diff --git a/src/main/java/ru/windcorp/progressia/client/Client.java b/src/main/java/ru/windcorp/progressia/client/Client.java
index 9902de5..0d84fe3 100644
--- a/src/main/java/ru/windcorp/progressia/client/Client.java
+++ b/src/main/java/ru/windcorp/progressia/client/Client.java
@@ -19,7 +19,7 @@ public class Client {
 	private final ServerCommsChannel comms;
 	
 	public Client(WorldData world, ServerCommsChannel comms) {
-		this.world = new WorldRender(world);
+		this.world = new WorldRender(world, this);
 		this.comms = comms;
 		
 		comms.addListener(new DefaultClientCommsListener(this));
diff --git a/src/main/java/ru/windcorp/progressia/client/world/ChunkRender.java b/src/main/java/ru/windcorp/progressia/client/world/ChunkRender.java
index 94af7f8..5cf3555 100644
--- a/src/main/java/ru/windcorp/progressia/client/world/ChunkRender.java
+++ b/src/main/java/ru/windcorp/progressia/client/world/ChunkRender.java
@@ -59,7 +59,6 @@ implements GenericChunk<
 	private final WorldRender world;
 	private final ChunkData data;
 
-	private boolean needsUpdate;
 	private Model model = null;
 	
 	private final Map<TileDataStack, TileRenderStackImpl> tileRenderLists =
@@ -108,16 +107,12 @@ implements GenericChunk<
 	}
 	
 	public synchronized void markForUpdate() {
-		this.needsUpdate = true;
-	}
-	
-	public synchronized boolean needsUpdate() {
-		return needsUpdate;
+		getWorld().markChunkForUpdate(getPosition());
 	}
 	
 	public synchronized void render(ShapeRenderHelper renderer) {
-		if (model == null || needsUpdate()) {
-			buildModel();
+		if (model == null) {
+			return;
 		}
 		
 		renderer.pushTransform().translate(
@@ -131,7 +126,7 @@ implements GenericChunk<
 		renderer.popTransform();
 	}
 
-	private void buildModel() {
+	public synchronized void update() {
 		Collection<ChunkRenderOptimizer> optimizers =
 				ChunkRenderOptimizers.getAllSuppliers().stream()
 				.map(ChunkRenderOptimizerSupplier::createOptimizer)
@@ -159,7 +154,6 @@ implements GenericChunk<
 				.forEach(builder::addPart);
 		
 		model = new StaticModel(builder);
-		needsUpdate = false;
 	}
 
 	private void buildBlock(
diff --git a/src/main/java/ru/windcorp/progressia/client/world/WorldRender.java b/src/main/java/ru/windcorp/progressia/client/world/WorldRender.java
index 14f99d4..4b01aaf 100644
--- a/src/main/java/ru/windcorp/progressia/client/world/WorldRender.java
+++ b/src/main/java/ru/windcorp/progressia/client/world/WorldRender.java
@@ -20,10 +20,12 @@ package ru.windcorp.progressia.client.world;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.WeakHashMap;
 
 import glm.vec._3.i.Vec3i;
+import ru.windcorp.progressia.client.Client;
 import ru.windcorp.progressia.client.graphics.backend.FaceCulling;
 import ru.windcorp.progressia.client.graphics.model.ShapeRenderHelper;
 import ru.windcorp.progressia.client.world.block.BlockRender;
@@ -31,11 +33,14 @@ import ru.windcorp.progressia.client.world.entity.EntityRenderRegistry;
 import ru.windcorp.progressia.client.world.entity.EntityRenderable;
 import ru.windcorp.progressia.client.world.tile.TileRender;
 import ru.windcorp.progressia.client.world.tile.TileRenderStack;
+import ru.windcorp.progressia.common.util.VectorUtil;
 import ru.windcorp.progressia.common.world.ChunkData;
 import ru.windcorp.progressia.common.world.ChunkDataListeners;
 import ru.windcorp.progressia.common.world.WorldData;
 import ru.windcorp.progressia.common.world.WorldDataListener;
 import ru.windcorp.progressia.common.world.entity.EntityData;
+import ru.windcorp.progressia.common.world.generic.ChunkSet;
+import ru.windcorp.progressia.common.world.generic.ChunkSets;
 import ru.windcorp.progressia.common.world.generic.GenericWorld;
 
 public class WorldRender
@@ -46,35 +51,52 @@ implements GenericWorld<
 	ChunkRender,
 	EntityRenderable
 > {
-	
+
 	private final WorldData data;
+	private final Client client;
 	
 	private final Map<ChunkData, ChunkRender> chunks =
 			Collections.synchronizedMap(new HashMap<>());
 	private final Map<EntityData, EntityRenderable> entityModels =
 			Collections.synchronizedMap(new WeakHashMap<>());
 	
-	public WorldRender(WorldData data) {
+	private final ChunkSet chunksToUpdate = ChunkSets.newSyncHashSet();
+	
+	public WorldRender(WorldData data, Client client) {
 		this.data = data;
+		this.client = client;
 		
 		data.addListener(ChunkDataListeners.createAdder(new ChunkUpdateListener(this)));
 		data.addListener(new WorldDataListener() {
 			@Override
 			public void onChunkLoaded(WorldData world, ChunkData chunk) {
-				chunks.put(chunk, new ChunkRender(WorldRender.this, chunk));
+				addChunk(chunk);
 			}
 			
 			@Override
 			public void beforeChunkUnloaded(WorldData world, ChunkData chunk) {
-				chunks.remove(chunk);
+				removeChunk(chunk);
 			}
 		});
 	}
+
+	protected void addChunk(ChunkData chunk) {
+		chunks.put(chunk, new ChunkRender(WorldRender.this, chunk));
+		markChunkForUpdate(chunk.getPosition());
+	}
 	
+	protected void removeChunk(ChunkData chunk) {
+		chunks.remove(chunk);
+	}
+
 	public WorldData getData() {
 		return data;
 	}
 	
+	public Client getClient() {
+		return client;
+	}
+	
 	public ChunkRender getChunk(ChunkData chunkData) {
 		return chunks.get(chunkData);
 	}
@@ -95,10 +117,67 @@ implements GenericWorld<
 	}
 	
 	public void render(ShapeRenderHelper renderer) {
+		updateChunks();
+		
 		getChunks().forEach(chunk -> chunk.render(renderer));
 		renderEntities(renderer);
 	}
 	
+	private void updateChunks() {
+		synchronized (chunksToUpdate) {
+			if (chunksToUpdate.isEmpty()) return;
+			
+			int updates = updateChunksNearLocalPlayer();
+			int maximumUpdates = getMaximumChunkUpdatesPerFrame();
+			
+			updateRandomChunks(maximumUpdates - updates);
+		}
+	}
+
+	private int updateChunksNearLocalPlayer() {
+		EntityData entity = getClient().getLocalPlayer().getEntity();
+		if (entity == null) return 0;
+		
+		int[] updates = new int[] { 0 };
+		
+		VectorUtil.iterateCuboidAround(entity.getChunkCoords(null), 3, chunkPos -> {
+			if (chunksToUpdate.contains(chunkPos)) {
+				getChunk(chunkPos).update();
+				chunksToUpdate.remove(chunkPos);
+				
+				updates[0]++;
+			}
+		});
+		
+		return updates[0];
+	}
+	
+	private void updateRandomChunks(int allowedUpdates) {
+		if (allowedUpdates <= 0) return;
+		
+		for (Iterator<Vec3i> it = chunksToUpdate.iterator(); it.hasNext();) {
+			Vec3i chunkPos = it.next();
+			ChunkRender chunk = getChunk(chunkPos);
+			
+			if (chunk != null) {
+				chunk.update();
+				allowedUpdates--;
+			}
+			
+			it.remove();
+			
+			if (allowedUpdates <= 0) return;
+		}
+	}
+
+	private int getMaximumChunkUpdatesPerFrame() {
+		return 1;
+	}
+	
+	public int getPendingChunkUpdates() {
+		return chunksToUpdate.size();
+	}
+
 	private void renderEntities(ShapeRenderHelper renderer) {
 		FaceCulling.push(false);
 		
@@ -122,5 +201,11 @@ implements GenericWorld<
 		return EntityRenderRegistry.getInstance().get(entity.getId())
 				.createRenderable(entity);
 	}
+	
+	public void markChunkForUpdate(Vec3i chunkPos) {
+		if (getData().getChunk(chunkPos) != null) {
+			chunksToUpdate.add(chunkPos);
+		}
+	}
 
 }
diff --git a/src/main/java/ru/windcorp/progressia/common/util/VectorUtil.java b/src/main/java/ru/windcorp/progressia/common/util/VectorUtil.java
index eaa02ed..4e7ac70 100644
--- a/src/main/java/ru/windcorp/progressia/common/util/VectorUtil.java
+++ b/src/main/java/ru/windcorp/progressia/common/util/VectorUtil.java
@@ -19,7 +19,7 @@ public class VectorUtil {
 		X, Y, Z, W;
 	}
 	
-	public static void forEachVectorInCuboid(
+	public static void iterateCuboid(
 			int x0, int y0, int z0,
 			int x1, int y1, int z1,
 			Consumer<? super Vec3i> action
@@ -38,6 +38,57 @@ public class VectorUtil {
 		Vectors.release(cursor);
 	}
 	
+	public static void iterateCuboid(
+			Vec3i vMin, Vec3i vMax,
+			Consumer<? super Vec3i> action
+	) {
+		iterateCuboid(vMin.x, vMin.y, vMin.z, vMax.x, vMax.y, vMax.z, action);
+	}
+	
+	public static void iterateCuboidAround(
+			int cx, int cy, int cz,
+			int dx, int dy, int dz,
+			Consumer<? super Vec3i> action
+	) {
+		if (dx < 0) throw new IllegalArgumentException("dx " + dx + " is negative");
+		if (dy < 0) throw new IllegalArgumentException("dy " + dx + " is negative");
+		if (dz < 0) throw new IllegalArgumentException("dz " + dx + " is negative");
+		
+		if (dx % 2 == 0) throw new IllegalArgumentException("dx " + dx + " is even, only odd accepted");
+		if (dy % 2 == 0) throw new IllegalArgumentException("dy " + dy + " is even, only odd accepted");
+		if (dz % 2 == 0) throw new IllegalArgumentException("dz " + dz + " is even, only odd accepted");
+		
+		dx /= 2;
+		dy /= 2;
+		dz /= 2;
+		
+		iterateCuboid(cx - dx, cy - dy, cz - dz, cx + dx + 1, cy + dy + 1, cz + dz + 1, action);
+	}
+	
+	public static void iterateCuboidAround(
+			Vec3i center,
+			Vec3i diameters,
+			Consumer<? super Vec3i> action
+	) {
+		iterateCuboidAround(center.x, center.y, center.z, diameters.x, diameters.y, diameters.z, action);
+	}
+	
+	public static void iterateCuboidAround(
+			int cx, int cy, int cz,
+			int diameter,
+			Consumer<? super Vec3i> action
+	) {
+		iterateCuboidAround(cx, cy, cz, diameter, diameter, diameter, action);
+	}
+	
+	public static void iterateCuboidAround(
+			Vec3i center,
+			int diameter,
+			Consumer<? super Vec3i> action
+	) {
+		iterateCuboidAround(center.x, center.y, center.z, diameter, action);
+	}
+	
 	public static void applyMat4(Vec3 in, Mat4 mat, Vec3 out) {
 		Vec4 vec4 = Vectors.grab4();
 		vec4.set(in, 1f);
diff --git a/src/main/java/ru/windcorp/progressia/common/world/ChunkData.java b/src/main/java/ru/windcorp/progressia/common/world/ChunkData.java
index ff9fc71..2e454e0 100644
--- a/src/main/java/ru/windcorp/progressia/common/world/ChunkData.java
+++ b/src/main/java/ru/windcorp/progressia/common/world/ChunkData.java
@@ -183,7 +183,7 @@ implements GenericChunk<
 	}
 	
 	public void forEachBlock(Consumer<Vec3i> action) {
-		VectorUtil.forEachVectorInCuboid(
+		VectorUtil.iterateCuboid(
 				0, 0, 0,
 				BLOCKS_PER_CHUNK, BLOCKS_PER_CHUNK, BLOCKS_PER_CHUNK,
 				action
diff --git a/src/main/java/ru/windcorp/progressia/common/world/generic/ChunkSets.java b/src/main/java/ru/windcorp/progressia/common/world/generic/ChunkSets.java
index a8b23d9..3e50dd3 100644
--- a/src/main/java/ru/windcorp/progressia/common/world/generic/ChunkSets.java
+++ b/src/main/java/ru/windcorp/progressia/common/world/generic/ChunkSets.java
@@ -2,9 +2,11 @@ package ru.windcorp.progressia.common.world.generic;
 
 import java.util.Iterator;
 import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
 
 import glm.vec._3.i.Vec3i;
-import gnu.trove.impl.sync.TSynchronizedLongSet;
 import gnu.trove.set.hash.TLongHashSet;
 
 public class ChunkSets {
@@ -14,13 +16,19 @@ public class ChunkSets {
 	}
 	
 	public static ChunkSet newSyncHashSet(Object mutex) {
-		return new LongBasedChunkSet(new TSynchronizedLongSet(new TLongHashSet(), mutex));
+		return new SynchronizedChunkSet(new LongBasedChunkSet(new TLongHashSet()), mutex);
 	}
 	
 	public static ChunkSet newSyncHashSet() {
-		return new LongBasedChunkSet(new TSynchronizedLongSet(new TLongHashSet()));
+		return newSyncHashSet(null);
 	}
 	
+	public static ChunkSet empty() {
+		return EMPTY_SET;
+	}
+	
+	private ChunkSets() {}
+	
 	private final static ChunkSet EMPTY_SET = new ChunkSet() {
 
 		@Override
@@ -89,10 +97,174 @@ public class ChunkSets {
 		
 	};
 	
-	public static ChunkSet empty() {
-		return EMPTY_SET;
+	private static class SynchronizedChunkSet implements ChunkSet {
+		
+		private final ChunkSet parent;
+		private final Object mutex;
+
+		public SynchronizedChunkSet(ChunkSet parent, Object mutex) {
+			Objects.requireNonNull(parent, "parent");
+			this.parent = parent;
+			
+			this.mutex = mutex == null ? this : mutex;
+		}
+
+		@Override
+		public Iterator<Vec3i> iterator() {
+			return parent.iterator(); // Must be synchronized manually by user!
+		}
+
+		@Override
+		public void forEach(Consumer<? super Vec3i> action) {
+			synchronized (mutex) { parent.forEach(action); }
+		}
+
+		@Override
+		public int size() {
+			synchronized (mutex) { return parent.size(); }
+		}
+
+		@Override
+		public boolean isEmpty() {
+			synchronized (mutex) { return parent.isEmpty(); }
+		}
+
+		@Override
+		public boolean contains(Vec3i pos) {
+			synchronized (mutex) { return parent.contains(pos); }
+		}
+
+		@Override
+		public boolean add(Vec3i pos) {
+			synchronized (mutex) { return parent.add(pos); }
+		}
+
+		@Override
+		public boolean remove(Vec3i pos) {
+			synchronized (mutex) { return parent.remove(pos); }
+		}
+
+		@Override
+		public boolean contains(int x, int y, int z) {
+			synchronized (mutex) { return parent.contains(x, y, z); }
+		}
+
+		@Override
+		public boolean add(int x, int y, int z) {
+			synchronized (mutex) { return parent.add(x, y, z); }
+		}
+
+		@Override
+		public boolean remove(int x, int y, int z) {
+			synchronized (mutex) { return parent.remove(x, y, z); }
+		}
+
+		@Override
+		public boolean contains(GenericChunk<?, ?, ?, ?> chunk) {
+			synchronized (mutex) { return parent.contains(chunk); }
+		}
+
+		@Override
+		public boolean add(GenericChunk<?, ?, ?, ?> chunk) {
+			synchronized (mutex) { return parent.add(chunk); }
+		}
+
+		@Override
+		public boolean remove(GenericChunk<?, ?, ?, ?> chunk) {
+			synchronized (mutex) { return parent.remove(chunk); }
+		}
+
+		@Override
+		public <C extends GenericChunk<C, ?, ?, ?>> void forEachIn(GenericWorld<?, ?, ?, C, ?> world,
+				Consumer<? super C> action) {
+			synchronized (mutex) { parent.forEachIn(world, action); }
+		}
+
+		@Override
+		public boolean containsAll(ChunkSet other) {
+			synchronized (mutex) { return parent.containsAll(other); }
+		}
+
+		@Override
+		public boolean containsAny(ChunkSet other) {
+			synchronized (mutex) { return parent.containsAny(other); }
+		}
+
+		@Override
+		public void addAll(ChunkSet other) {
+			synchronized (mutex) { parent.addAll(other); }
+		}
+
+		@Override
+		public void removeAll(ChunkSet other) {
+			synchronized (mutex) { parent.removeAll(other); }
+		}
+
+		@Override
+		public void retainAll(ChunkSet other) {
+			synchronized (mutex) { parent.retainAll(other); }
+		}
+
+		@Override
+		public void clear() {
+			synchronized (mutex) { parent.clear(); }
+		}
+
+		@Override
+		public boolean containsAll(Iterable<? extends Vec3i> other) {
+			synchronized (mutex) { return parent.containsAll(other); }
+		}
+
+		@Override
+		public boolean containsAny(Iterable<? extends Vec3i> other) {
+			synchronized (mutex) { return parent.containsAny(other); }
+		}
+
+		@Override
+		public void addAll(Iterable<? extends Vec3i> other) {
+			synchronized (mutex) { parent.addAll(other); }
+		}
+
+		@Override
+		public void removeAll(Iterable<? extends Vec3i> other) {
+			synchronized (mutex) { parent.removeAll(other); }
+		}
+
+		@Override
+		public void retainAll(Iterable<? extends Vec3i> other) {
+			synchronized (mutex) { parent.retainAll(other); }
+		}
+
+		@Override
+		public void removeIf(Predicate<? super Vec3i> condition) {
+			synchronized (mutex) { parent.removeIf(condition); }
+		}
+
+		@Override
+		public void retainIf(Predicate<? super Vec3i> condition) {
+			synchronized (mutex) { parent.retainIf(condition); }
+		}
+
+		@Override
+		public boolean containsAllChunks(Iterable<? extends GenericChunk<?, ?, ?, ?>> chunks) {
+			synchronized (mutex) { return parent.containsAllChunks(chunks); }
+		}
+
+		@Override
+		public boolean containsAnyChunks(Iterable<? extends GenericChunk<?, ?, ?, ?>> chunks) {
+			synchronized (mutex) { return parent.containsAnyChunks(chunks); }
+		}
+
+		@Override
+		public void addAllChunks(Iterable<? extends GenericChunk<?, ?, ?, ?>> chunks) {
+			synchronized (mutex) { parent.addAllChunks(chunks); }
+		}
+
+		@Override
+		public void removeAllChunks(Iterable<? extends GenericChunk<?, ?, ?, ?>> chunks) {
+			synchronized (mutex) { parent.removeAllChunks(chunks); }
+		}
+		
 	}
-	
-	private ChunkSets() {}
 
 }
diff --git a/src/main/java/ru/windcorp/progressia/common/world/generic/GenericChunk.java b/src/main/java/ru/windcorp/progressia/common/world/generic/GenericChunk.java
index 8dc3cf8..45a6ad0 100644
--- a/src/main/java/ru/windcorp/progressia/common/world/generic/GenericChunk.java
+++ b/src/main/java/ru/windcorp/progressia/common/world/generic/GenericChunk.java
@@ -55,7 +55,7 @@ public interface GenericChunk<
 	}
 	
 	default void forEachBiC(Consumer<? super Vec3i> action) {
-		VectorUtil.forEachVectorInCuboid(
+		VectorUtil.iterateCuboid(
 				0,                0,                0,
 				BLOCKS_PER_CHUNK, BLOCKS_PER_CHUNK, BLOCKS_PER_CHUNK,
 				action
@@ -63,7 +63,7 @@ public interface GenericChunk<
 	}
 	
 	default void forEachBiW(Consumer<? super Vec3i> action) {
-		VectorUtil.forEachVectorInCuboid(
+		VectorUtil.iterateCuboid(
 				Coordinates.getInWorld(getX(), 0),
 				Coordinates.getInWorld(getY(), 0),
 				Coordinates.getInWorld(getZ(), 0),
diff --git a/src/main/java/ru/windcorp/progressia/server/world/TickAndUpdateUtil.java b/src/main/java/ru/windcorp/progressia/server/world/TickAndUpdateUtil.java
index f260675..a38ccd7 100644
--- a/src/main/java/ru/windcorp/progressia/server/world/TickAndUpdateUtil.java
+++ b/src/main/java/ru/windcorp/progressia/server/world/TickAndUpdateUtil.java
@@ -112,49 +112,6 @@ public class TickAndUpdateUtil {
 		tickEntity(EntityLogicRegistry.getInstance().get(data.getId()), data, TickContextMutable.start().withServer(server).build());
 	}
 	
-//	public static BlockTickContext getBlockTickContext(
-//			Server server,
-//			Vec3i blockInWorld
-//	) {
-//		MutableBlockTickContext result = new MutableBlockTickContext();
-//		result.init(server, blockInWorld);
-//		return result;
-//	}
-//	
-//	public static TileTickContext getTileTickContext(
-//			Server server,
-//			Vec3i blockInWorld,
-//			BlockFace face,
-//			int layer
-//	) {
-//		MutableTileTickContext result = new MutableTileTickContext();
-//		result.init(server, blockInWorld, face, layer);
-//		return result;
-//	}
-//	
-//	public static TileTickContext getTileTickContext(
-//			Server server,
-//			TileDataStack stack,
-//			int index
-//	) {
-//		MutableTileTickContext result = new MutableTileTickContext();
-//		result.init(server, stack, index);
-//		return result;
-//	}
-//	
-//	public static TileTickContext getTileTickContext(
-//			Server server,
-//			TileReference ref
-//	) {
-//		MutableTileTickContext result = new MutableTileTickContext();
-//		result.init(server, ref);
-//		return result;
-//	}
-//	
-//	public static TickContext getTickContext(Server server) {
-//		return getBlockTickContext(server, null);
-//	}
-	
 	private TickAndUpdateUtil() {}
 
 }
diff --git a/src/main/java/ru/windcorp/progressia/test/LayerTestGUI.java b/src/main/java/ru/windcorp/progressia/test/LayerTestGUI.java
index 94d80a1..0395f35 100755
--- a/src/main/java/ru/windcorp/progressia/test/LayerTestGUI.java
+++ b/src/main/java/ru/windcorp/progressia/test/LayerTestGUI.java
@@ -73,6 +73,12 @@ public class LayerTestGUI extends GUILayer {
 				128
 		));
 		
+		panel.addChild(new DynamicLabel(
+				"ChunkUpdatesDisplay", new Font().withColor(0x37A3E6).deriveShadow(),
+				() -> "Pending updates: " + Integer.toString(ClientState.getInstance().getWorld().getPendingChunkUpdates()),
+				128
+		));
+		
 		panel.getChildren().forEach(c -> {
 			if (c instanceof Label) {
 				labels.add((Label) c);
diff --git a/src/main/java/ru/windcorp/progressia/test/TestPlayerControls.java b/src/main/java/ru/windcorp/progressia/test/TestPlayerControls.java
index d00ca09..8aea90f 100644
--- a/src/main/java/ru/windcorp/progressia/test/TestPlayerControls.java
+++ b/src/main/java/ru/windcorp/progressia/test/TestPlayerControls.java
@@ -29,8 +29,8 @@ public class TestPlayerControls {
 	
 	private TestPlayerControls() {}
 	
-	private static final double MODE_SWITCH_MAX_DELAY = 100 * Units.MILLISECONDS;
-	private static final double MIN_JUMP_DELAY = 200 * Units.MILLISECONDS;
+	private static final double MODE_SWITCH_MAX_DELAY = 300 * Units.MILLISECONDS;
+	private static final double MIN_JUMP_DELAY = 400 * Units.MILLISECONDS;
 
 	// Horizontal and vertical max control speed when flying
 	private static final float FLYING_SPEED = 6.0f * Units.METERS_PER_SECOND;