1) * 16 - 1;
+            int sectionMinY = sectionY * 16;
+
+            for (int x = 0; x < 16; x++) {
+                for (int z = 0; z < 16; z++) {
+                    int height = heightmap[z << 4 | x];
+
+                    for (int y = Math.min(sectionMaxY, maxY); y >= Math.max(height, sectionMinY); y--) {
+                        int index = x | (z << 4) | ((y % 16) << 8);
+                        lightSources.enqueue(index | (15 << 12));
+                    }
+                }
+            }
+        }
+
+        return lightSources;
+    }
+
+    private static Block getBlock(Palette palette, int x, int y, int z) {
+        return Block.fromStateId((short)palette.get(x, y, z));
+    }
+
+    private static IntArrayFIFOQueue buildExternalQueue(Instance instance, Block[] blocks, Map<BlockFace, Point> neighbors, byte[][] borders) {
+        IntArrayFIFOQueue lightSources = new IntArrayFIFOQueue();
+
+        for (BlockFace face : BlockFace.values()) {
+            Point neighborSection = neighbors.get(face);
+            if (neighborSection == null) continue;
+
+            Chunk chunk = instance.getChunk(neighborSection.blockX(), neighborSection.blockZ());
+            if (chunk == null) continue;
+
+            byte[] neighborFace = chunk.getSection(neighborSection.blockY()).skyLight().getBorderPropagation(face.getOppositeFace());
+            if (neighborFace == null) continue;
+
+            for (int bx = 0; bx < 16; bx++) {
+                for (int by = 0; by < 16; by++) {
+                    final int borderIndex = bx * SECTION_SIZE + by;
+                    byte lightEmission = neighborFace[borderIndex];
+
+                    if (borders != null && borders[face.ordinal()] != null) {
+                        final int internalEmission = borders[face.ordinal()][borderIndex];
+                        if (lightEmission <= internalEmission) continue;
+                    }
+
+                    if (borders != null && borders[face.ordinal()] != null) {
+                        final int internalEmission = borders[face.ordinal()][borderIndex];
+                        if (lightEmission <= internalEmission) continue;
+                    }
+                    final int k = switch (face) {
+                        case WEST, BOTTOM, NORTH -> 0;
+                        case EAST, TOP, SOUTH -> 15;
+                    };
+
+                    final int posTo = switch (face) {
+                        case NORTH, SOUTH -> bx | (k << 4) | (by << 8);
+                        case WEST, EAST -> k | (by << 4) | (bx << 8);
+                        default -> bx | (by << 4) | (k << 8);
+                    };
+
+                    Section otherSection = chunk.getSection(neighborSection.blockY());
+
+                    final Block blockFrom = (switch (face) {
+                        case NORTH, SOUTH -> getBlock(otherSection.blockPalette(), bx, by, 15 - k);
+                        case WEST, EAST -> getBlock(otherSection.blockPalette(), 15 - k, bx, by);
+                        default -> getBlock(otherSection.blockPalette(), bx, 15 - k, by);
+                    });
+
+                    if (blocks == null) continue;
+                    Block blockTo = blocks[posTo];
+
+                    if (blockTo == null && blockFrom != null) {
+                        if (blockFrom.registry().collisionShape().isOccluded(Block.AIR.registry().collisionShape(), face.getOppositeFace()))
+                            continue;
+                    } else if (blockTo != null && blockFrom == null) {
+                        if (Block.AIR.registry().collisionShape().isOccluded(blockTo.registry().collisionShape(), face))
+                            continue;
+                    } else if (blockTo != null && blockFrom != null) {
+                        if (blockFrom.registry().collisionShape().isOccluded(blockTo.registry().collisionShape(), face.getOppositeFace()))
+                            continue;
+                    }
+
+                    final int index = posTo | (lightEmission << 12);
+
+                    if (lightEmission > 0) {
+                        lightSources.enqueue(index);
+                    }
+                }
+            }
+        }
+
+        return lightSources;
+    }
+
+    @Override
+    public void copyFrom(byte @NotNull [] array) {
+        if (array.length == 0) this.content = null;
+        else this.content = array.clone();
+    }
+
+    @Override
+    public Light calculateInternal(Instance instance, int chunkX, int sectionY, int chunkZ) {
+        Chunk chunk = instance.getChunk(chunkX, chunkZ);
+        this.isValidBorders = true;
+
+        // Update single section with base lighting changes
+        Block[] blocks = blocks();
+
+        int queueSize = SECTION_SIZE * SECTION_SIZE * SECTION_SIZE;
+        IntArrayFIFOQueue queue = new IntArrayFIFOQueue(0);
+        if (!fullyLit) {
+            queue = buildInternalQueue(chunk, sectionY);
+            queueSize = queue.size();
+        }
+
+        if (queueSize == SECTION_SIZE * SECTION_SIZE * SECTION_SIZE) {
+            this.fullyLit = true;
+            this.content = contentFullyLit;
+            this.borders = bordersFullyLit;
+        } else {
+            Result result = LightCompute.compute(blocks, queue);
+            this.content = result.light();
+            this.borders = result.borders();
+        }
+
+        Set<Point> toUpdate = new HashSet<>();
+
+        // Propagate changes to neighbors and self
+        for (int i = -1; i <= 1; i++) {
+            for (int j = -1; j <= 1; j++) {
+                Chunk neighborChunk = instance.getChunk(chunkX + i, chunkZ + j);
+                if (neighborChunk == null) continue;
+
+                for (int k = -1; k <= 1; k++) {
+                    Vec neighborPos = new Vec(chunkX + i, sectionY + k, chunkZ + j);
+
+                    if (neighborPos.blockY() >= neighborChunk.getMinSection() && neighborPos.blockY() < neighborChunk.getMaxSection()) {
+                        toUpdate.add(new Vec(neighborChunk.getChunkX(), neighborPos.blockY(), neighborChunk.getChunkZ()));
+                        neighborChunk.getSection(neighborPos.blockY()).skyLight().invalidatePropagation();
+                    }
+                }
+            }
+        }
+
+        toUpdate.add(new Vec(chunk.getChunkX(), sectionY, chunk.getChunkZ()));
+        this.toUpdateSet = toUpdate;
+
+        return this;
+    }
+
+    @Override
+    public void invalidate() {
+        invalidatePropagation();
+    }
+
+    @Override
+    public boolean requiresUpdate() {
+        return !isValidBorders;
+    }
+
+    @Override
+    public void set(byte[] copyArray) {
+        this.content = copyArray.clone();
+    }
+
+    @Override
+    public boolean requiresSend() {
+        boolean res = needsSend;
+        needsSend = false;
+        return res;
+    }
+
+    private void clearCache() {
+        this.contentPropagation = null;
+        this.bordersPropagation = null;
+        isValidBorders = true;
+        needsSend = true;
+        fullyLit = false;
+    }
+
+    @Override
+    public byte[] array() {
+        if (content == null) return new byte[0];
+        if (contentPropagation == null) return content;
+        var res = bake(contentPropagation, content);
+        if (res == emptyContent) return new byte[0];
+        return res;
+    }
+
+    private boolean compareBorders(byte[] a, byte[] b) {
+        if (b == null && a == null) return true;
+        if (b == null || a == null) return false;
+
+        if (a.length != b.length) return false;
+        for (int i = 0; i < a.length; i++) {
+            if (a[i] > b[i]) return false;
+        }
+        return true;
+    }
+
+    private Block[] blocks() {
+        Block[] blocks = new Block[SECTION_SIZE * SECTION_SIZE * SECTION_SIZE];
+
+        blockPalette.getAllPresent((x, y, z, stateId) -> {
+            final Block block = Block.fromStateId((short) stateId);
+            assert block != null;
+            final int index = x | (z << 4) | (y << 8);
+            blocks[index] = block;
+        });
+
+        return blocks;
+    }
+
+    @Override
+    public Light calculateExternal(Instance instance, Chunk chunk, int sectionY) {
+        if (!isValidBorders) clearCache();
+
+        Map<BlockFace, Point> neighbors = Light.getNeighbors(chunk, sectionY);
+        Set<Point> toUpdate = new HashSet<>();
+
+        Block[] blocks = blocks();
+        IntArrayFIFOQueue queue;
+
+        byte[][] borderTemp = bordersFullyLit;
+        if (!fullyLit) {
+            queue = buildExternalQueue(instance, blocks, neighbors, borders);
+            LightCompute.Result result = LightCompute.compute(blocks, queue);
+
+            byte[] contentPropagationTemp = result.light();
+            borderTemp = result.borders();
+            this.contentPropagationSwap = bake(contentPropagationSwap, contentPropagationTemp);
+            this.bordersPropagationSwap = combineBorders(bordersPropagation, borderTemp);
+        } else {
+            this.contentPropagationSwap = null;
+            this.bordersPropagationSwap = null;
+        }
+
+        // Propagate changes to neighbors and self
+        for (var entry : neighbors.entrySet()) {
+            var neighbor = entry.getValue();
+            var face = entry.getKey();
+
+            byte[] next = borderTemp[face.ordinal()];
+            byte[] current = getBorderPropagation(face);
+
+            if (!compareBorders(next, current)) {
+                toUpdate.add(neighbor);
+            }
+        }
+
+        this.toUpdateSet = toUpdate;
+        return this;
+    }
+
+    private byte[][] combineBorders(byte[][] b1, byte[][] b2) {
+        if (b1 == null) return b2;
+
+        byte[][] newBorder = new byte[FACES.length][];
+        Arrays.setAll(newBorder, i -> new byte[SIDE_LENGTH]);
+        for (int i = 0; i < FACES.length; i++) {
+            newBorder[i] = combineBorders(b1[i], b2[i]);
+        }
+        return newBorder;
+    }
+
+    private byte[] bake(byte[] content1, byte[] content2) {
+        if (content1 == null && content2 == null) return emptyContent;
+        if (content1 == emptyContent && content2 == emptyContent) return emptyContent;
+
+        if (content1 == null) return content2;
+        if (content2 == null) return content1;
+
+        byte[] lightMax = new byte[LIGHT_LENGTH];
+        for (int i = 0; i < content1.length; i++) {
+            // Lower
+            byte l1 = (byte) (content1[i] & 0x0F);
+            byte l2 = (byte) (content2[i] & 0x0F);
+
+            // Upper
+            byte u1 = (byte) ((content1[i] >> 4) & 0x0F);
+            byte u2 = (byte) ((content2[i] >> 4) & 0x0F);
+
+            byte lower = (byte) Math.max(l1, l2);
+            byte upper = (byte) Math.max(u1, u2);
+
+            lightMax[i] = (byte) (lower | (upper << 4));
+        }
+        return lightMax;
+    }
+
+    @Override
+    public byte[] getBorderPropagation(BlockFace face) {
+        if (!isValidBorders) clearCache();
+
+        if (borders == null && bordersPropagation == null) return new byte[SIDE_LENGTH];
+        if (borders == null) return bordersPropagation[face.ordinal()];
+        if (bordersPropagation == null) return borders[face.ordinal()];
+
+        return combineBorders(bordersPropagation[face.ordinal()], borders[face.ordinal()]);
+    }
+
+    @Override
+    public void invalidatePropagation() {
+        this.isValidBorders = false;
+        this.needsSend = false;
+        this.bordersPropagation = null;
+        this.contentPropagation = null;
+    }
+
+    @Override
+    public int getLevel(int x, int y, int z) {
+        var array = array();
+        int index = x | (z << 4) | (y << 8);
+        return LightCompute.getLight(array, index);
+    }
+
+    private byte[] combineBorders(byte[] b1, byte[] b2) {
+        byte[] newBorder = new byte[SIDE_LENGTH];
+        for (int i = 0; i < newBorder.length; i++) {
+            var previous = b2[i];
+            var current = b1[i];
+            newBorder[i] = (byte) Math.max(previous, current);
+        }
+        return newBorder;
+    }
+}

src/main/java/net/minestom/server/registry/Registry.java

@@ -170,6 +170,8 @@ public final class Registry {
         private final boolean air;
         private final boolean solid;
         private final boolean liquid;
+        private final boolean occludes;
+        private final int lightEmission;
         private final String blockEntity;
         private final int blockEntityId;
         private final Supplier<Material> materialSupplier;
@@ -189,7 +191,9 @@ public final class Registry {
             this.jumpFactor = main.getDouble("jumpFactor", 1);
             this.air = main.getBoolean("air", false);
             this.solid = main.getBoolean("solid");
+            this.occludes = main.getBoolean("occludes", true);
             this.liquid = main.getBoolean("liquid", false);
+            this.lightEmission = main.getInt("lightEmission", 0);
             {
                 Properties blockEntity = main.section("blockEntity");
                 if (blockEntity != null) {
@@ -205,8 +209,9 @@ public final class Registry {
                 this.materialSupplier = materialNamespace != null ? () -> Material.fromNamespaceId(materialNamespace) : () -> null;
             }
             {
-                final String string = main.getString("collisionShape");
-                this.shape = CollisionUtils.parseBlockShape(string, this);
+                final String collision = main.getString("collisionShape");
+                final String occlusion = main.getString("occlusionShape");
+                this.shape = CollisionUtils.parseBlockShape(collision, occlusion, this);
             }
         }
 
@@ -254,10 +259,18 @@ public final class Registry {
             return solid;
         }
 
+        public boolean occludes() {
+            return occludes;
+        }
+
         public boolean isLiquid() {
             return liquid;
         }
 
+        public int lightEmission() {
+            return lightEmission;
+        }
+
         public boolean isBlockEntity() {
             return blockEntity != null;
         }

src/test/java/net/minestom/server/instance/BlockLightMergeIntegrationTest.java

@@ -0,0 +1,564 @@
+package net.minestom.server.instance;
+
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.block.Block;
+import net.minestom.testing.Env;
+import net.minestom.testing.EnvTest;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static java.util.Map.entry;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+@EnvTest
+public class BlockLightMergeIntegrationTest {
+    @Test
+    public void testPropagationAir(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(8, 100,8 , Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = new HashMap<>();
+        for (int y = -15; y <= 15; ++y) {
+            expectedLights.put(new Vec(8, 100 + y, 8), Math.max(0, 14 - Math.abs(y)));
+        }
+
+        LightingChunk.relightSection(instance, 0, 6, 0);
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testTorch(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        instance.setGenerator(unit -> {
+            unit.modifier().fillHeight(39, 40, Block.STONE);
+            unit.modifier().fillHeight(50, 51, Block.STONE);
+        });
+
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(1, 40,1 , Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(2, 40, 2), 12)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testTorch2(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(1, 40,1 , Block.TORCH);
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(2, 40, 2), 12)
+        );
+        LightingChunk.relightSection(instance, 1, 2, 1);
+        assertLightInstance(instance, expectedLights);
+
+        instance.setBlock(-2, 40,-2, Block.TORCH);
+        expectedLights = Map.ofEntries(
+                entry(new Vec(2, 40, 2), 12)
+        );
+        LightingChunk.relightSection(instance, -1, 2, -1);
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testPropagationAir2(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(4, 60,8 , Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = new HashMap<>();
+        for (int y = -15; y <= 15; ++y) {
+            expectedLights.put(new Vec(8, 60 + y, 8), Math.max(0, 10 - Math.abs(y)));
+        }
+        for (int y = -15; y <= 15; ++y) {
+            expectedLights.put(new Vec(-2, 60 + y, 8), Math.max(0, 8 - Math.abs(y)));
+        }
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testPropagationAirRemoval(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(4, 100,8 , Block.TORCH);
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        instance.setBlock(4, 100,8 , Block.AIR);
+
+        Map<Vec, Integer> expectedLights = new HashMap<>();
+        for (int y = -15; y <= 15; ++y) {
+            expectedLights.put(new Vec(8, 100 + y, 8), 0);
+        }
+        for (int y = -15; y <= 15; ++y) {
+            expectedLights.put(new Vec(-2, 100 + y, 8), 0);
+        }
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBorderOcclusion(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(-1, 40, 4, Block.MAGMA_BLOCK);
+        instance.setBlock(-1, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 4, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-1, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 41, 4, Block.STONE);
+        instance.setBlock(-2, 40, 4, Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 42, 4), 0),
+                entry(new Vec(-2, 42, 3), 1),
+                entry(new Vec(-2, 41, 3), 2),
+                entry(new Vec(0, 40, 4), 2)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBorderOcclusion2(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(-1, 41, 4, Block.MAGMA_BLOCK);
+        instance.setBlock(-1, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 4, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-1, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 41, 4, Block.STONE);
+        instance.setBlock(-2, 40, 4, Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 42, 4), 8),
+                entry(new Vec(-2, 40, 2), 8),
+                entry(new Vec(-4, 40, 4), 4)
+
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBorderOcclusion3(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(0, 40, 8, Block.STONE);
+        instance.setBlock(1, 40, 8, Block.STONE);
+        instance.setBlock(0, 41, 7, Block.STONE);
+        instance.setBlock(1, 41, 7, Block.STONE);
+        instance.setBlock(2, 40, 7, Block.STONE);
+        instance.setBlock(1, 40, 6, Block.STONE);
+        instance.setBlock(0, 40, 6, Block.STONE);
+
+        instance.setBlock(1, 40, 7, Block.TORCH);
+        instance.setBlock(0, 40, 7, Block.SANDSTONE_SLAB.withProperty("type", "bottom"));
+        instance.setBlock(-1, 40, 7, Block.SANDSTONE_SLAB.withProperty("type", "top"));
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 40, 7), 0)
+
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBorderCrossing(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        for (int x = -2; x <= 1; ++x) {
+            for (int z = 5; z <= 20; ++z) {
+                instance.setBlock(x, 42, z, Block.STONE);
+            }
+        }
+
+        for (int z = 5; z <= 20; ++z) {
+            for (int y = 40; y <= 42; ++y) {
+                instance.setBlock(1, y, z, Block.STONE);
+                instance.setBlock(-2, y, z, Block.STONE);
+            }
+        }
+
+        for (int y = 40; y <= 42; ++y) {
+            instance.setBlock(-1, y, 6, Block.STONE);
+            instance.setBlock(0, y, 8, Block.STONE);
+            instance.setBlock(-1, y, 10, Block.STONE);
+            instance.setBlock(0, y, 12, Block.STONE);
+            instance.setBlock(-1, y, 14, Block.STONE);
+            instance.setBlock(0, y, 16, Block.STONE);
+            instance.setBlock(-1, y, 18, Block.STONE);
+            instance.setBlock(0, y, 20, Block.STONE);
+        }
+
+        instance.setBlock(-1, 40, 11, Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(-1, 40, 19), 2),
+                entry(new Vec(0, 40, 19), 3),
+                entry(new Vec(-1, 40, 16), 7),
+                entry(new Vec(-1, 40, 13), 12),
+                entry(new Vec(-1, 40, 7), 8),
+                entry(new Vec(-3, 40, 4), 1),
+                entry(new Vec(-3, 40, 5), 0),
+                entry(new Vec(-1, 40, 20), 1)
+
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBorderOcclusionRemoval(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(-1, 41, 4, Block.MAGMA_BLOCK);
+        instance.setBlock(-1, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 3, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 4, Block.MAGMA_BLOCK);
+        instance.setBlock(-3, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-1, 40, 5, Block.MAGMA_BLOCK);
+        instance.setBlock(-2, 41, 4, Block.STONE);
+
+
+        instance.setBlock(-2, 40, 4, Block.TORCH);
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        instance.setBlock(-2, 40, 4, Block.STONE);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 42, 4), 1),
+                entry(new Vec(-2, 40, 2), 2),
+                entry(new Vec(-4, 40, 4), 2)
+
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void chunkIntersection(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = 4; x <= 7; x++) {
+            for (int z = 6; z <= 8; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(94, -35, 128, Block.GLOW_LICHEN.withProperties(Map.of("west", "true")));
+
+        LightingChunk.relight(instance, instance.getChunks());
+
+        var val = instance.getChunk(5, 8).getSection(-2).blockLight().getLevel(14, 0, 0);
+        assertEquals(4, val);
+
+        var val2 = instance.getChunk(5, 8).getSection(-3).blockLight().getLevel(14, 15, 0);
+        assertEquals(5, val2);
+    }
+
+    @Test
+    public void skylight(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = 4; x <= 7; x++) {
+            for (int z = 6; z <= 8; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(94, 50, 128, Block.STONE);
+
+        LightingChunk.relight(instance, instance.getChunks());
+
+        var val = lightValSky(instance, new Vec(94, 41, 128));
+        assertEquals(14, val);
+    }
+
+    @Test
+    public void skylightContained(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = 4; x <= 7; x++) {
+            for (int z = 6; z <= 8; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(94, 50, 128, Block.STONE);
+        instance.setBlock(94, 52, 128, Block.STONE);
+
+        instance.setBlock(94, 51, 127, Block.STONE);
+        instance.setBlock(94, 51, 129, Block.STONE);
+        instance.setBlock(93, 51, 128, Block.STONE);
+        instance.setBlock(95, 51, 128, Block.STONE);
+
+        LightingChunk.relight(instance, instance.getChunks());
+
+        var val = lightValSky(instance, new Vec(94, 51, 128));
+        var val2 = lightValSky(instance, new Vec(94, 52, 128));
+        assertEquals(0, val2);
+        assertEquals(0, val);
+    }
+
+    @Test
+    public void testDiagonalRemoval(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(-2, 40, 14, Block.TORCH);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 40, 14), 14),
+                entry(new Vec(-2, 40, 18), 10),
+                entry(new Vec(2, 40, 18), 6)
+
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+        assertLightInstance(instance, expectedLights);
+
+        instance.setBlock(-2, 40, 14, Block.AIR);
+
+        expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 40, 14), 0),
+                entry(new Vec(-2, 40, 18), 0),
+                entry(new Vec(2, 40, 18), 0)
+
+        );
+        LightingChunk.relightSection(instance, 0, 2, 0);
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testDiagonalRemoval2(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(1, 40, 1, Block.TORCH);
+        instance.setBlock(1, 40, 17, Block.TORCH);
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        instance.setBlock(1, 40, 17, Block.AIR);
+
+        var expectedLights = Map.ofEntries(
+                entry(new Vec(-3, 40, 2), 9)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testDouble(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(-2, 40, 14, Block.TORCH);
+        instance.setBlock(1, 40, 27, Block.TORCH);
+
+        var expectedLights = Map.ofEntries(
+                entry(new Vec(-4, 40, 25), 7),
+                entry(new Vec(-4, 40, 18), 8)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+
+        instance.setBlock(-2, 40, 14, Block.AIR);
+
+        expectedLights = Map.ofEntries(
+                entry(new Vec(-4, 40, 25), 7),
+                entry(new Vec(-4, 40, 18), 0)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBlockRemoval(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        instance.setBlock(0, 40, 0, Block.STONE);
+        instance.setBlock(1, 40, -1, Block.STONE);
+        instance.setBlock(0, 40, -2, Block.STONE);
+        instance.setBlock(-1, 40, -1, Block.STONE);
+        instance.setBlock(0, 41, -1, Block.STONE);
+        instance.setBlock(0, 40, -1, Block.GLOWSTONE);
+
+        var expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 40, -1), 0)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+
+        instance.setBlock(-1, 40, -1, Block.AIR);
+
+        expectedLights = Map.ofEntries(
+                entry(new Vec(-2, 40, -1), 13)
+        );
+
+        LightingChunk.relightSection(instance, 0, 2, 0);
+
+        assertLightInstance(instance, expectedLights);
+    }
+
+    static byte lightVal(Instance instance, Vec pos) {
+        final Vec modPos = new Vec(((pos.blockX() % 16) + 16) % 16, ((pos.blockY() % 16) + 16) % 16, ((pos.blockZ() % 16) + 16) % 16);
+        Chunk chunk = instance.getChunkAt(pos.blockX(), pos.blockZ());
+        return (byte) chunk.getSectionAt(pos.blockY()).blockLight().getLevel(modPos.blockX(), modPos.blockY(), modPos.blockZ());
+    }
+
+    static byte lightValSky(Instance instance, Vec pos) {
+        final Vec modPos = new Vec(((pos.blockX() % 16) + 16) % 16, ((pos.blockY() % 16) + 16) % 16, ((pos.blockZ() % 16) + 16) % 16);
+        Chunk chunk = instance.getChunkAt(pos.blockX(), pos.blockZ());
+        return (byte) chunk.getSectionAt(pos.blockY()).skyLight().getLevel(modPos.blockX(), modPos.blockY(), modPos.blockZ());
+    }
+
+    public static void assertLightInstance(Instance instance, Map<Vec, Integer> expectedLights) {
+        List<String> errors = new ArrayList<>();
+        for (var entry : expectedLights.entrySet()) {
+            final Integer expected = entry.getValue();
+            final Vec pos = entry.getKey();
+
+            final byte light = lightVal(instance, pos);
+
+            if (light != expected) {
+                String errorLine = String.format("Expected %d at [%d,%d,%d] but got %d", expected, pos.blockX(), pos.blockY(), pos.blockZ(), light);
+                System.err.println();
+                errors.add(errorLine);
+            }
+        }
+        if (!errors.isEmpty()) {
+            StringBuilder sb = new StringBuilder();
+            for (String s : errors) {
+                sb.append(s).append("\n");
+            }
+            System.err.println(sb);
+            fail();
+        }
+    }
+}

src/test/java/net/minestom/server/instance/light/BlockIsOccludedTest.java

@@ -0,0 +1,204 @@
+package net.minestom.server.instance.light;
+
+import net.minestom.server.collision.Shape;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.block.BlockFace;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class BlockIsOccludedTest {
+    @Test
+    public void blockAir() {
+        Shape airBlock = Block.AIR.registry().collisionShape();
+        
+        for (BlockFace face : BlockFace.values()) {
+            assertFalse(airBlock.isOccluded(airBlock, face));
+        }
+    }
+
+    @Test
+    public void blockLantern() {
+        Shape shape = Block.LANTERN.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        for (BlockFace face : BlockFace.values()) {
+            assertFalse(shape.isOccluded(airBlock, face));
+        }
+    }
+
+    @Test
+    public void blockSpruceLeaves() {
+        Shape shape = Block.SPRUCE_LEAVES.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        for (BlockFace face : BlockFace.values()) {
+            assertFalse(shape.isOccluded(airBlock, face));
+        }
+    }
+
+    @Test
+    public void blockCauldron() {
+        Shape shape = Block.CAULDRON.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        for (BlockFace face : BlockFace.values()) {
+            assertFalse(shape.isOccluded(airBlock, face));
+        }
+    }
+
+    @Test
+    public void blockSlabBottomAir() {
+        Shape shape = Block.SANDSTONE_SLAB.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        assertTrue(shape.isOccluded(airBlock, BlockFace.BOTTOM));
+
+        assertFalse(shape.isOccluded(airBlock, BlockFace.NORTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.SOUTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.EAST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.WEST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.TOP));
+    }
+
+    @Test
+    public void blockSlabTopEnchantingTable() {
+        Shape shape1 = Block.SANDSTONE_SLAB.withProperty("type", "top").registry().collisionShape();
+        Shape shape2 = Block.ENCHANTING_TABLE.registry().collisionShape();
+
+        assertFalse(shape1.isOccluded(shape2, BlockFace.BOTTOM));
+
+        assertTrue(shape1.isOccluded(shape2, BlockFace.NORTH));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.SOUTH));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.EAST));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.WEST));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.TOP));
+    }
+
+    @Test
+    public void blockStairWest() {
+        Shape shape = Block.SANDSTONE_STAIRS.withProperties(Map.of(
+                "facing", "west",
+                "half", "bottom",
+                "shape", "straight")).registry().collisionShape();
+
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        assertTrue(shape.isOccluded(airBlock, BlockFace.WEST));
+        assertTrue(shape.isOccluded(airBlock, BlockFace.BOTTOM));
+
+        assertFalse(shape.isOccluded(airBlock, BlockFace.SOUTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.EAST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.NORTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.TOP));
+    }
+
+    @Test
+    public void blockSlabBottomStone() {
+        Shape shape = Block.SANDSTONE_SLAB.registry().collisionShape();
+        Shape stoneBlock = Block.STONE.registry().collisionShape();
+
+        assertTrue(shape.isOccluded(stoneBlock, BlockFace.BOTTOM));
+        assertTrue(shape.isOccluded(stoneBlock, BlockFace.NORTH));
+        assertTrue(shape.isOccluded(stoneBlock, BlockFace.SOUTH));
+        assertTrue(shape.isOccluded(stoneBlock, BlockFace.EAST));
+        assertTrue(shape.isOccluded(stoneBlock, BlockFace.WEST));
+        assertTrue(shape.isOccluded(stoneBlock, BlockFace.TOP));
+    }
+
+    @Test
+    public void blockStone() {
+        Shape shape = Block.STONE.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        for (BlockFace face : BlockFace.values()) {
+            assertTrue(shape.isOccluded(airBlock, face));
+        }
+    }
+
+    @Test
+    public void blockStair() {
+        Shape shape = Block.SANDSTONE_STAIRS.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        assertTrue(shape.isOccluded(airBlock, BlockFace.NORTH));
+        assertTrue(shape.isOccluded(airBlock, BlockFace.BOTTOM));
+
+        assertFalse(shape.isOccluded(airBlock, BlockFace.SOUTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.EAST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.WEST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.TOP));
+    }
+
+    @Test
+    public void blockSlab() {
+        Shape shape = Block.SANDSTONE_SLAB.registry().collisionShape();
+        Shape airBlock = Block.AIR.registry().collisionShape();
+
+        assertTrue(shape.isOccluded(airBlock, BlockFace.BOTTOM));
+
+        assertFalse(shape.isOccluded(airBlock, BlockFace.NORTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.SOUTH));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.EAST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.WEST));
+        assertFalse(shape.isOccluded(airBlock, BlockFace.TOP));
+    }
+
+    @Test
+    public void blockSlabBottomAndSlabTop() {
+        Shape shape1 = Block.SANDSTONE_SLAB.registry().collisionShape();
+        Shape shape2 = Block.SANDSTONE_SLAB.withProperty("type", "top").registry().collisionShape();
+
+        assertFalse(shape1.isOccluded(shape2, BlockFace.TOP));
+
+        assertTrue(shape1.isOccluded(shape2, BlockFace.BOTTOM));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.EAST));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.WEST));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.NORTH));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.SOUTH));
+    }
+
+    @Test
+    public void blockSlabBottomAndSlabBottom() {
+        Shape shape = Block.SANDSTONE_SLAB.registry().collisionShape();
+
+        assertTrue(shape.isOccluded(shape, BlockFace.BOTTOM));
+        assertTrue(shape.isOccluded(shape, BlockFace.TOP));
+
+        assertFalse(shape.isOccluded(shape, BlockFace.EAST));
+        assertFalse(shape.isOccluded(shape, BlockFace.WEST));
+        assertFalse(shape.isOccluded(shape, BlockFace.NORTH));
+        assertFalse(shape.isOccluded(shape, BlockFace.SOUTH));
+    }
+
+    @Test
+    public void blockStairAndSlabBottom() {
+        Shape shape1 = Block.STONE_STAIRS.registry().collisionShape();
+        Shape shape2 = Block.SANDSTONE_SLAB.registry().collisionShape();
+
+        assertTrue(shape1.isOccluded(shape2, BlockFace.BOTTOM));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.NORTH));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.TOP));
+
+        assertFalse(shape1.isOccluded(shape2, BlockFace.EAST));
+        assertFalse(shape1.isOccluded(shape2, BlockFace.WEST));
+        assertFalse(shape1.isOccluded(shape2, BlockFace.SOUTH));
+    }
+
+    @Test
+    public void blockStairAndSlabTop() {
+        Shape shape1 = Block.STONE_STAIRS.registry().collisionShape();
+        Shape shape2 = Block.SANDSTONE_SLAB.withProperty("type", "top").registry().collisionShape();
+
+        assertTrue(shape1.isOccluded(shape2, BlockFace.NORTH));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.BOTTOM));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.EAST));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.WEST));
+        assertTrue(shape1.isOccluded(shape2, BlockFace.SOUTH));
+
+        assertFalse(shape1.isOccluded(shape2, BlockFace.TOP));
+    }
+}

src/test/java/net/minestom/server/instance/light/BlockLightTest.java

@@ -0,0 +1,239 @@
+package net.minestom.server.instance.light;
+
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.palette.Palette;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static java.util.Map.entry;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+public class BlockLightTest {
+
+    @Test
+    public void empty() {
+        var palette = Palette.blocks();
+        var result = LightCompute.compute(palette);
+        for (byte light : result.light()) {
+            assertEquals(0, light);
+        }
+    }
+
+    @Test
+    public void glowstone() {
+        var palette = Palette.blocks();
+        palette.set(0, 1, 0, Block.GLOWSTONE.stateId());
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.of(
+                new Vec(0, 1, 0), 15,
+                new Vec(0, 1, 1), 14,
+                new Vec(0, 1, 2), 13));
+    }
+
+    @Test
+    public void doubleGlowstone() {
+        var palette = Palette.blocks();
+        palette.set(0, 1, 0, Block.GLOWSTONE.stateId());
+        palette.set(4, 1, 4, Block.GLOWSTONE.stateId());
+
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.of(
+                new Vec(1, 1, 3), 11,
+                new Vec(3, 3, 7), 9,
+                new Vec(1, 1, 1), 13,
+                new Vec(3, 1, 4), 14));
+    }
+
+    @Test
+    public void glowstoneBorder() {
+        var palette = Palette.blocks();
+        palette.set(0, 1, 0, Block.GLOWSTONE.stateId());
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.of(
+                // X axis
+                new Vec(-1, 0, 0), 13,
+                new Vec(-1, 1, 0), 14,
+                new Vec(-1, 2, 0), 13,
+                new Vec(-1, 3, 0), 12,
+                // Z axis
+                new Vec(0, 0, -1), 13,
+                new Vec(0, 1, -1), 14,
+                new Vec(0, 2, -1), 13,
+                new Vec(0, 3, -1), 12));
+    }
+
+    @Test
+    public void glowstoneBlock() {
+        var palette = Palette.blocks();
+        palette.set(0, 1, 0, Block.GLOWSTONE.stateId());
+        palette.set(0, 1, 1, Block.STONE.stateId());
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.of(
+                new Vec(0, 1, 0), 15,
+                new Vec(0, 1, 1), 0,
+                new Vec(0, 1, 2), 11));
+    }
+
+    @Test
+    public void isolated() {
+        var palette = Palette.blocks();
+        palette.set(4, 1, 4, Block.GLOWSTONE.stateId());
+
+        palette.set(3, 1, 4, Block.STONE.stateId());
+        palette.set(4, 1, 5, Block.STONE.stateId());
+        palette.set(4, 1, 3, Block.STONE.stateId());
+        palette.set(5, 1, 4, Block.STONE.stateId());
+        palette.set(4, 2, 4, Block.STONE.stateId());
+        palette.set(4, 0, 4, Block.STONE.stateId());
+
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.ofEntries(
+                // Glowstone
+                entry(new Vec(4, 1, 4), 15),
+                // Isolation
+                entry(new Vec(3, 1, 4), 0),
+                entry(new Vec(4, 1, 5), 0),
+                entry(new Vec(4, 1, 3), 0),
+                entry(new Vec(5, 1, 4), 0),
+                entry(new Vec(4, 2, 4), 0),
+                entry(new Vec(4, 0, 4), 0),
+                // Outside location
+                entry(new Vec(2, 2, 3), 0)));
+    }
+
+    @Test
+    public void isolatedStair() {
+        var palette = Palette.blocks();
+        palette.set(4, 1, 4, Block.GLOWSTONE.stateId());
+        palette.set(3, 1, 4, Block.OAK_STAIRS.withProperties(Map.of(
+                "facing", "east",
+                "half", "bottom",
+                "shape", "straight")).stateId());
+        palette.set(4, 1, 5, Block.STONE.stateId());
+        palette.set(4, 1, 3, Block.STONE.stateId());
+        palette.set(5, 1, 4, Block.STONE.stateId());
+        palette.set(4, 2, 4, Block.STONE.stateId());
+        palette.set(4, 0, 4, Block.STONE.stateId());
+
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.ofEntries(
+                // Glowstone
+                entry(new Vec(4, 1, 4), 15),
+                // Front of stair
+                entry(new Vec(2, 1, 4), 0)));
+    }
+
+    @Test
+    public void isolatedStairOpposite() {
+        var palette = Palette.blocks();
+        palette.set(4, 1, 4, Block.GLOWSTONE.stateId());
+        palette.set(3, 1, 4, Block.OAK_STAIRS.withProperties(Map.of(
+                "facing", "west",
+                "half", "bottom",
+                "shape", "straight")).stateId());
+        palette.set(4, 1, 5, Block.STONE.stateId());
+        palette.set(4, 1, 3, Block.STONE.stateId());
+        palette.set(5, 1, 4, Block.STONE.stateId());
+        palette.set(4, 2, 4, Block.STONE.stateId());
+        palette.set(4, 0, 4, Block.STONE.stateId());
+
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.ofEntries(
+                // Glowstone
+                entry(new Vec(4, 1, 4), 15),
+                // Stair
+                entry(new Vec(3, 1, 4), 14),
+                // Front of stair
+                entry(new Vec(2, 1, 4), 11),
+                // Others
+                entry(new Vec(3, 0, 5), 12),
+                entry(new Vec(3, 0, 3), 12)));
+    }
+
+    @Test
+    public void isolatedStairWest() {
+        var palette = Palette.blocks();
+        palette.set(4, 1, 4, Block.GLOWSTONE.stateId());
+        palette.set(3, 1, 4, Block.OAK_STAIRS.withProperties(Map.of(
+                "facing", "west",
+                "half", "bottom",
+                "shape", "straight")).stateId());
+        palette.set(4, 1, 5, Block.STONE.stateId());
+        palette.set(4, 1, 3, Block.STONE.stateId());
+        palette.set(5, 1, 4, Block.STONE.stateId());
+        palette.set(4, 2, 4, Block.STONE.stateId());
+        palette.set(4, 0, 4, Block.STONE.stateId());
+
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.ofEntries(
+                // Glowstone
+                entry(new Vec(4, 1, 4), 15),
+                // Stair
+                entry(new Vec(3, 1, 4), 14),
+                // Front of stair
+                entry(new Vec(2, 1, 4), 11),
+                // Others
+                entry(new Vec(3, 0, 5), 12),
+                entry(new Vec(3, 0, 3), 12),
+                entry(new Vec(3, 2, 4), 13),
+                entry(new Vec(3, -1, 4), 10),
+                entry(new Vec(2, 0, 4), 10)));
+    }
+
+    @Test
+    public void isolatedStairSouth() {
+        var palette = Palette.blocks();
+        palette.set(4, 1, 4, Block.GLOWSTONE.stateId());
+        palette.set(3, 1, 4, Block.OAK_STAIRS.withProperties(Map.of(
+                "facing", "south",
+                "half", "bottom",
+                "shape", "straight")).stateId());
+        palette.set(4, 1, 5, Block.STONE.stateId());
+        palette.set(4, 1, 3, Block.STONE.stateId());
+        palette.set(5, 1, 4, Block.STONE.stateId());
+        palette.set(4, 2, 4, Block.STONE.stateId());
+        palette.set(4, 0, 4, Block.STONE.stateId());
+
+        var result = LightCompute.compute(palette);
+        assertLight(result, Map.ofEntries(
+                // Glowstone
+                entry(new Vec(4, 1, 4), 15),
+                // Stair
+                entry(new Vec(3, 1, 4), 14),
+                // Front of stair
+                entry(new Vec(2, 1, 4), 13),
+                // Others
+                entry(new Vec(3, 0, 5), 10),
+                entry(new Vec(3, 0, 3), 12)));
+    }
+
+    void assertLight(LightCompute.Result result, Map<Vec, Integer> expectedLights) {
+        List<String> errors = new ArrayList<>();
+        for (int x = 0; x < 16; x++) {
+            for (int y = 0; y < 16; y++) {
+                for (int z = 0; z < 16; z++) {
+                    var expected = expectedLights.get(new Vec(x, y, z));
+                    if (expected != null) {
+                        final byte light = result.getLight(x, y, z);
+                        if (light != expected) {
+                            errors.add(String.format("Expected %d at [%d,%d,%d] but got %d", expected, x, y, z, light));
+                        }
+                    }
+                }
+            }
+        }
+        if (!errors.isEmpty()) {
+            StringBuilder sb = new StringBuilder();
+            for (String s : errors) {
+                sb.append(s).append("\n");
+            }
+            System.err.println(sb);
+            fail();
+        }
+    }
+}

src/test/java/net/minestom/server/instance/light/LightParityIntegrationTest.java

@@ -0,0 +1,164 @@
+package net.minestom.server.instance.light;
+
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.*;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.instance.palette.Palette;
+import net.minestom.testing.Env;
+import net.minestom.testing.EnvTest;
+import org.jglrxavpok.hephaistos.mca.AnvilException;
+import org.jglrxavpok.hephaistos.mca.BlockState;
+import org.jglrxavpok.hephaistos.mca.ChunkSection;
+import org.jglrxavpok.hephaistos.mca.RegionFile;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.Path;
+import java.util.*;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
+@EnvTest
+public class LightParityIntegrationTest {
+
+    @Test
+    public void test(Env env) throws URISyntaxException, IOException, AnvilException {
+        assumeTrue(false);
+
+        Map<Vec, SectionEntry> sections = retrieveSections();
+        // Generate our own light
+
+        InstanceContainer instance = (InstanceContainer) env.createFlatInstance();
+        instance.setChunkSupplier(LightingChunk::new);
+        instance.setChunkLoader(new AnvilLoader(Path.of("./src/test/resources/net/minestom/server/instance/lighting")));
+
+        int end = 4;
+        // Load the chunks
+        for (int x = 0; x < end; x++) {
+            for (int z = 0; z < end; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        LightingChunk.relight(instance, instance.getChunks());
+
+        int differences = 0;
+        int differencesZero = 0;
+        int blocks = 0;
+        int sky = 0;
+
+        for (Chunk chunk : instance.getChunks()) {
+            if (chunk.getChunkX() == 0 || chunk.getChunkZ() == 0) {
+                continue;
+            }
+
+            if (chunk.getChunkX() == end - 1 || chunk.getChunkZ() == end - 1) {
+                continue;
+            }
+
+            for (int sectionIndex = chunk.getMinSection(); sectionIndex < chunk.getMaxSection(); sectionIndex++) {
+                if (sectionIndex != 3) continue;
+
+                Section section = chunk.getSection(sectionIndex);
+
+                Light sectionLight = section.blockLight();
+                Light sectionSkyLight = section.skyLight();
+                SectionEntry sectionEntry = sections.get(new Vec(chunk.getChunkX(), sectionIndex, chunk.getChunkZ()));
+                if (sectionEntry == null) {
+                    continue;
+                }
+
+                byte[] serverBlock = sectionLight.array();
+                byte[] mcaBlock = sectionEntry.block;
+
+                byte[] serverSky = sectionSkyLight.array();
+                byte[] mcaSky = sectionEntry.sky;
+
+                for (int x = 0; x < 16; ++x) {
+                    for (int y = 0; y < 16; ++y) {
+                        for (int z = 0; z < 16; ++z) {
+                            int index = x | (z << 4) | (y << 8);
+
+                            {
+                                int serverBlockValue = LightCompute.getLight(serverBlock, index);
+                                int mcaBlockValue = mcaBlock.length == 0 ? 0 : LightCompute.getLight(mcaBlock, index);
+
+                                if (serverBlockValue != mcaBlockValue) {
+                                    if (serverBlockValue == 0) differencesZero++;
+                                    else differences++;
+                                    blocks++;
+                                }
+                            }
+
+                            {
+                                int serverSkyValue = LightCompute.getLight(serverSky, index);
+                                int mcaSkyValue = mcaSky.length == 0 ? 0 : LightCompute.getLight(mcaSky, index);
+
+                                if (serverSkyValue != mcaSkyValue) {
+                                    if (serverSkyValue == 0) differencesZero++;
+                                    else differences++;
+                                    sky++;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        assertEquals(0, differences);
+        assertEquals(0, differencesZero);
+        assertEquals(0, blocks);
+        assertEquals(0, sky);
+    }
+
+    record SectionEntry(Palette blocks, byte[] sky, byte[] block) {
+    }
+
+    private static Map<Vec, SectionEntry> retrieveSections() throws IOException, URISyntaxException, AnvilException {
+        URL defaultImage = LightParityIntegrationTest.class.getResource("/net/minestom/server/instance/lighting/region/r.0.0.mca");
+        assert defaultImage != null;
+        File imageFile = new File(defaultImage.toURI());
+        var regionFile = new RegionFile(new RandomAccessFile(imageFile, "rw"),
+                0, 0, -64, 384);
+
+        Map<Vec, SectionEntry> sections = new HashMap<>();
+        // Read from anvil
+        for (int x = 1; x < 3; x++) {
+            for (int z = 1; z < 3; z++) {
+                var chunk = regionFile.getChunk(x, z);
+                if (chunk == null) continue;
+
+                for (int yLevel = chunk.getMinY(); yLevel <= chunk.getMaxY(); yLevel += 16) {
+                    var section = chunk.getSection((byte) (yLevel/16));
+                    var palette = loadBlocks(section);
+                    var sky = section.getSkyLights();
+                    var block = section.getBlockLights();
+                    sections.put(new Vec(x, section.getY(), z), new SectionEntry(palette, sky, block));
+                }
+            }
+        }
+        return sections;
+    }
+
+    private static Palette loadBlocks(ChunkSection section) throws AnvilException {
+        var palette = Palette.blocks();
+        for (int x = 0; x < Chunk.CHUNK_SECTION_SIZE; x++) {
+            for (int z = 0; z < Chunk.CHUNK_SECTION_SIZE; z++) {
+                for (int y = 0; y < Chunk.CHUNK_SECTION_SIZE; y++) {
+                    final BlockState blockState = section.get(x, y, z);
+                    final String blockName = blockState.getName();
+                    Block block = Objects.requireNonNull(Block.fromNamespaceId(blockName))
+                            .withProperties(blockState.getProperties());
+                    palette.set(x, y, z, block.stateId());
+                }
+            }
+        }
+        return palette;
+    }
+}

src/test/java/net/minestom/server/instance/light/WorldRelightIntegrationTest.java

@@ -0,0 +1,67 @@
+package net.minestom.server.instance.light;
+
+import net.minestom.server.ServerProcess;
+import net.minestom.server.coordinate.Vec;
+import net.minestom.server.instance.Instance;
+import net.minestom.server.instance.LightingChunk;
+import net.minestom.server.instance.block.Block;
+import net.minestom.testing.Env;
+import net.minestom.testing.EnvTest;
+import org.jetbrains.annotations.NotNull;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+
+import static java.util.Map.entry;
+import static net.minestom.server.instance.BlockLightMergeIntegrationTest.assertLightInstance;
+
+@EnvTest
+public class WorldRelightIntegrationTest {
+    private @NotNull Instance createLightingInstance(@NotNull ServerProcess process) {
+        var instance = process.instance().createInstanceContainer();
+        instance.setGenerator(unit -> {
+            unit.modifier().fillHeight(39, 40, Block.STONE);
+            unit.subdivide().forEach(u -> u.modifier().setBlock(0, 10, 0, Block.GLOWSTONE));
+            unit.modifier().fillHeight(50, 51, Block.STONE);
+        });
+        return instance;
+    }
+
+    @Test
+    public void testBorderLava(Env env) {
+        Instance instance = env.createFlatInstance();
+        instance.loadChunk(6, 16).join();
+        instance.loadChunk(6, 15).join();
+
+        instance.setBlock(106, 70, 248, Block.LAVA);
+        instance.setBlock(106, 71, 249, Block.LAVA);
+
+        Map<Vec, Integer> expectedLights = Map.ofEntries(
+                entry(new Vec(105, 72, 256), 6)
+        );
+
+        LightingChunk.relight(instance, instance.getChunks());
+        assertLightInstance(instance, expectedLights);
+    }
+
+    @Test
+    public void testBlockRemoval(Env env) {
+        Instance instance = createLightingInstance(env.process());
+        for (int x = -3; x <= 3; x++) {
+            for (int z = -3; z <= 3; z++) {
+                instance.loadChunk(x, z).join();
+            }
+        }
+
+        LightingChunk.relight(instance, instance.getChunks());
+
+        var expectedLights = Map.ofEntries(
+                entry(new Vec(-1, 40, 0), 12),
+                entry(new Vec(-9, 40, 8), 0),
+                entry(new Vec(-1, 40, -16), 12),
+                entry(new Vec(-1, 37, 0), 3),
+                entry(new Vec(-8, 37, -8), 0)
+        );
+        assertLightInstance(instance, expectedLights);
+    }
+}