diff --git a/doomsday/apps/client/include/client/clientsubsector.h b/doomsday/apps/client/include/client/clientsubsector.h
index 7648601583..a2717a7104 100644
--- a/doomsday/apps/client/include/client/clientsubsector.h
+++ b/doomsday/apps/client/include/client/clientsubsector.h
@@ -92,8 +92,8 @@ class ClientSubsector : public Subsector, public ILightSource
      *
      * @param callback  Function to call for each edge loop.
      */
-    de::LoopResult forAllEdgeLoops(std::function<de::LoopResult (ClEdgeLoop       &)> func);
-    de::LoopResult forAllEdgeLoops(std::function<de::LoopResult (ClEdgeLoop const &)> func) const;
+    de::LoopResult forAllEdgeLoops(const std::function<de::LoopResult (ClEdgeLoop       &)> &func);
+    de::LoopResult forAllEdgeLoops(const std::function<de::LoopResult (ClEdgeLoop const &)> &func) const;
 
 //- Audio environment -------------------------------------------------------------------
 
diff --git a/doomsday/apps/client/include/clientapp.h b/doomsday/apps/client/include/clientapp.h
index 2aac04ea38..9bb8fb781e 100644
--- a/doomsday/apps/client/include/clientapp.h
+++ b/doomsday/apps/client/include/clientapp.h
@@ -79,7 +79,7 @@ class ClientApp : public de::BaseGuiApp, public DoomsdayApp
     static void alert(de::String const &msg, de::LogEntry::Level level = de::LogEntry::Message);
 
     static ClientPlayer &player(int console);
-    static de::LoopResult forLocalPlayers(std::function<de::LoopResult (ClientPlayer &)> func);
+    static de::LoopResult forLocalPlayers(const std::function<de::LoopResult (ClientPlayer &)> &func);
 
     static ClientApp &          app();
     static ConfigProfiles &     logSettings();
diff --git a/doomsday/apps/client/include/resource/clientmaterial.h b/doomsday/apps/client/include/resource/clientmaterial.h
index 788c7d2426..1b82208c2f 100644
--- a/doomsday/apps/client/include/resource/clientmaterial.h
+++ b/doomsday/apps/client/include/resource/clientmaterial.h
@@ -45,7 +45,9 @@ class ClientMaterial : public world::Material
      */
     ClientMaterial(world::MaterialManifest &manifest);
 
-    ~ClientMaterial();
+    ~ClientMaterial() override;
+
+    bool isAnimated() const override;
 
     /**
      * Returns a human-friendly, textual description of the full material configuration.
@@ -200,7 +202,7 @@ class ClientMaterial : public world::Material
      *
      * @param func  Callback to make for each Decoration.
      */
-    de::LoopResult forAllDecorations(std::function<de::LoopResult (Decoration &)> func) const;
+    de::LoopResult forAllDecorations(const std::function<de::LoopResult (Decoration &)> &func) const;
 
     /**
      * Add a new (light) decoration to the material.
@@ -242,7 +244,7 @@ class ClientMaterial : public world::Material
      *
      * @param func  Callback to make for each Animator.
      */
-    de::LoopResult forAllAnimators(std::function<de::LoopResult (MaterialAnimator &)> func) const;
+    de::LoopResult forAllAnimators(const std::function<de::LoopResult (MaterialAnimator &)> &func) const;
 
     /**
      * Destroy all the MaterialAnimators for the material.
diff --git a/doomsday/apps/client/include/world/sector.h b/doomsday/apps/client/include/world/sector.h
index 367487fa29..af56d6a48e 100644
--- a/doomsday/apps/client/include/world/sector.h
+++ b/doomsday/apps/client/include/world/sector.h
@@ -238,7 +238,7 @@ class Sector : public world::MapElement
      *
      * @param callback  Function to call for each Subsector.
      */
-    de::LoopResult forAllSubsectors(std::function<de::LoopResult (world::Subsector &)> callback) const;
+    de::LoopResult forAllSubsectors(const std::function<de::LoopResult (world::Subsector &)> &callback) const;
 
     /**
      * Generate a new Subsector from the given set of map @a subspaces.
diff --git a/doomsday/apps/client/src/client/clientsubsector.cpp b/doomsday/apps/client/src/client/clientsubsector.cpp
index 0a5beaf3c1..0c829d31f9 100644
--- a/doomsday/apps/client/src/client/clientsubsector.cpp
+++ b/doomsday/apps/client/src/client/clientsubsector.cpp
@@ -1027,10 +1027,10 @@ DENG2_PIMPL(ClientSubsector)
 
         ds.markForUpdate(false);
 
-        // Clear any existing decorations.
         qDeleteAll(ds.decorations);
         ds.decorations.clear();
 
+        // Clear any existing decorations.
         if (surface.hasMaterial())
         {
             Vector2f materialOrigin;
@@ -1471,7 +1471,7 @@ dint ClientSubsector::edgeLoopCount() const
     return (bool(d->boundaryData->outerLoop) ? 1 : 0) + d->boundaryData->innerLoops.count();
 }
 
-LoopResult ClientSubsector::forAllEdgeLoops(std::function<LoopResult (ClEdgeLoop &)> func)
+LoopResult ClientSubsector::forAllEdgeLoops(const std::function<LoopResult (ClEdgeLoop &)> &func)
 {
     d->initBoundaryDataIfNeeded();
     DENG2_ASSERT(bool(d->boundaryData->outerLoop));
@@ -1487,7 +1487,7 @@ LoopResult ClientSubsector::forAllEdgeLoops(std::function<LoopResult (ClEdgeLoop
     return LoopContinue;
 }
 
-LoopResult ClientSubsector::forAllEdgeLoops(std::function<LoopResult (ClEdgeLoop const &)> func) const
+LoopResult ClientSubsector::forAllEdgeLoops(const std::function<LoopResult (ClEdgeLoop const &)> &func) const
 {
     d->initBoundaryDataIfNeeded();
     DENG2_ASSERT(bool(d->boundaryData->outerLoop));
@@ -1848,14 +1848,16 @@ void ClientSubsector::decorate()
 {
     LOG_AS("ClientSubsector::decorate");
 
-    auto decorateFunc = [this] (Surface &surface)
-    {
-        d->decorate(surface);
-        return LoopContinue;
-    };
+    if (!hasDecorations()) return;
+
+//    auto decorateFunc = [this] (Surface &surface)
+//    {
+//        d->decorate(surface);
+//        return LoopContinue;
+//    };
 
     // Surfaces of the edge loops.
-    forAllEdgeLoops([this, &decorateFunc] (ClEdgeLoop const &loop)
+    forAllEdgeLoops([this/*, &decorateFunc*/] (ClEdgeLoop const &loop)
     {
         SubsectorCirculator it(&loop.first());
         do
diff --git a/doomsday/apps/client/src/clientapp.cpp b/doomsday/apps/client/src/clientapp.cpp
index 269223d173..bde4c86902 100644
--- a/doomsday/apps/client/src/clientapp.cpp
+++ b/doomsday/apps/client/src/clientapp.cpp
@@ -817,7 +817,7 @@ ClientPlayer &ClientApp::player(int console) // static
     return DoomsdayApp::players().at(console).as<ClientPlayer>();
 }
 
-LoopResult ClientApp::forLocalPlayers(std::function<LoopResult (ClientPlayer &)> func) // static
+LoopResult ClientApp::forLocalPlayers(const std::function<LoopResult (ClientPlayer &)> &func) // static
 {
     auto const &players = DoomsdayApp::players();
     for (int i = 0; i < players.count(); ++i)
diff --git a/doomsday/apps/client/src/gl/dgl_draw.cpp b/doomsday/apps/client/src/gl/dgl_draw.cpp
index 7c582b25a0..2d1ecb9e2a 100644
--- a/doomsday/apps/client/src/gl/dgl_draw.cpp
+++ b/doomsday/apps/client/src/gl/dgl_draw.cpp
@@ -39,6 +39,8 @@ using namespace de;
 
 uint constexpr MAX_TEX_COORDS = 2;
 
+static unsigned s_drawCallCount = 0;
+
 struct DGLDrawState
 {
     struct Vertex
@@ -335,7 +337,7 @@ struct DGLDrawState
 
         // Upload the vertex data.
         GLData::DrawBuffer &buf = nextBuffer();
-        buf.arrayData.setData(&vertices[0], sizeof(Vertex) * vertices.size(), gl::Stream);
+        buf.arrayData.setData(&vertices[0], sizeof(Vertex) * vertices.size(), gl::Dynamic);
 
 #if defined (DENG_HAVE_VAOS)
         GL.glBindVertexArray(buf.vertexArray);
@@ -428,7 +430,7 @@ struct DGLDrawState
         gl->shader.beginUse();
         {
             glBindArrays();
-            LIBGUI_GL.glDrawArrays(glPrimitive(), 0, numVertices());
+            LIBGUI_GL.glDrawArrays(glPrimitive(), 0, numVertices()); ++s_drawCallCount;
             LIBGUI_ASSERT_GL_OK();
             glUnbindArrays();
         }
@@ -445,6 +447,9 @@ void DGL_Shutdown()
 
 void DGL_BeginFrame()
 {
+    qDebug() << "draw calls:" << s_drawCallCount;
+    s_drawCallCount = 0;
+
     if (dglDraw.gl)
     {
         // Reuse buffers every frame.
diff --git a/doomsday/apps/client/src/resource/clientmaterial.cpp b/doomsday/apps/client/src/resource/clientmaterial.cpp
index 72d897d51b..127fd644ac 100644
--- a/doomsday/apps/client/src/resource/clientmaterial.cpp
+++ b/doomsday/apps/client/src/resource/clientmaterial.cpp
@@ -153,6 +153,22 @@ ClientMaterial::ClientMaterial(world::MaterialManifest &manifest)
 ClientMaterial::~ClientMaterial()
 {}
 
+bool ClientMaterial::isAnimated() const
+{
+    if (Material::isAnimated())
+    {
+        return true;
+    }
+    for (const auto &decor : d->decorations)
+    {
+        if (decor->isAnimated())
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
 AudioEnvironmentId ClientMaterial::audioEnvironment() const
 {
     return (isDrawable()? d->audioEnvironment : AE_NONE);
@@ -168,7 +184,7 @@ int ClientMaterial::decorationCount() const
     return d->decorations.count();
 }
 
-LoopResult ClientMaterial::forAllDecorations(std::function<LoopResult (Decoration &)> func) const
+LoopResult ClientMaterial::forAllDecorations(const std::function<LoopResult (Decoration &)> &func) const
 {
     for (Decoration *decor : d.getConst()->decorations)
     {
@@ -214,7 +230,7 @@ MaterialAnimator &ClientMaterial::getAnimator(MaterialVariantSpec const &spec)
     return *d->findAnimator(spec, true/*create*/);
 }
 
-LoopResult ClientMaterial::forAllAnimators(std::function<LoopResult (MaterialAnimator &)> func) const
+LoopResult ClientMaterial::forAllAnimators(const std::function<LoopResult (MaterialAnimator &)> &func) const
 {
     for (MaterialAnimator *animator : d.getConst()->animators)
     {
diff --git a/doomsday/apps/client/src/world/base/clientserverworld.cpp b/doomsday/apps/client/src/world/base/clientserverworld.cpp
index a179e31e46..3b2935f425 100644
--- a/doomsday/apps/client/src/world/base/clientserverworld.cpp
+++ b/doomsday/apps/client/src/world/base/clientserverworld.cpp
@@ -644,7 +644,8 @@ DENG2_PIMPL(ClientServerWorld)
 
         // Rewind/restart material animators.
         /// @todo Only rewind animators responsible for map-surface contexts.
-        world::Materials::get().forAllMaterials([] (world::Material &material)
+        world::Materials::get().updateLookup();
+        world::Materials::get().forAnimatedMaterials([] (world::Material &material)
         {
             return material.as<ClientMaterial>().forAllAnimators([] (MaterialAnimator &animator)
             {
diff --git a/doomsday/apps/client/src/world/base/p_ticker.cpp b/doomsday/apps/client/src/world/base/p_ticker.cpp
index fba5f58685..fff29a1c11 100644
--- a/doomsday/apps/client/src/world/base/p_ticker.cpp
+++ b/doomsday/apps/client/src/world/base/p_ticker.cpp
@@ -34,7 +34,7 @@ void P_Ticker(timespan_t elapsed)
     /// @todo Each context animator should be driven by a more relevant ticker, rather
     /// than using the playsim's ticker for all contexts. (e.g., animators for the UI
     /// context should be driven separately).
-    world::Materials::get().forAllMaterials([&elapsed] (world::Material &material)
+    world::Materials::get().forAnimatedMaterials([&elapsed] (world::Material &material)
     {
         auto &mat = material.as<ClientMaterial>();
         for (int i = mat.animatorCount() - 1; i >= 0; --i)
diff --git a/doomsday/apps/client/src/world/base/sector.cpp b/doomsday/apps/client/src/world/base/sector.cpp
index 8564e33fb7..85369d2673 100644
--- a/doomsday/apps/client/src/world/base/sector.cpp
+++ b/doomsday/apps/client/src/world/base/sector.cpp
@@ -349,7 +349,7 @@ dint Sector::subsectorCount() const
     return d->subsectors.count();
 }
 
-LoopResult Sector::forAllSubsectors(std::function<LoopResult(Subsector &)> callback) const
+LoopResult Sector::forAllSubsectors(const std::function<LoopResult(Subsector &)> &callback) const
 {
     for (Subsector *subsec : d->subsectors)
     {
diff --git a/doomsday/apps/libdoomsday/include/doomsday/world/material.h b/doomsday/apps/libdoomsday/include/doomsday/world/material.h
index efcd67325e..07e08d7f49 100644
--- a/doomsday/apps/libdoomsday/include/doomsday/world/material.h
+++ b/doomsday/apps/libdoomsday/include/doomsday/world/material.h
@@ -111,6 +111,8 @@ class LIBDOOMSDAY_PUBLIC Material : public MapElement
         return (_flags & Valid) != 0;
     }
 
+    virtual bool isAnimated() const;
+
     /**
      * Change the do-not-draw property of the material according to @a yes.
      */
diff --git a/doomsday/apps/libdoomsday/include/doomsday/world/materials.h b/doomsday/apps/libdoomsday/include/doomsday/world/materials.h
index 0f9d124fdb..329d2d232c 100644
--- a/doomsday/apps/libdoomsday/include/doomsday/world/materials.h
+++ b/doomsday/apps/libdoomsday/include/doomsday/world/materials.h
@@ -193,7 +193,11 @@ class LIBDOOMSDAY_PUBLIC Materials
      *
      * @param func  Callback to make for each Material.
      */
-    de::LoopResult forAllMaterials(std::function<de::LoopResult (Material &)> func) const;
+    de::LoopResult forAllMaterials(const std::function<de::LoopResult (Material &)> &func) const;
+
+    de::LoopResult forAnimatedMaterials(const std::function<de::LoopResult (Material &)> &func) const;
+
+    void updateLookup();
 
 private:
     DENG2_PRIVATE(d)
diff --git a/doomsday/apps/libdoomsday/src/world/material.cpp b/doomsday/apps/libdoomsday/src/world/material.cpp
index bd8f8f07b9..948addbf3d 100644
--- a/doomsday/apps/libdoomsday/src/world/material.cpp
+++ b/doomsday/apps/libdoomsday/src/world/material.cpp
@@ -222,6 +222,11 @@ void Material::setHeight(int newHeight)
     setDimensions(Vector2ui(width(), newHeight));
 }
 
+bool Material::isAnimated() const
+{
+    return hasAnimatedTextureLayers();
+}
+
 void Material::setWidth(int newWidth)
 {
     setDimensions(Vector2ui(newWidth, height()));
diff --git a/doomsday/apps/libdoomsday/src/world/materials.cpp b/doomsday/apps/libdoomsday/src/world/materials.cpp
index 2fa2dd3b8c..d620cd3d99 100644
--- a/doomsday/apps/libdoomsday/src/world/materials.cpp
+++ b/doomsday/apps/libdoomsday/src/world/materials.cpp
@@ -23,6 +23,7 @@
 #include "doomsday/resource/resources.h"
 
 #include <de/memory.h>
+#include <unordered_set>
 
 using namespace de;
 
@@ -56,6 +57,8 @@ DENG2_PIMPL(Materials)
     QList<Material *> materials;       ///< From all schemes.
     int materialManifestCount = 0;     ///< Total number of material manifests (in all schemes).
 
+    std::unordered_set<Material *> animatedMaterialsSubset; ///< Subset of materials (not owned) that need to animate.
+
     MaterialManifestGroups materialGroups;
 
     uint materialManifestIdMapSize = 0;
@@ -158,7 +161,9 @@ DENG2_PIMPL(Materials)
     /// Observes Material Deletion.
     void materialBeingDeleted(Material const &material)
     {
-        materials.removeOne(const_cast<Material *>(&material));
+        Material *pMat = const_cast<Material *>(&material);
+        materials.removeOne(pMat);
+        animatedMaterialsSubset.erase(pMat);
     }
 };
 
@@ -269,7 +274,7 @@ dint Materials::materialCount() const
     return d->materials.count();
 }
 
-LoopResult Materials::forAllMaterials(std::function<LoopResult (Material &)> func) const
+LoopResult Materials::forAllMaterials(const std::function<LoopResult (Material &)> &func) const
 {
     for (Material *mat : d.getConst()->materials)
     {
@@ -281,6 +286,30 @@ LoopResult Materials::forAllMaterials(std::function<LoopResult (Material &)> fun
     return LoopContinue;
 }
 
+LoopResult Materials::forAnimatedMaterials(const std::function<LoopResult (Material &)> &func) const
+{
+    for (Material *mat : d.getConst()->animatedMaterialsSubset)
+    {
+        if (auto result = func(*mat))
+        {
+            return result;
+        }
+    }
+    return LoopContinue;
+}
+
+void Materials::updateLookup()
+{
+    d->animatedMaterialsSubset.clear();
+    for (auto *mat : d->materials)
+    {
+        if (mat->isAnimated())
+        {
+            d->animatedMaterialsSubset.insert(mat);
+        }
+    }
+}
+
 Materials::MaterialManifestGroup &Materials::newMaterialGroup()
 {
     // Allocating one by one is inefficient, but it doesn't really matter.