diff --git a/source/client/StarClientApplication.cpp b/source/client/StarClientApplication.cpp
index 19ea9e0..6c891c2 100644
--- a/source/client/StarClientApplication.cpp
+++ b/source/client/StarClientApplication.cpp
@@ -418,7 +418,7 @@ void ClientApplication::render() {
       LogMap::set("client_render_world_client", strf(u8"{:05d}\u00b5s", Time::monotonicMicroseconds() - clientStart));
 
       auto paintStart = Time::monotonicMicroseconds();
-      m_worldPainter->render(m_renderData, [&]() { worldClient->waitForLighting(); });
+      m_worldPainter->render(m_renderData, [&]() { worldClient->waitForLighting(&m_renderData.lightMap); });
       LogMap::set("client_render_world_painter", strf(u8"{:05d}\u00b5s", Time::monotonicMicroseconds() - paintStart));
       LogMap::set("client_render_world_total", strf(u8"{:05d}\u00b5s", Time::monotonicMicroseconds() - totalStart));
     }
diff --git a/source/frontend/StarClientCommandProcessor.cpp b/source/frontend/StarClientCommandProcessor.cpp
index 00ec2e5..933d87b 100644
--- a/source/frontend/StarClientCommandProcessor.cpp
+++ b/source/frontend/StarClientCommandProcessor.cpp
@@ -155,24 +155,27 @@ String ClientCommandProcessor::boxes() {
   if (!adminCommandAllowed())
     return "You must be an admin to use this command.";
 
-  return strf("Geometry debug display {}",
-      m_universeClient->worldClient()->toggleCollisionDebug()
-      ? "enabled" : "disabled");
+  auto worldClient = m_universeClient->worldClient();
+  bool state = !worldClient->collisionDebug();
+  worldClient->setCollisionDebug(state);
+  return strf("Geometry debug display {}", state ? "enabled" : "disabled");
 }
 
 String ClientCommandProcessor::fullbright() {
   if (!adminCommandAllowed())
     return "You must be an admin to use this command.";
 
-  return strf("Fullbright render lighting {}",
-      m_universeClient->worldClient()->toggleFullbright()
-      ? "enabled" : "disabled");
+  auto worldClient = m_universeClient->worldClient();
+  bool state = !worldClient->fullBright();
+  worldClient->setFullBright(state);
+  return strf("Fullbright render lighting {}", state ? "enabled" : "disabled");
 }
 
 String ClientCommandProcessor::asyncLighting() {
-  return strf("Asynchronous render lighting {}",
-    m_universeClient->worldClient()->toggleAsyncLighting()
-    ? "enabled" : "disabled");
+  auto worldClient = m_universeClient->worldClient();
+  bool state = !worldClient->asyncLighting();
+  worldClient->setAsyncLighting(state);
+  return strf("Asynchronous render lighting {}", state ? "enabled" : "disabled");
 }
 
 String ClientCommandProcessor::setGravity(String const& argumentsString) {
diff --git a/source/game/StarUniverseClient.cpp b/source/game/StarUniverseClient.cpp
index c492d89..f355965 100644
--- a/source/game/StarUniverseClient.cpp
+++ b/source/game/StarUniverseClient.cpp
@@ -123,6 +123,7 @@ Maybe<String> UniverseClient::connect(UniverseConnection connection, bool allowA
     m_mainPlayer->setClientContext(m_clientContext);
     m_mainPlayer->setStatistics(m_statistics);
     m_worldClient = make_shared<WorldClient>(m_mainPlayer);
+    m_worldClient->setAsyncLighting(true);
     for (auto& pair : m_luaCallbacks)
       m_worldClient->setLuaCallbacks(pair.first, pair.second);
 
diff --git a/source/game/StarWorldClient.cpp b/source/game/StarWorldClient.cpp
index d510920..470ff42 100644
--- a/source/game/StarWorldClient.cpp
+++ b/source/game/StarWorldClient.cpp
@@ -37,7 +37,7 @@ WorldClient::WorldClient(PlayerPtr mainPlayer) {
   m_currentStep = 0;
   m_currentServerStep = 0.0;
   m_fullBright = false;
-  m_asyncLighting = true;
+  m_asyncLighting = false;
   m_worldDimTimer = GameTimer(m_clientConfig.getFloat("worldDimTime"));
   m_worldDimTimer.setDone();
   m_worldDimLevel = 0.0f;
@@ -90,20 +90,20 @@ WorldClient::WorldClient(PlayerPtr mainPlayer) {
   m_altMusicActive = false;
 
   m_stopLightingThread = false;
-  m_lightingThread = Thread::invoke("WorldClient::lightingMain", mem_fn(&WorldClient::lightingMain), this);
-  m_renderData = nullptr;
 
   clearWorld();
 }
 
 WorldClient::~WorldClient() {
-  m_stopLightingThread = true;
-  {
-    MutexLocker locker(m_lightingMutex);
-    m_lightingCond.broadcast();
-  }
+  if (m_lightingThread) {
+    m_stopLightingThread = true;
+    {
+      MutexLocker locker(m_lightingMutex);
+      m_lightingCond.broadcast();
+    }
 
-  m_lightingThread.finish();
+    m_lightingThread.finish();
+  }
   clearWorld();
 }
 
@@ -404,6 +404,9 @@ RectI WorldClient::clientWindow() const {
 }
 
 void WorldClient::render(WorldRenderData& renderData, unsigned bufferTiles) {
+  if (!m_lightingThread && m_asyncLighting)
+    m_lightingThread = Thread::invoke("WorldClient::lightingMain", mem_fn(&WorldClient::lightingMain), this);
+
   renderData.clear();
   if (!inWorld())
     return;
@@ -474,13 +477,10 @@ void WorldClient::render(WorldRenderData& renderData, unsigned bufferTiles) {
       m_lightingCalculator.addSpreadLight(position, Color::v3bToFloat(lightPair.second));
     }
 
-    if (m_asyncLighting) {
-      m_renderData = &renderData;
+    if (m_asyncLighting)
       m_lightingCond.signal();
-    }
-    else {
-      m_lightingCalculator.calculate(renderData.lightMap);
-    }
+    else
+      m_lightingCalculator.calculate(m_lightMap);
   }
 
   float pulseAmount = Root::singleton().assets()->json("/highlights.config:interactivePulseAmount").toFloat();
@@ -725,21 +725,30 @@ void WorldClient::resetGravity() {
   m_overrideGravity = {};
 }
 
-bool WorldClient::toggleFullbright() {
-  m_fullBright = !m_fullBright;
+bool WorldClient::fullBright() const {
   return m_fullBright;
 }
 
-bool WorldClient::toggleAsyncLighting() {
-  m_asyncLighting = !m_asyncLighting;
+void WorldClient::setFullBright(bool fullBright) {
+  m_fullBright = fullBright;
+}
+
+bool WorldClient::asyncLighting() const {
   return m_asyncLighting;
 }
 
-bool WorldClient::toggleCollisionDebug() {
-  m_collisionDebug = !m_collisionDebug;
+void WorldClient::setAsyncLighting(bool asyncLighting) {
+  m_asyncLighting = asyncLighting;
+}
+
+bool WorldClient::collisionDebug() const {
   return m_collisionDebug;
 }
 
+void WorldClient::setCollisionDebug(bool collisionDebug) {
+  m_collisionDebug = collisionDebug;
+}
+
 void WorldClient::handleIncomingPackets(List<PacketPtr> const& packets) {
   auto& root = Root::singleton();
   auto materialDatabase = root.materialDatabase();
@@ -1393,8 +1402,10 @@ void WorldClient::collectLiquid(List<Vec2I> const& tilePositions, LiquidId liqui
   m_outgoingPackets.append(make_shared<CollectLiquidPacket>(tilePositions, liquidId));
 }
 
-void WorldClient::waitForLighting() {
+void WorldClient::waitForLighting(Image* out) {
   MutexLocker lock(m_lightingMutex);
+  if (out)
+    *out = move(m_lightMap);
 }
 
 WorldClient::BroadcastCallback& WorldClient::broadcastCallback() {
@@ -1644,15 +1655,10 @@ void WorldClient::lightingMain() {
     if (m_stopLightingThread)
       return;
 
-    if (WorldRenderData* renderData = m_renderData) {
-      int64_t start = Time::monotonicMicroseconds();
-
-      lightingTileGather();
-
-      m_lightingCalculator.calculate(renderData->lightMap);
-      m_renderData = nullptr;
-      LogMap::set("client_render_world_async_light_calc", strf(u8"{:05d}\u00b5s", Time::monotonicMicroseconds() - start));
-    }
+    int64_t start = Time::monotonicMicroseconds();
+    lightingTileGather();
+    m_lightingCalculator.calculate(m_lightMap);
+    LogMap::set("client_render_world_async_light_calc", strf(u8"{:05d}\u00b5s", Time::monotonicMicroseconds() - start));
 
     continue;
 
diff --git a/source/game/StarWorldClient.hpp b/source/game/StarWorldClient.hpp
index 7298863..a8080f1 100644
--- a/source/game/StarWorldClient.hpp
+++ b/source/game/StarWorldClient.hpp
@@ -122,11 +122,14 @@ public:
   void resetGravity();
 
   // Disable normal client-side lighting algorithm, everything full brightness.
-  bool toggleFullbright();
+  bool fullBright() const;
+  void setFullBright(bool fullBright);
   // Disable asynchronous client-side lighting algorithm, run on main thread.
-  bool toggleAsyncLighting();
+  bool asyncLighting() const;
+  void setAsyncLighting(bool asyncLighting);
   // Spatial log generated collision geometry.
-  bool toggleCollisionDebug();
+  bool collisionDebug() const;
+  void setCollisionDebug(bool collisionDebug);
 
   void handleIncomingPackets(List<PacketPtr> const& packets);
   List<PacketPtr> getOutgoingPackets();
@@ -167,7 +170,7 @@ public:
 
   void collectLiquid(List<Vec2I> const& tilePositions, LiquidId liquidId);
 
-  void waitForLighting();
+  void waitForLighting(Image* out = nullptr);
 
   typedef std::function<bool(PlayerPtr, StringView)> BroadcastCallback;
   BroadcastCallback& broadcastCallback();
@@ -269,7 +272,7 @@ private:
 
   Mutex m_lightingMutex;
   ConditionVariable m_lightingCond;
-  atomic<WorldRenderData*> m_renderData;
+  Image m_lightMap;
   atomic<bool> m_stopLightingThread;
 
   SkyPtr m_sky;
diff --git a/source/game/StarWorldServerThread.cpp b/source/game/StarWorldServerThread.cpp
index 1b7d23a..35d6225 100644
--- a/source/game/StarWorldServerThread.cpp
+++ b/source/game/StarWorldServerThread.cpp
@@ -269,7 +269,7 @@ void WorldServerThread::update(WorldServerFidelity fidelity) {
 
   float dt = ServerGlobalTimestep * GlobalTimescale;
   m_worldServer->setFidelity(fidelity);
-  if (!m_pause || *m_pause == false)
+  if (dt > 0.0f && (!m_pause || *m_pause == false))
     m_worldServer->update(dt);
 
   List<Message> messages;
diff --git a/source/test/StarTestUniverse.cpp b/source/test/StarTestUniverse.cpp
index 4602f34..a7b9dd2 100644
--- a/source/test/StarTestUniverse.cpp
+++ b/source/test/StarTestUniverse.cpp
@@ -42,7 +42,7 @@ TestUniverse::~TestUniverse() {
 void TestUniverse::warpPlayer(WorldId worldId) {
   m_client->warpPlayer(WarpToWorld(worldId), true);
   while (m_mainPlayer->isTeleporting() || m_client->playerWorld().empty()) {
-    m_client->update();
+    m_client->update(0.016f);
     Thread::sleep(16);
   }
 }
@@ -53,7 +53,7 @@ WorldId TestUniverse::currentPlayerWorld() const {
 
 void TestUniverse::update(unsigned times) {
   for (unsigned i = 0; i < times; ++i) {
-    m_client->update();
+    m_client->update(0.016f);
     Thread::sleep(16);
   }
 }