diff --git a/TODO b/TODO
index 9e9fce7..aa22dac 100644
--- a/TODO
+++ b/TODO
@@ -22,6 +22,7 @@ Technology Preview 2 :
    => Don't display the water if it's below all ground
    => Add the sun position
    => Try to overcome the near frustum cutting
+   => Disable texture reflection of light (dependant on camera location)
 - Water and terrain LOD moves with the camera, fix it like in the wanderer.
 - Pause previews drawing of main window when a dialog is opened.
 - Interrupt preview chunk renderings that will be discarded at commit, or that are no more visible.
diff --git a/gui_qt/wandererchunk.cpp b/gui_qt/wandererchunk.cpp
index 3d06160..fa1ff8f 100644
--- a/gui_qt/wandererchunk.cpp
+++ b/gui_qt/wandererchunk.cpp
@@ -1,7 +1,5 @@
 #include "wandererchunk.h"
 
-#include <math.h>
-#include <stdlib.h>
 #include <QMutex>
 #include <QImage>
 #include <QColor>
@@ -13,23 +11,29 @@ WandererChunk::WandererChunk(double x, double z, double size)
 {
     _startx = x;
     _startz = z;
-    _dirty = true;
+    _dirty = 3;
     _chunksize = size;
-    _nbsubchunks = 4;
+    _nbsubchunks = 8;
     _subchunksize = size / (double)_nbsubchunks;
-    _texture = new QImage(4, 4, QImage::Format_ARGB32);
+    _texture = new QImage(1, 1, QImage::Format_ARGB32);
     _texture->fill(QColor(0, 200, 0));
     _texture_id = 0;
     _need_texture_upload = true;
-    _heightmap = (double*)malloc(sizeof(double) * (_nbsubchunks + 1) * (_nbsubchunks + 1));
-    //_heightmap[0] = _heightmap[1] = _heightmap[2] = _heightmap[3] = toolsRandom();
+    _heightmap = new double[(_nbsubchunks + 1) * (_nbsubchunks + 1)];
+    for (int j = 0; j <= _nbsubchunks; j++)
+    {
+        for (int i = 0; i <= _nbsubchunks; i++)
+        {
+            _heightmap[j * (_nbsubchunks + 1) + i] = -100.0;
+        }
+    }
 }
 
 WandererChunk::~WandererChunk()
 {
     _lock.lock();
     delete _texture;
-    free(_heightmap);
+    delete [] _heightmap;
     _lock.unlock();
 }
 
@@ -56,7 +60,6 @@ void WandererChunk::render(QGLWidget* widget)
         glBegin(GL_QUAD_STRIP);
         for (int i = 0; i <= _nbsubchunks; i++)
         {
-            glColor3f(1.0, 1.0, 1.0);
             glTexCoord2d(tsize * (double)i, 1.0 - tsize * (double)j);
             glVertex3d(_startx + _subchunksize * (double)i, _heightmap[j * (_nbsubchunks + 1) + i], _startz + _subchunksize * (double)j);
             glTexCoord2d(tsize * (double)i, 1.0 - tsize * (double)(j + 1));
@@ -68,37 +71,92 @@ void WandererChunk::render(QGLWidget* widget)
     _lock.unlock();
 }
 
-void WandererChunk::maintain(Renderer* renderer)
+bool WandererChunk::maintain(Renderer* renderer)
 {
-    _lock.lock();
-    
+    _lock_dirty.lock();
     if (_dirty)
     {
-        _dirty = false;
+        int dirty = _dirty--;
+        _lock_dirty.unlock();
         
         // Compute heightmap
-        for (int j = 0; j <= _nbsubchunks; j++)
+        if (dirty == 3)
         {
-            for (int i = 0; i <= _nbsubchunks; i++)
+            double* new_heightmap = new double[(_nbsubchunks + 1) * (_nbsubchunks + 1)];
+            for (int j = 0; j <= _nbsubchunks; j++)
             {
-                _heightmap[j * (_nbsubchunks + 1) + i] = renderer->getTerrainHeight(renderer, _startx + _subchunksize * (double)i, _startz + _subchunksize * (double)j);
+                for (int i = 0; i <= _nbsubchunks; i++)
+                {
+                    new_heightmap[j * (_nbsubchunks + 1) + i] = renderer->getTerrainHeight(renderer, _startx + _subchunksize * (double)i, _startz + _subchunksize * (double)j);
+                }
             }
+            _lock.lock();
+            delete [] _heightmap;
+            _heightmap = new_heightmap;
+            _lock.unlock();
+        }
+
+        // Compute low-res texture
+        if (dirty == 2)
+        {
+            int texture_size = 4;
+            double step_size = _chunksize / (double)(texture_size - 1);
+            QImage* new_image = new QImage(texture_size, texture_size, QImage::Format_ARGB32);
+            for (int j = 0; j < texture_size; j++)
+            {
+                for (int i = 0; i < texture_size; i++)
+                {
+                    Vector3 location = {_startx + step_size * (double)i, 0.0, _startz + step_size * (double)j};
+                    Color color = renderer->applyTextures(renderer, location, step_size);
+                    new_image->setPixel(i, j, colorTo32BitRGBA(&color));
+                }
+            }
+            _lock.lock();
+            delete _texture;
+            _texture = new_image;
+            _need_texture_upload = true;
+            _lock.unlock();
+        }
+
+        // Compute texture
+        if (dirty == 1)
+        {
+            int texture_size = 32;
+            double step_size = _chunksize / (double)(texture_size - 1);
+            QImage* new_image = new QImage(texture_size, texture_size, QImage::Format_ARGB32);
+            for (int j = 0; j < texture_size; j++)
+            {
+                for (int i = 0; i < texture_size; i++)
+                {
+                    Vector3 location = {_startx + step_size * (double)i, 0.0, _startz + step_size * (double)j};
+                    Color color = renderer->applyTextures(renderer, location, step_size);
+                    new_image->setPixel(i, j, colorTo32BitRGBA(&color));
+                }
+            }
+            _lock.lock();
+            delete _texture;
+            _texture = new_image;
+            _need_texture_upload = true;
+            _lock.unlock();
         }
         
-        // Compute texture
-        int texture_size = 4;
-        double step_size = _chunksize / (double)(texture_size - 1);
-        for (int j = 0; j < texture_size; j++)
-        {
-            for (int i = 0; i < texture_size; i++)
-            {
-                Vector3 location = {_startx + step_size * (double)i, 0.0, _startz + step_size * (double)j};
-                Color color = renderer->applyTextures(renderer, location, step_size);
-                _texture->setPixel(i, j, colorTo32BitRGBA(&color));
-            }
-        }
-        _need_texture_upload = true;
+        return true;
+    }
+    else
+    {
+        _lock_dirty.unlock();
+        
+        return false;
     }
-    
-    _lock.unlock();
+}
+
+Vector3 WandererChunk::getCenter()
+{
+    Vector3 result;
+    
+    result.x = _startz + _chunksize / 2.0;
+    result.y = 0.0;
+    result.z = _startz + _chunksize / 2.0;
+    
+    return result;
 }
diff --git a/gui_qt/wandererchunk.h b/gui_qt/wandererchunk.h
index f071c69..04efa5f 100644
--- a/gui_qt/wandererchunk.h
+++ b/gui_qt/wandererchunk.h
@@ -12,14 +12,17 @@ public:
     WandererChunk(double x, double z, double size);
     ~WandererChunk();
     
-    void maintain(Renderer* renderer);
+    bool maintain(Renderer* renderer);
     void render(QGLWidget* widget);
     
+    Vector3 getCenter();
+    
 private:
     QMutex _lock;
+    QMutex _lock_dirty;
     double _startx;
     double _startz;
-    bool _dirty;
+    int _dirty;
     double _chunksize;
     double _subchunksize;
     int _nbsubchunks;
diff --git a/gui_qt/widgetwanderer.cpp b/gui_qt/widgetwanderer.cpp
index 65948ee..79723a8 100644
--- a/gui_qt/widgetwanderer.cpp
+++ b/gui_qt/widgetwanderer.cpp
@@ -5,7 +5,45 @@
 #include <QTime>
 #include <math.h>
 #include <GL/glu.h>
+#include <QThread>
 #include "../lib_paysages/scenery.h"
+#include "../lib_paysages/euclid.h"
+
+class ChunkMaintenanceThread:public QThread
+{
+public:
+    ChunkMaintenanceThread(WidgetWanderer* wanderer)
+    {
+        _wanderer = wanderer;
+        _running = true;
+    }
+
+    void askStop()
+    {
+        _running = false;
+    }
+    
+    static inline void usleep(unsigned long us)
+    {
+        QThread::usleep(us);
+    }
+    
+protected:
+    void run()
+    {
+        while (_running)
+        {
+            _wanderer->performChunksMaintenance();
+            QThread::usleep(10000);
+        }
+    }
+    
+private:
+    bool _running;
+    WidgetWanderer* _wanderer;
+};
+
+static QVector<ChunkMaintenanceThread*> _threads;
 
 WidgetWanderer::WidgetWanderer(QWidget *parent, CameraDefinition* camera):
     QGLWidget(parent)
@@ -18,20 +56,28 @@ WidgetWanderer::WidgetWanderer(QWidget *parent, CameraDefinition* camera):
 
     _water = waterCreateDefinition();
     sceneryGetWater(&_water);
+    _sky = skyCreateDefinition();
+    sceneryGetSky(&_sky);
     
     _renderer = sceneryCreateStandardRenderer();
+    _updated = false;
 
     int chunks = 16;
-    double size = 30.0;
+    double size = 150.0;
     double chunksize = size / (double)chunks;
     double start = -size / 2.0;
     for (int i = 0; i < chunks; i++)
     {
         for (int j = 0; j < chunks; j++)
         {
-            _chunks.append(new WandererChunk(start + chunksize * (double)i, start + chunksize * (double)j, chunksize));
+            WandererChunk* chunk = new WandererChunk(start + chunksize * (double)i, start + chunksize * (double)j, chunksize);
+            _chunks.append(chunk);
+            _updateQueue.append(chunk);
         }
     }
+
+    startThreads();
+    startTimer(1000);
     
     _average_frame_time = 0.05;
     _quality = 3;
@@ -41,6 +87,8 @@ WidgetWanderer::WidgetWanderer(QWidget *parent, CameraDefinition* camera):
 
 WidgetWanderer::~WidgetWanderer()
 {
+    stopThreads();
+    
     for (int i = 0; i < _chunks.count(); i++)
     {
         delete _chunks[i];
@@ -48,6 +96,72 @@ WidgetWanderer::~WidgetWanderer()
     waterDeleteDefinition(&_water);
 }
 
+void WidgetWanderer::startThreads()
+{
+    int nbcore;
+    
+    _alive = true;
+    
+    nbcore = QThread::idealThreadCount() - 1;
+    if (nbcore < 1)
+    {
+        nbcore = 1;
+    }
+    
+    for (int i = 0; i < nbcore; i++)
+    {
+        _threads.append(new ChunkMaintenanceThread(this));
+    }
+    for (int i = 0; i < _threads.count(); i++)
+    {
+        _threads[i]->start();
+    }
+}
+
+void WidgetWanderer::stopThreads()
+{
+    for (int i = 0; i < _threads.count(); i++)
+    {
+        _threads[i]->askStop();
+    }
+    _alive = false;
+    for (int i = 0; i < _threads.count(); i++)
+    {
+        _threads[i]->wait();
+    }
+}
+
+void WidgetWanderer::performChunksMaintenance()
+{
+    WandererChunk* chunk;
+    
+    _lock_chunks.lock();
+    if (_updateQueue.count() > 0)
+    {
+        chunk = _updateQueue.takeFirst();
+        _lock_chunks.unlock();
+    }
+    else
+    {
+        _lock_chunks.unlock();
+        return;
+    }
+    
+    if (chunk->maintain(&_renderer))
+    {
+        if (!_alive)
+        {
+            return;
+        }
+
+        _updated = true;
+    }
+    
+    _lock_chunks.lock();
+    _updateQueue.append(chunk);
+    _lock_chunks.unlock();
+}
+
 void WidgetWanderer::resetCamera()
 {
     cameraCopyDefinition(_base_camera, &_current_camera);
@@ -189,9 +303,18 @@ void WidgetWanderer::wheelEvent(QWheelEvent* event)
     event->accept();
 }
 
+void WidgetWanderer::timerEvent(QTimerEvent *event)
+{
+    if (_updated)
+    {
+        _updated = false;
+        updateGL();
+    }
+}
+
 void WidgetWanderer::initializeGL()
 {
-    glClearColor(0.4, 0.7, 0.8, 0.0);
+    glClearColor(0.0, 0.0, 0.0, 0.0);
 
     glDisable(GL_LIGHTING);
 
@@ -208,7 +331,7 @@ void WidgetWanderer::initializeGL()
     glLineWidth(1.0);
 
     glDisable(GL_FOG);
-    
+
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 }
 
@@ -230,6 +353,11 @@ void WidgetWanderer::paintGL()
     QTime start_time;
     double frame_time;
     
+    if (_current_camera.location.y > 30.0)
+    {
+        _current_camera.location.y = 30.0;
+    }
+    
     cameraValidateDefinition(&_current_camera, 1);
     
     start_time = QTime::currentTime();
@@ -238,13 +366,27 @@ void WidgetWanderer::paintGL()
     glLoadIdentity();
     gluLookAt(_current_camera.location.x, _current_camera.location.y, _current_camera.location.z, _current_camera.target.x, _current_camera.target.y, _current_camera.target.z, _current_camera.up.x, _current_camera.up.y, _current_camera.up.z);
 
+    // Background
+    Color zenith_color = skyGetZenithColor(&_sky);
+    glClearColor(zenith_color.r, zenith_color.g, zenith_color.b, 0.0);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+    // Render sun
+    Vector3 sun_location = v3Add(_current_camera.location, v3Scale(skyGetSunDirection(&_sky), 500.0));
+    Color sun_color = skyGetSunColor(&_sky);
+    glDisable(GL_TEXTURE);
+    glDisable(GL_TEXTURE_2D);
+    glColor3f(sun_color.r, sun_color.g, sun_color.b);
+    glPointSize(15.0 * _sky.sun_radius / 0.02);
+    glEnable(GL_POINT_SMOOTH);
+    glBegin(GL_POINTS);
+    glVertex3f(sun_location.x, sun_location.y, sun_location.z);
+    glEnd();
 
     // Render water
     glDisable(GL_TEXTURE);
     glDisable(GL_TEXTURE_2D);
-    glColor3f(0.0, 0.0, 1.0);
+    glColor3f(_water.material.base.r, _water.material.base.g, _water.material.base.b);
     glBegin(GL_QUADS);
     glVertex3f(_current_camera.location.x - 500.0, _water.height, _current_camera.location.z - 500.0);
     glVertex3f(_current_camera.location.x - 500.0, _water.height, _current_camera.location.z + 500.0);
@@ -257,8 +399,7 @@ void WidgetWanderer::paintGL()
     glEnable(GL_TEXTURE_2D);
     for (int i = 0; i < _chunks.count(); i++)
     {
-        _chunks[i]->maintain(&_renderer);
-        
+        glColor3f(1.0, 1.0, 1.0);
         _chunks[i]->render(this);
     }
     
diff --git a/gui_qt/widgetwanderer.h b/gui_qt/widgetwanderer.h
index 556f48b..7e29ec7 100644
--- a/gui_qt/widgetwanderer.h
+++ b/gui_qt/widgetwanderer.h
@@ -3,11 +3,10 @@
 
 #include <QGLWidget>
 #include "wandererchunk.h"
-#include "../lib_paysages/atmosphere.h"
 #include "../lib_paysages/camera.h"
-#include "../lib_paysages/terrain.h"
 #include "../lib_paysages/water.h"
 #include "../lib_paysages/renderer.h"
+#include "../lib_paysages/sky.h"
 
 class WidgetWanderer : public QGLWidget
 {
@@ -15,6 +14,8 @@ class WidgetWanderer : public QGLWidget
 public:
     WidgetWanderer(QWidget* parent, CameraDefinition* camera);
     ~WidgetWanderer();
+    
+    void performChunksMaintenance();
 
 public slots:
     void resetCamera();
@@ -25,20 +26,29 @@ protected:
     void mousePressEvent(QMouseEvent* event);
     void mouseMoveEvent(QMouseEvent* event);
     void wheelEvent(QWheelEvent* event);
+    void timerEvent(QTimerEvent *event);
 
     void initializeGL();
     void resizeGL(int w, int h);
     void paintGL();
-
+    
 private:
+    void startThreads();
+    void stopThreads();
+    
     CameraDefinition _current_camera;
     CameraDefinition* _base_camera;
     
     Renderer _renderer;
+    bool _updated;
     
     QVector<WandererChunk*> _chunks;
+    QList<WandererChunk*> _updateQueue;
+    bool _alive;
+    QMutex _lock_chunks;
 
     WaterDefinition _water;
+    SkyDefinition _sky;
     
     double _average_frame_time;
     int _quality;
diff --git a/lib_paysages/sky.c b/lib_paysages/sky.c
index 7f1c140..b46f77d 100644
--- a/lib_paysages/sky.c
+++ b/lib_paysages/sky.c
@@ -143,14 +143,11 @@ int skyGetLights(SkyDefinition* sky, LightDefinition* lights, int max_lights)
 
 Color skyGetColor(SkyDefinition* definition, Renderer* renderer, Vector3 eye, Vector3 look)
 {
-    double sun_angle, dist;
+    double dist;
     Vector3 sun_position;
     Color sun_color, sky_color;
 
-    sun_angle = (definition->daytime + 0.75) * M_PI * 2.0;
-    sun_position.x = cos(sun_angle);
-    sun_position.y = sin(sun_angle);
-    sun_position.z = 0.0;
+    sun_position = skyGetSunDirection(definition);
 
     look = v3Normalize(look);
     dist = v3Norm(v3Sub(look, sun_position));
@@ -269,3 +266,23 @@ void skyRender(SkyDefinition* definition, Renderer* renderer)
         }
     }
 }
+
+Vector3 skyGetSunDirection(SkyDefinition* definition)
+{
+    Vector3 result;
+    double sun_angle = (definition->daytime + 0.75) * M_PI * 2.0;
+    result.x = cos(sun_angle);
+    result.y = sin(sun_angle);
+    result.z = 0.0;
+    return result;
+}
+
+Color skyGetSunColor(SkyDefinition* definition)
+{
+    return colorGradationGet(definition->sun_color, definition->daytime);
+}
+
+Color skyGetZenithColor(SkyDefinition* definition)
+{
+    return colorGradationGet(definition->zenith_color, definition->daytime);
+}
diff --git a/lib_paysages/sky.h b/lib_paysages/sky.h
index 299f3b3..e966a79 100644
--- a/lib_paysages/sky.h
+++ b/lib_paysages/sky.h
@@ -35,6 +35,9 @@ void skyValidateDefinition(SkyDefinition* definition);
 int skyGetLights(SkyDefinition* sky, LightDefinition* lights, int max_lights);
 Color skyGetColor(SkyDefinition* definition, Renderer* renderer, Vector3 eye, Vector3 look);
 void skyRender(SkyDefinition* definition, Renderer* renderer);
+Vector3 skyGetSunDirection(SkyDefinition* definition);
+Color skyGetSunColor(SkyDefinition* definition);
+Color skyGetZenithColor(SkyDefinition* definition);
 
 #ifdef __cplusplus
 }