diff --git a/TODO b/TODO
index 4999d07..82c883d 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,6 @@
 Technology Preview 2 :
 - Add initial terrain offset so that the (0,0) coordinates are above water.
+- Use water height as 0.0 (offset the terrain).
 - Finalize lighting/clouds refactoring
    => Restore cloud lighting
    => Improve cloud rendering precision (and beware of precision discontinuity when rendering clouds in front of ground (shorter distance)).
diff --git a/src/basics/Color.h b/src/basics/Color.h
index 78ed134..594dd4c 100644
--- a/src/basics/Color.h
+++ b/src/basics/Color.h
@@ -10,7 +10,7 @@ class Color
 {
 public:
     Color();
-    Color(double r, double g, double b, double a);
+    Color(double r, double g, double b, double a=1.0);
 
     void save(PackStream* stream) const;
     void load(PackStream* stream);
diff --git a/src/definition/CloudLayerDefinition.cpp b/src/definition/CloudLayerDefinition.cpp
index 9f5d115..eb4ce25 100644
--- a/src/definition/CloudLayerDefinition.cpp
+++ b/src/definition/CloudLayerDefinition.cpp
@@ -8,20 +8,14 @@
 CloudLayerDefinition::CloudLayerDefinition(BaseDefinition* parent):
     BaseDefinition(parent)
 {
-    _coverage_by_altitude = new Curve;
-    _coverage_noise = new NoiseGenerator();
-    _shape_noise = new NoiseGenerator();
-    _edge_noise = new NoiseGenerator();
-    material = new SurfaceMaterial;
+    type = CIRRUS;
+    altitude = 0.5;
+    scaling = 0.5;
+    coverage = 0.5;
 }
 
 CloudLayerDefinition::~CloudLayerDefinition()
 {
-    delete _coverage_by_altitude;
-    delete _coverage_noise;
-    delete _shape_noise;
-    delete _edge_noise;
-    delete material;
 }
 
 CloudLayerDefinition* CloudLayerDefinition::newCopy(const CloudLayerDefinition& other, BaseDefinition* parent)
@@ -45,21 +39,9 @@ void CloudLayerDefinition::save(PackStream* stream) const
     int clouds_type = (int)type;
 
     stream->write(&clouds_type);
-    stream->write(&lower_altitude);
-    stream->write(&thickness);
-    _coverage_by_altitude->save(stream);
-    _coverage_noise->save(stream);
-    _shape_noise->save(stream);
-    _edge_noise->save(stream);
-    materialSave(stream, material);
-    stream->write(&hardness);
-    stream->write(&transparencydepth);
-    stream->write(&lighttraversal);
-    stream->write(&minimumlight);
-    stream->write(&shape_scaling);
-    stream->write(&edge_scaling);
-    stream->write(&edge_length);
-    stream->write(&base_coverage);
+    stream->write(&altitude);
+    stream->write(&scaling);
+    stream->write(&coverage);
 }
 
 void CloudLayerDefinition::load(PackStream* stream)
@@ -70,21 +52,9 @@ void CloudLayerDefinition::load(PackStream* stream)
 
     stream->read(&clouds_type);
     type = (CloudsType)clouds_type;
-    stream->read(&lower_altitude);
-    stream->read(&thickness);
-    _coverage_by_altitude->load(stream);
-    _coverage_noise->load(stream);
-    _shape_noise->load(stream);
-    _edge_noise->load(stream);
-    materialLoad(stream, material);
-    stream->read(&hardness);
-    stream->read(&transparencydepth);
-    stream->read(&lighttraversal);
-    stream->read(&minimumlight);
-    stream->read(&shape_scaling);
-    stream->read(&edge_scaling);
-    stream->read(&edge_length);
-    stream->read(&base_coverage);
+    stream->read(&altitude);
+    stream->read(&scaling);
+    stream->read(&coverage);
 
     validate();
 }
@@ -96,168 +66,15 @@ void CloudLayerDefinition::copy(BaseDefinition* _destination) const
     CloudLayerDefinition* destination = (CloudLayerDefinition*)_destination;
 
     destination->type = type;
-    destination->lower_altitude = lower_altitude;
-    destination->thickness = thickness;
-    _coverage_by_altitude->copy(destination->_coverage_by_altitude);
-    _coverage_noise->copy(destination->_coverage_noise);
-    _shape_noise->copy(destination->_shape_noise);
-    _edge_noise->copy(destination->_edge_noise);
-    *destination->material = *material;
-    destination->hardness = hardness;
-    destination->transparencydepth = transparencydepth;
-    destination->lighttraversal = lighttraversal;
-    destination->minimumlight = minimumlight;
-    destination->shape_scaling = shape_scaling;
-    destination->edge_scaling = edge_scaling;
-    destination->edge_length = edge_length;
-    destination->base_coverage = base_coverage;
+    destination->altitude = altitude;
+    destination->scaling = scaling;
+    destination->coverage = coverage;
 }
 
 void CloudLayerDefinition::validate()
 {
-    if (shape_scaling < 0.0001)
+    if (scaling < 0.1)
     {
-        shape_scaling = 0.00001;
+        scaling = 0.1;
     }
-    if (edge_scaling < 0.0001)
-    {
-        edge_scaling = 0.00001;
-    }
-
-    _coverage_by_altitude->clear();
-    _shape_noise->clearLevels();
-    _edge_noise->clearLevels();
-    _coverage_noise->clearLevels();
-
-    _coverage_noise->addLevelsSimple(2, 10.0, 0.0, 1.0, 0.0);
-    _coverage_noise->addLevelsSimple(2, 1.0, 0.0, 1.0, 0.0);
-    _coverage_noise->setFunctionParams(NOISE_FUNCTION_NAIVE, 0.0, 0.0);
-    switch (type)
-    {
-        case CLOUDS_TYPE_CIRRUS:
-            _coverage_by_altitude->addPoint(0.0, 0.0);
-            _coverage_by_altitude->addPoint(0.5, 1.0);
-            _coverage_by_altitude->addPoint(1.0, 0.0);
-            _shape_noise->addLevelsSimple(3, 1.0, 0.0, 1.0, 0.5);
-            _shape_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, 0.0, 0.0);
-            _edge_noise->addLevelsSimple(4, 1.0, -0.5, 0.5, 0.5);
-            _edge_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, -0.2, 0.0);
-            break;
-        case CLOUDS_TYPE_CUMULUS:
-            _coverage_by_altitude->addPoint(0.0, 0.0);
-            _coverage_by_altitude->addPoint(0.1, 1.0);
-            _coverage_by_altitude->addPoint(0.4, 0.8);
-            _coverage_by_altitude->addPoint(0.7, 1.0);
-            _coverage_by_altitude->addPoint(1.0, 0.0);
-            _shape_noise->addLevelsSimple(7, 1.0, 0.0, 1.0, 0.5);
-            _shape_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, 0.4, 0.0);
-            _edge_noise->addLevelsSimple(4, 1.0, -0.5, 0.5, 0.5);
-            _edge_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, 0.8, 0.0);
-            break;
-        case CLOUDS_TYPE_STRATOCUMULUS:
-            _coverage_by_altitude->addPoint(0.0, 0.0);
-            _coverage_by_altitude->addPoint(0.2, 1.0);
-            _coverage_by_altitude->addPoint(0.5, 1.0);
-            _coverage_by_altitude->addPoint(1.0, 0.0);
-            _shape_noise->addLevelsSimple(4, 1.0, 0.0, 1.0, 0.5);
-            _shape_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, 0.3, 0.0);
-            _edge_noise->addLevelsSimple(6, 1.0, -0.5, 0.5, 0.5);
-            _edge_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, 0.5, 0.0);
-            break;
-        case CLOUDS_TYPE_STRATUS:
-            _coverage_by_altitude->addPoint(0.0, 0.0);
-            _coverage_by_altitude->addPoint(0.2, 1.0);
-            _coverage_by_altitude->addPoint(0.8, 1.0);
-            _coverage_by_altitude->addPoint(1.0, 0.0);
-            _shape_noise->addLevelsSimple(3, 1.0, 0.0, 1.0, 0.5);
-            _shape_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, -0.3, 0.0);
-            _edge_noise->addLevelsSimple(4, 1.0, -0.5, 0.5, 0.5);
-            _edge_noise->setFunctionParams(NOISE_FUNCTION_SIMPLEX, -0.5, 0.0);
-            break;
-        default:
-            break;
-    }
-
-    _coverage_noise->normalizeAmplitude(-1.0, 3.0, 0);
-    _shape_noise->normalizeAmplitude(-0.5, 0.5, 0);
-    _edge_noise->normalizeAmplitude(-0.5, 0.5, 0);
-
-    materialValidate(material);
-}
-
-void CloudLayerDefinition::applyPreset(CloudsLayerPreset preset)
-{
-    _coverage_noise->randomizeOffsets();
-    _edge_noise->randomizeOffsets();
-    _shape_noise->randomizeOffsets();
-
-    material->base = colorToHSL(colorFromValues(0.7, 0.7, 0.7, 1.0));
-
-    switch (preset)
-    {
-        case CLOUDS_LAYER_PRESET_CIRRUS:
-            type = CLOUDS_TYPE_CIRRUS;
-            lower_altitude = 25.0;
-            thickness = 2.0;
-            material->reflection = 0.4;
-            material->shininess = 0.5;
-            hardness = 0.0;
-            transparencydepth = 3.0;
-            lighttraversal = 10.0;
-            minimumlight = 0.6;
-            shape_scaling = 8.0;
-            edge_scaling = 2.0;
-            edge_length = 0.8;
-            base_coverage = 0.6;
-            break;
-        case CLOUDS_LAYER_PRESET_CUMULUS:
-            type = CLOUDS_TYPE_CUMULUS;
-            lower_altitude = 15.0;
-            thickness = 15.0;
-            material->reflection = 0.5;
-            material->shininess = 1.2;
-            hardness = 0.25;
-            transparencydepth = 1.5;
-            lighttraversal = 8.0;
-            minimumlight = 0.4;
-            shape_scaling = 20.0;
-            edge_scaling = 2.0;
-            edge_length = 0.0;
-            base_coverage = 0.7;
-            break;
-        case CLOUDS_LAYER_PRESET_STRATOCUMULUS:
-            type = CLOUDS_TYPE_STRATOCUMULUS;
-            lower_altitude = 5.0;
-            thickness = 6.0;
-            material->reflection = 0.3;
-            material->shininess = 0.8;
-            hardness = 0.25;
-            transparencydepth = 1.5;
-            lighttraversal = 7.0;
-            minimumlight = 0.4;
-            shape_scaling = 10.0;
-            edge_scaling = 0.8;
-            edge_length = 0.3;
-            base_coverage = 0.4;
-            break;
-        case CLOUDS_LAYER_PRESET_STRATUS:
-            type = CLOUDS_TYPE_STRATUS;
-            lower_altitude = 3.0;
-            thickness = 4.0;
-            material->reflection = 0.1;
-            material->shininess = 0.8;
-            hardness = 0.1;
-            transparencydepth = 3.0;
-            lighttraversal = 10.0;
-            minimumlight = 0.6;
-            shape_scaling = 8.0;
-            edge_scaling = 2.0;
-            edge_length = 1.0;
-            base_coverage = 0.4;
-            break;
-        default:
-            break;
-    }
-
-    validate();
 }
diff --git a/src/definition/CloudLayerDefinition.h b/src/definition/CloudLayerDefinition.h
index bf0b243..cae99f4 100644
--- a/src/definition/CloudLayerDefinition.h
+++ b/src/definition/CloudLayerDefinition.h
@@ -26,39 +26,23 @@ public:
 public:
     typedef enum
     {
-        CLOUDS_TYPE_CIRRUS,
-        CLOUDS_TYPE_CUMULUS,
-        CLOUDS_TYPE_STRATOCUMULUS,
-        CLOUDS_TYPE_STRATUS
+        STRATUS,
+        NIMBOSTRATUS,
+        CUMULUS,
+        STRATOCUMULUS,
+        ALTOCUMULUS,
+        ALTOSTRATUS,
+        CUMULONIMBUS,
+        CIRROCUMULUS,
+        CIRROSTRATUS,
+        CIRRUS
     } CloudsType;
 
-    typedef enum
-    {
-        CLOUDS_LAYER_PRESET_CIRRUS,
-        CLOUDS_LAYER_PRESET_CUMULUS,
-        CLOUDS_LAYER_PRESET_STRATOCUMULUS,
-        CLOUDS_LAYER_PRESET_STRATUS
-    } CloudsLayerPreset;
-    void applyPreset(CloudsLayerPreset preset);
-
 public:
     CloudsType type;
-    double lower_altitude;
-    double thickness;
-    double base_coverage;
-    double shape_scaling;
-    double edge_scaling;
-    double edge_length;
-    SurfaceMaterial* material;
-    double hardness;
-    double transparencydepth;
-    double lighttraversal;
-    double minimumlight;
-
-    Curve* _coverage_by_altitude;
-    NoiseGenerator* _coverage_noise;
-    NoiseGenerator* _shape_noise;
-    NoiseGenerator* _edge_noise;
+    double altitude;
+    double scaling;
+    double coverage;
 };
 
 }
diff --git a/src/definition/CloudsDefinition.cpp b/src/definition/CloudsDefinition.cpp
index e176cb5..0608479 100644
--- a/src/definition/CloudsDefinition.cpp
+++ b/src/definition/CloudsDefinition.cpp
@@ -19,8 +19,8 @@ void CloudsDefinition::applyPreset(CloudsPreset preset)
     if (preset == CLOUDS_PRESET_PARTLY_CLOUDY)
     {
         CloudLayerDefinition* layer = new CloudLayerDefinition(this);
-        layer->applyPreset(CloudLayerDefinition::CLOUDS_LAYER_PRESET_CIRRUS);
-        layer->setName("Cirrus");
+        layer->type = CloudLayerDefinition::STRATOCUMULUS;
+        layer->setName("Strato-cumulus");
         addLayer(layer);
     }
 }
diff --git a/src/interface/desktop/formclouds.cpp b/src/interface/desktop/formclouds.cpp
index 4f4b9f6..627041e 100644
--- a/src/interface/desktop/formclouds.cpp
+++ b/src/interface/desktop/formclouds.cpp
@@ -14,11 +14,6 @@
 FormClouds::FormClouds(QWidget *parent):
     BaseFormLayer(parent)
 {
-    addAutoPreset(tr("Cirrus"));
-    addAutoPreset(tr("Cumulus"));
-    addAutoPreset(tr("Stratocumulus"));
-    addAutoPreset(tr("Stratus"));
-
     _definition = new CloudsDefinition(NULL);
     _layer = new CloudLayerDefinition(NULL);
 
@@ -33,17 +28,9 @@ FormClouds::FormClouds(QWidget *parent):
     _previewColor->setRenderer(_previewColorRenderer);
 
     addInputEnum(tr("Clouds model"), (int*)&_layer->type, QStringList() << tr("Cirrus") << tr("Cumulus") << tr("Stratocumulus") << tr("Stratus"));
-    addInputDouble(tr("Lower altitude"), &_layer->lower_altitude, -10.0, 50.0, 0.5, 5.0);
-    addInputDouble(tr("Layer thickness"), &_layer->thickness, 0.0, 20.0, 0.1, 1.0);
-    addInputDouble(tr("Max coverage"), &_layer->base_coverage, 0.0, 1.0, 0.01, 0.1);
-    addInputDouble(tr("Shape scaling"), &_layer->shape_scaling, 3.0, 30.0, 0.3, 3.0);
-    addInputDouble(tr("Edge scaling"), &_layer->edge_scaling, 0.5, 5.0, 0.05, 0.5);
-    addInputDouble(tr("Edge length"), &_layer->edge_length, 0.0, 1.0, 0.01, 0.1);
-    addInputMaterial(tr("Material"), _layer->material);
-    addInputDouble(tr("Hardness to light"), &_layer->hardness, 0.0, 1.0, 0.01, 0.1);
-    addInputDouble(tr("Transparency depth"), &_layer->transparencydepth, 0.0, 10.0, 0.1, 1.0);
-    addInputDouble(tr("Light traversal depth"), &_layer->lighttraversal, 0.0, 10.0, 0.1, 1.0);
-    addInputDouble(tr("Minimum lighting"), &_layer->minimumlight, 0.0, 1.0, 0.01, 0.1);
+    addInputDouble(tr("Lower altitude"), &_layer->altitude, 0.0, 1.0, 0.01, 0.1);
+    addInputDouble(tr("Scaling"), &_layer->scaling, 0.0, 1.0, 0.01, 0.1);
+    addInputDouble(tr("Coverage"), &_layer->coverage, 0.0, 1.0, 0.01, 0.1);
 
     setLayers(_definition);
 }
@@ -81,9 +68,3 @@ void FormClouds::layerWriteCurrentTo(void* layer_definition)
 {
     _layer->copy((CloudLayerDefinition*)layer_definition);
 }
-
-void FormClouds::autoPresetSelected(int preset)
-{
-    _layer->applyPreset((CloudLayerDefinition::CloudsLayerPreset)preset);
-    BaseForm::autoPresetSelected(preset);
-}
diff --git a/src/interface/desktop/formclouds.h b/src/interface/desktop/formclouds.h
index de4118c..daebcd0 100644
--- a/src/interface/desktop/formclouds.h
+++ b/src/interface/desktop/formclouds.h
@@ -21,7 +21,6 @@ public slots:
 protected:
     virtual void layerReadCurrentFrom(void* layer_definition);
     virtual void layerWriteCurrentTo(void* layer_definition);
-    virtual void autoPresetSelected(int preset);
 
 private:
     CloudsDefinition* _definition;
diff --git a/src/render/preview/CloudsAspectPreviewRenderer.cpp b/src/render/preview/CloudsAspectPreviewRenderer.cpp
index 46fc362..3d460e5 100644
--- a/src/render/preview/CloudsAspectPreviewRenderer.cpp
+++ b/src/render/preview/CloudsAspectPreviewRenderer.cpp
@@ -30,7 +30,7 @@ static void _getLightingStatus(Renderer*, LightStatus* status, Vector3, int)
 
 static double _getDensity(Renderer*, CloudLayerDefinition* layer, Vector3 location)
 {
-    double distance = 2.0 * v3Norm(location) / layer->thickness;
+    double distance = 2.0 * v3Norm(location) / layer->scaling;
     if (distance > 1.0)
     {
         return 0.0;
@@ -75,8 +75,7 @@ void CloudsAspectPreviewRenderer::updateEvent()
     CloudLayerDefinition* preview_layer = getScenery()->getClouds()->getCloudLayer(0);
     layer->copy(preview_layer);
 
-    preview_layer->thickness = preview_layer->shape_scaling;
-    preview_layer->lower_altitude = -preview_layer->thickness / 2.0;
+    preview_layer->altitude = -preview_layer->scaling / 2.0;
     preview_layer->validate();
 
     prepare();
@@ -89,7 +88,7 @@ void CloudsAspectPreviewRenderer::updateEvent()
 Color CloudsAspectPreviewRenderer::getColor2D(double x, double y, double)
 {
     Vector3 start, end;
-    double thickness = layer->thickness;
+    double thickness = layer->scaling;
 
     start.x = x * thickness * 0.5;
     start.z = y * thickness * 0.5;
diff --git a/src/render/software/BaseCloudLayerRenderer.cpp b/src/render/software/BaseCloudLayerRenderer.cpp
index 8b79a66..05f28a3 100644
--- a/src/render/software/BaseCloudLayerRenderer.cpp
+++ b/src/render/software/BaseCloudLayerRenderer.cpp
@@ -1,6 +1,6 @@
 #include "BaseCloudLayerRenderer.h"
 
-#include "CloudLayerDefinition.h"
+#include "clouds/BaseCloudsModel.h"
 
 BaseCloudLayerRenderer::BaseCloudLayerRenderer(SoftwareRenderer* parent):
     parent(parent)
@@ -12,67 +12,65 @@ BaseCloudLayerRenderer::~BaseCloudLayerRenderer()
 
 }
 
-double BaseCloudLayerRenderer::getDensity(CloudLayerDefinition *, const Vector3 &)
-{
-    return 0.0;
-}
-
-Color BaseCloudLayerRenderer::getColor(CloudLayerDefinition *, const Vector3 &, const Vector3 &)
+Color BaseCloudLayerRenderer::getColor(BaseCloudsModel *, const Vector3 &, const Vector3 &)
 {
     return COLOR_TRANSPARENT;
 }
 
-bool BaseCloudLayerRenderer::alterLight(CloudLayerDefinition *, LightDefinition *, const Vector3 &, const Vector3 &)
+bool BaseCloudLayerRenderer::alterLight(BaseCloudsModel *, LightDefinition *, const Vector3 &, const Vector3 &)
 {
     return false;
 }
 
-bool BaseCloudLayerRenderer::optimizeSearchLimits(CloudLayerDefinition *layer, Vector3 *start, Vector3 *end)
+bool BaseCloudLayerRenderer::optimizeSearchLimits(BaseCloudsModel *model, Vector3 *start, Vector3 *end)
 {
     Vector3 diff;
+    double min_altitude, max_altitude;
 
-    if (start->y > layer->lower_altitude + layer->thickness)
+    model->getAltitudeRange(&min_altitude, &max_altitude);
+
+    if (start->y > max_altitude)
     {
-        if (end->y >= layer->lower_altitude + layer->thickness)
+        if (end->y >= max_altitude)
         {
             return false;
         }
         else
         {
             diff = v3Sub(*end, *start);
-            *start = v3Add(*start, v3Scale(diff, (layer->lower_altitude + layer->thickness - start->y) / diff.y));
-            if (end->y < layer->lower_altitude)
+            *start = v3Add(*start, v3Scale(diff, (max_altitude - start->y) / diff.y));
+            if (end->y < min_altitude)
             {
-                *end = v3Add(*end, v3Scale(diff, (layer->lower_altitude - end->y) / diff.y));
+                *end = v3Add(*end, v3Scale(diff, (min_altitude - end->y) / diff.y));
             }
         }
     }
-    else if (start->y < layer->lower_altitude)
+    else if (start->y < min_altitude)
     {
-        if (end->y <= layer->lower_altitude)
+        if (end->y <= min_altitude)
         {
             return false;
         }
         else
         {
             diff = v3Sub(*end, *start);
-            *start = v3Add(*start, v3Scale(diff, (layer->lower_altitude - start->y) / diff.y));
-            if (end->y >= layer->lower_altitude + layer->thickness)
+            *start = v3Add(*start, v3Scale(diff, (min_altitude - start->y) / diff.y));
+            if (end->y >= max_altitude)
             {
-                *end = v3Add(*end, v3Scale(diff, (layer->lower_altitude + layer->thickness - end->y) / diff.y));
+                *end = v3Add(*end, v3Scale(diff, (max_altitude - end->y) / diff.y));
             }
         }
     }
     else /* start is inside layer */
     {
         diff = v3Sub(*end, *start);
-        if (end->y > layer->lower_altitude + layer->thickness)
+        if (end->y > max_altitude)
         {
-            *end = v3Add(*start, v3Scale(diff, (layer->lower_altitude + layer->thickness - start->y) / diff.y));
+            *end = v3Add(*start, v3Scale(diff, (max_altitude - start->y) / diff.y));
         }
-        else if (end->y < layer->lower_altitude)
+        else if (end->y < min_altitude)
         {
-            *end = v3Add(*start, v3Scale(diff, (layer->lower_altitude - start->y) / diff.y));
+            *end = v3Add(*start, v3Scale(diff, (min_altitude - start->y) / diff.y));
         }
     }
 
diff --git a/src/render/software/BaseCloudLayerRenderer.h b/src/render/software/BaseCloudLayerRenderer.h
index 44d250c..5b229bf 100644
--- a/src/render/software/BaseCloudLayerRenderer.h
+++ b/src/render/software/BaseCloudLayerRenderer.h
@@ -14,11 +14,10 @@ public:
     BaseCloudLayerRenderer(SoftwareRenderer* parent);
     virtual ~BaseCloudLayerRenderer();
 
-    virtual bool optimizeSearchLimits(CloudLayerDefinition *layer, Vector3 *start, Vector3 *end);
+    virtual bool optimizeSearchLimits(BaseCloudsModel *model, Vector3 *start, Vector3 *end);
 
-    virtual double getDensity(CloudLayerDefinition* layer, const Vector3 &location);
-    virtual Color getColor(CloudLayerDefinition* layer, const Vector3 &eye, const Vector3 &location);
-    virtual bool alterLight(CloudLayerDefinition* layer, LightDefinition* light, const Vector3 &eye, const Vector3 &location);
+    virtual Color getColor(BaseCloudsModel *model, const Vector3 &eye, const Vector3 &location);
+    virtual bool alterLight(BaseCloudsModel *model, LightDefinition* light, const Vector3 &eye, const Vector3 &location);
 
 protected:
     SoftwareRenderer* parent;
diff --git a/src/render/software/CloudBasicLayerRenderer.cpp b/src/render/software/CloudBasicLayerRenderer.cpp
index 5e2a56d..c2633a3 100644
--- a/src/render/software/CloudBasicLayerRenderer.cpp
+++ b/src/render/software/CloudBasicLayerRenderer.cpp
@@ -5,6 +5,8 @@
 #include "NoiseGenerator.h"
 #include "Curve.h"
 #include "AtmosphereRenderer.h"
+#include "clouds/BaseCloudsModel.h"
+#include "SurfaceMaterial.h"
 
 typedef struct
 {
@@ -18,67 +20,9 @@ CloudBasicLayerRenderer::CloudBasicLayerRenderer(SoftwareRenderer* parent):
 {
 }
 
-static inline double _standardCoverageFunc(CloudLayerDefinition* layer, Vector3 position)
+static inline double _getDistanceToBorder(BaseCloudsModel* model, Vector3 position)
 {
-    if (position.y < layer->lower_altitude || position.y > (layer->lower_altitude + layer->thickness))
-    {
-        return 0.0;
-    }
-    else
-    {
-        return layer->base_coverage * layer->_coverage_by_altitude->getValue((position.y - layer->lower_altitude) / layer->thickness);
-    }
-}
-
-static inline double _getDistanceToBorder(CloudLayerDefinition* layer, Vector3 position)
-{
-    double val;
-    double minval, maxval;
-
-    layer->_shape_noise->getRange(&minval, &maxval);
-
-    val = 0.5 * layer->_shape_noise->get3DTotal(position.x / layer->shape_scaling, position.y / layer->shape_scaling, position.z / layer->shape_scaling) / maxval;
-
-    return (val - 0.5 + _standardCoverageFunc(layer, position)) * layer->shape_scaling;
-}
-
-static inline Vector3 _getNormal(CloudLayerDefinition* layer, Vector3 position, double detail)
-{
-    Vector3 result = {0.0, 0.0, 0.0};
-    Vector3 dposition;
-    double val, dval;
-
-    val = _getDistanceToBorder(layer, position);
-
-    dposition.x = position.x + detail;
-    dposition.y = position.y;
-    dposition.z = position.z;
-    dval = val - _getDistanceToBorder(layer, dposition);
-    result.x += dval;
-
-    dposition.x = position.x - detail;
-    dval = val - _getDistanceToBorder(layer, dposition);
-    result.x -= dval;
-
-    dposition.x = position.x;
-    dposition.y = position.y + detail;
-    dval = val - _getDistanceToBorder(layer, dposition);
-    result.y += dval;
-
-    dposition.y = position.y - detail;
-    dval = val - _getDistanceToBorder(layer, dposition);
-    result.y -= dval;
-
-    dposition.y = position.y;
-    dposition.z = position.z + detail;
-    dval = val - _getDistanceToBorder(layer, dposition);
-    result.z += dval;
-
-    dposition.z = position.z - detail;
-    dval = val - _getDistanceToBorder(layer, dposition);
-    result.z -= dval;
-
-    return v3Normalize(result);
+    return model->getDensity(position);
 }
 
 /**
@@ -97,8 +41,9 @@ static inline Vector3 _getNormal(CloudLayerDefinition* layer, Vector3 position,
  * @param out_segments Allocated space to fill found segments
  * @return Number of segments found
  */
-static int _findSegments(CloudLayerDefinition* definition, SoftwareRenderer* renderer, Vector3 start, Vector3 direction, double, int max_segments, double max_inside_length, double max_total_length, double* inside_length, double* total_length, CloudSegment* out_segments)
+static int _findSegments(BaseCloudsModel* model, SoftwareRenderer* renderer, Vector3 start, Vector3 direction, double, int max_segments, double max_inside_length, double max_total_length, double* inside_length, double* total_length, CloudSegment* out_segments)
 {
+    CloudLayerDefinition* layer = model->getLayer();
     int inside, segment_count;
     double current_total_length, current_inside_length;
     double step_length, segment_length, remaining_length;
@@ -112,7 +57,7 @@ static int _findSegments(CloudLayerDefinition* definition, SoftwareRenderer* ren
     }
 
     render_precision = 15.2 - 1.5 * (double)renderer->render_quality;
-    render_precision = render_precision * definition->shape_scaling / 50.0;
+    render_precision = render_precision * layer->scaling / 50.0;
     if (render_precision > max_total_length / 10.0)
     {
         render_precision = max_total_length / 10.0;
@@ -127,7 +72,7 @@ static int _findSegments(CloudLayerDefinition* definition, SoftwareRenderer* ren
     current_inside_length = 0.0;
     segment_length = 0.0;
     walker = start;
-    noise_distance = _getDistanceToBorder(definition, start) * render_precision;
+    noise_distance = _getDistanceToBorder(model, start) * render_precision;
     inside = (noise_distance > 0.0) ? 1 : 0;
     step = v3Scale(direction, render_precision);
 
@@ -136,7 +81,7 @@ static int _findSegments(CloudLayerDefinition* definition, SoftwareRenderer* ren
         walker = v3Add(walker, step);
         step_length = v3Norm(step);
         last_noise_distance = noise_distance;
-        noise_distance = _getDistanceToBorder(definition, walker) * render_precision;
+        noise_distance = _getDistanceToBorder(model, walker) * render_precision;
         current_total_length += step_length;
 
         if (noise_distance > 0.0)
@@ -185,49 +130,16 @@ static int _findSegments(CloudLayerDefinition* definition, SoftwareRenderer* ren
                 step = v3Scale(direction, (noise_distance > -render_precision) ? render_precision : -noise_distance);
             }
         }
-    } while (inside || (walker.y >= definition->lower_altitude - 0.001 && walker.y <= (definition->lower_altitude + definition->thickness) + 0.001 && current_total_length < max_total_length && current_inside_length < max_inside_length));
+    } while (inside || (walker.y >= layer->altitude - 0.001 && walker.y <= (layer->altitude + layer->scaling) + 0.001 && current_total_length < max_total_length && current_inside_length < max_inside_length));
 
     *total_length = current_total_length;
     *inside_length = current_inside_length;
     return segment_count;
 }
 
-static Color _applyLayerLighting(CloudLayerDefinition* definition, SoftwareRenderer* renderer, Vector3 position, double)
-{
-    Vector3 normal;
-    Color col1, col2;
-
-    normal = _getNormal(definition, position, 3.0);
-    if (renderer->render_quality > 5)
-    {
-        normal = v3Add(normal, _getNormal(definition, position, 2.0));
-        normal = v3Add(normal, _getNormal(definition, position, 1.0));
-    }
-    if (renderer->render_quality > 5)
-    {
-        normal = v3Add(normal, _getNormal(definition, position, 0.5));
-    }
-    normal = v3Scale(v3Normalize(normal), definition->hardness);
-
-    // TODO Compute light filter only once
-    col1 = renderer->applyLightingToSurface(renderer, position, normal, definition->material);
-    col2 = renderer->applyLightingToSurface(renderer, position, v3Scale(normal, -1.0), definition->material);
-
-    col1.r = (col1.r + col2.r) / 2.0;
-    col1.g = (col1.g + col2.g) / 2.0;
-    col1.b = (col1.b + col2.b) / 2.0;
-    col1.a = (col1.a + col2.a) / 2.0;
-
-    return col1;
-}
-
-double CloudBasicLayerRenderer::getDensity(CloudLayerDefinition* layer, const Vector3 &location)
-{
-    return 0.0;
-}
-
-Color CloudBasicLayerRenderer::getColor(CloudLayerDefinition* layer, const Vector3 &eye, const Vector3 &location)
+Color CloudBasicLayerRenderer::getColor(BaseCloudsModel *model, const Vector3 &eye, const Vector3 &location)
 {
+    CloudLayerDefinition* layer = model->getLayer();
     int i, segment_count;
     double max_length, detail, total_length, inside_length;
     Vector3 start, end, direction;
@@ -236,7 +148,7 @@ Color CloudBasicLayerRenderer::getColor(CloudLayerDefinition* layer, const Vecto
 
     start = eye;
     end = location;
-    if (!optimizeSearchLimits(layer, &start, &end))
+    if (!optimizeSearchLimits(model, &start, &end))
     {
         return COLOR_TRANSPARENT;
     }
@@ -246,16 +158,25 @@ Color CloudBasicLayerRenderer::getColor(CloudLayerDefinition* layer, const Vecto
     direction = direction.normalize();
     result = COLOR_TRANSPARENT;
 
-    detail = parent->getPrecision(parent, start) / layer->shape_scaling;
+    detail = parent->getPrecision(parent, start) / layer->scaling;
+    double transparency_depth = layer->scaling * 0.5;
 
-    segment_count = _findSegments(layer, parent, start, direction, detail, 20, layer->transparencydepth, max_length, &inside_length, &total_length, segments);
+    segment_count = _findSegments(model, parent, start, direction, detail, 20, transparency_depth, max_length, &inside_length, &total_length, segments);
     for (i = segment_count - 1; i >= 0; i--)
     {
-        col = _applyLayerLighting(layer, parent, segments[i].start, detail);
-        col.a = (segments[i].length >= layer->transparencydepth) ? 1.0 : (segments[i].length / layer->transparencydepth);
+        SurfaceMaterial material;
+        material.base = colorToHSL(Color(0.7, 0.7, 0.7));
+        material.hardness = 0.25;
+        material.reflection = 0.3;
+        material.shininess = 0.8;
+        materialValidate(&material);
+
+        col = parent->applyLightingToSurface(parent, segments[i].start, parent->getAtmosphereRenderer()->getSunDirection(), &material);
+
+        col.a = (segments[i].length >= transparency_depth) ? 1.0 : (segments[i].length / transparency_depth);
         colorMask(&result, &col);
     }
-    if (inside_length >= layer->transparencydepth)
+    if (inside_length >= transparency_depth)
     {
         result.a = 1.0;
     }
@@ -267,7 +188,7 @@ Color CloudBasicLayerRenderer::getColor(CloudLayerDefinition* layer, const Vecto
     return result;
 }
 
-bool CloudBasicLayerRenderer::alterLight(CloudLayerDefinition* layer, LightDefinition* light, const Vector3 &, const Vector3 &location)
+bool CloudBasicLayerRenderer::alterLight(BaseCloudsModel *model, LightDefinition* light, const Vector3 &, const Vector3 &location)
 {
     Vector3 start, end;
     double inside_depth, total_depth, factor;
@@ -275,27 +196,29 @@ bool CloudBasicLayerRenderer::alterLight(CloudLayerDefinition* layer, LightDefin
 
     start = location;
     end = location.add(light->direction.scale(10000.0));
-    if (not optimizeSearchLimits(layer, &start, &end))
+    if (not optimizeSearchLimits(model, &start, &end))
     {
         return false;
     }
 
-    _findSegments(layer, parent, start, light->direction, 0.1, 20, layer->lighttraversal, end.sub(start).getNorm(), &inside_depth, &total_depth, segments);
+    double light_traversal = model->getLayer()->scaling * 8.0;
+    _findSegments(model, parent, start, light->direction, 0.1, 20, light_traversal, end.sub(start).getNorm(), &inside_depth, &total_depth, segments);
 
-    if (layer->lighttraversal < 0.0001)
+    if (light_traversal < 0.0001)
     {
         factor = 0.0;
     }
     else
     {
-        factor = inside_depth / layer->lighttraversal;
+        factor = inside_depth / light_traversal;
         if (factor > 1.0)
         {
             factor = 1.0;
         }
     }
 
-    factor = 1.0 - (1.0 - layer->minimumlight) * factor;
+    double miminum_light = 0.4;
+    factor = 1.0 - (1.0 - miminum_light) * factor;
 
     light->color.r *= factor;
     light->color.g *= factor;
diff --git a/src/render/software/CloudBasicLayerRenderer.h b/src/render/software/CloudBasicLayerRenderer.h
index ad840ae..4236191 100644
--- a/src/render/software/CloudBasicLayerRenderer.h
+++ b/src/render/software/CloudBasicLayerRenderer.h
@@ -10,14 +10,19 @@
 namespace paysages {
 namespace software {
 
+/*!
+ * \brief Basic cloud layer renderer.
+ *
+ * This renderer simply iters through the cloud layer, collecting cloud segments.
+ * It does not account for local density variations.
+ */
 class SOFTWARESHARED_EXPORT CloudBasicLayerRenderer: public BaseCloudLayerRenderer
 {
 public:
     CloudBasicLayerRenderer(SoftwareRenderer* parent);
 
-    virtual double getDensity(CloudLayerDefinition* layer, const Vector3 &location) override;
-    virtual Color getColor(CloudLayerDefinition* layer, const Vector3 &eye, const Vector3 &location) override;
-    virtual bool alterLight(CloudLayerDefinition* layer, LightDefinition* light, const Vector3 &eye, const Vector3 &location) override;
+    virtual Color getColor(BaseCloudsModel *model, const Vector3 &eye, const Vector3 &location) override;
+    virtual bool alterLight(BaseCloudsModel *model, LightDefinition* light, const Vector3 &eye, const Vector3 &location) override;
 };
 
 }
diff --git a/src/render/software/CloudsRenderer.cpp b/src/render/software/CloudsRenderer.cpp
index 4f5fb99..04273d1 100644
--- a/src/render/software/CloudsRenderer.cpp
+++ b/src/render/software/CloudsRenderer.cpp
@@ -3,13 +3,20 @@
 #include "SoftwareRenderer.h"
 #include "Scenery.h"
 #include "CloudsDefinition.h"
+#include "CloudLayerDefinition.h"
 #include "BaseCloudLayerRenderer.h"
 #include "CloudBasicLayerRenderer.h"
 
+#include "clouds/BaseCloudsModel.h"
+#include "clouds/CloudModelStratoCumulus.h"
+
 CloudsRenderer::CloudsRenderer(SoftwareRenderer* parent):
     parent(parent)
 {
     fake_renderer = new BaseCloudLayerRenderer(parent);
+
+    CloudLayerDefinition* fake_layer = new CloudLayerDefinition(NULL);
+    fake_model = new BaseCloudsModel(fake_layer);
 }
 
 CloudsRenderer::~CloudsRenderer()
@@ -19,6 +26,13 @@ CloudsRenderer::~CloudsRenderer()
         delete renderer;
     }
     delete fake_renderer;
+
+    for (auto model : layer_models)
+    {
+        delete model;
+    }
+    delete fake_model->getLayer();
+    delete fake_model;
 }
 
 void CloudsRenderer::update()
@@ -29,11 +43,42 @@ void CloudsRenderer::update()
     }
     layer_renderers.clear();
 
+    for (auto model : layer_models)
+    {
+        delete model;
+    }
+    layer_models.clear();
+
     CloudsDefinition* clouds = parent->getScenery()->getClouds();
     int n = clouds->count();
     for (int i = 0; i < n; i++)
     {
         layer_renderers.push_back(new CloudBasicLayerRenderer(parent));
+
+        CloudLayerDefinition* layer = clouds->getCloudLayer(i);
+        BaseCloudsModel* model;
+        switch (layer->type)
+        {
+        case CloudLayerDefinition::STRATUS:
+        case CloudLayerDefinition::NIMBOSTRATUS:
+        case CloudLayerDefinition::CUMULUS:
+            model = new BaseCloudsModel(layer);
+            break;
+        case CloudLayerDefinition::STRATOCUMULUS:
+            model = new CloudModelStratoCumulus(layer);
+            break;
+        case CloudLayerDefinition::ALTOCUMULUS:
+        case CloudLayerDefinition::ALTOSTRATUS:
+        case CloudLayerDefinition::CUMULONIMBUS:
+        case CloudLayerDefinition::CIRROCUMULUS:
+        case CloudLayerDefinition::CIRROSTRATUS:
+        case CloudLayerDefinition::CIRRUS:
+            model = new BaseCloudsModel(layer);
+            break;
+        }
+
+        layer_models.push_back(model);
+        model->update();
     }
 }
 
@@ -49,6 +94,18 @@ BaseCloudLayerRenderer* CloudsRenderer::getLayerRenderer(unsigned int layer)
     }
 }
 
+BaseCloudsModel* CloudsRenderer::getLayerModel(unsigned int layer)
+{
+    if (layer < layer_models.size())
+    {
+        return layer_models[layer];
+    }
+    else
+    {
+        return fake_model;
+    }
+}
+
 Color CloudsRenderer::getColor(const Vector3 &eye, const Vector3 &location, const Color &base)
 {
     CloudsDefinition* definition = parent->getScenery()->getClouds();
@@ -64,10 +121,10 @@ Color CloudsRenderer::getColor(const Vector3 &eye, const Vector3 &location, cons
 
     for (int i = 0; i < n; i++)
     {
-        CloudLayerDefinition* layer = definition->getCloudLayer(i);
         BaseCloudLayerRenderer* layer_renderer = getLayerRenderer(i);
+        BaseCloudsModel* layer_model = getLayerModel(i);
 
-        Color layer_color = layer_renderer->getColor(layer, eye, location);
+        Color layer_color = layer_renderer->getColor(layer_model, eye, location);
 
         colorMask(&cumul, &layer_color);
     }
diff --git a/src/render/software/CloudsRenderer.h b/src/render/software/CloudsRenderer.h
index f938660..891e3dd 100644
--- a/src/render/software/CloudsRenderer.h
+++ b/src/render/software/CloudsRenderer.h
@@ -18,32 +18,45 @@ public:
     virtual ~CloudsRenderer();
 
     /*!
-     * Update the renderer with the bound scenery.
+     * \brief Update the renderer with the bound scenery.
+     *
+     * Don't call this if another thread is currently using this renderer.
      */
     void update();
 
     /*!
-     * Get the layer renderer for a given layer.
+     * \brief Get the layer renderer for a given layer.
      *
      * The returned renderer is managed by this object and should not be deleted.
      */
     virtual BaseCloudLayerRenderer* getLayerRenderer(unsigned int layer);
 
     /*!
-     * Get the composited color, as applied on a base color and location.
+     * \brief Get the cloud model for a given layer.
+     *
+     * The returned model is managed by this object and should not be deleted.
+     */
+    virtual BaseCloudsModel* getLayerModel(unsigned int layer);
+
+    /*!
+     * \brief Get the composited color, as applied on a base color and location.
      */
     virtual Color getColor(const Vector3 &eye, const Vector3 &location, const Color &base);
 
     /*!
-     * Alter a light, as if passed through all layers.
+     * \brief Alter a light, as if passed through all layers.
      *
      * Return true if the light was altered.
      */
     virtual bool alterLight(LightDefinition* light, const Vector3 &eye, const Vector3 &location);
 private:
     SoftwareRenderer* parent;
+
     std::vector<BaseCloudLayerRenderer*> layer_renderers;
     BaseCloudLayerRenderer* fake_renderer;
+
+    std::vector<BaseCloudsModel*> layer_models;
+    BaseCloudsModel* fake_model;
 };
 
 }
diff --git a/src/render/software/clouds/BaseCloudsModel.cpp b/src/render/software/clouds/BaseCloudsModel.cpp
new file mode 100644
index 0000000..7e943e5
--- /dev/null
+++ b/src/render/software/clouds/BaseCloudsModel.cpp
@@ -0,0 +1,49 @@
+#include "BaseCloudsModel.h"
+
+#include "CloudLayerDefinition.h"
+
+BaseCloudsModel::BaseCloudsModel(CloudLayerDefinition *layer):
+    layer(layer)
+{
+}
+
+BaseCloudsModel::~BaseCloudsModel()
+{
+}
+
+void BaseCloudsModel::update()
+{
+}
+
+void BaseCloudsModel::getAltitudeRange(double *min_altitude, double *max_altitude) const
+{
+    *min_altitude = layer->altitude;
+    *max_altitude = layer->altitude * layer->scaling;
+}
+
+void BaseCloudsModel::getDetailRange(double *min_step, double *max_step) const
+{
+    *min_step = 0.1;
+    *max_step = 1.0;
+}
+
+double BaseCloudsModel::getProbability(const Vector3 &, double) const
+{
+    return 1.0;
+}
+
+double BaseCloudsModel::getDensity(const Vector3 &) const
+{
+    return 0.0;
+}
+
+Color BaseCloudsModel::filterLight(const Color &light, double, double) const
+{
+    return light;
+}
+
+Color BaseCloudsModel::applyLightExit(const Color &light, const Vector3 &, const Vector3 &) const
+{
+    return light;
+}
+
diff --git a/src/render/software/clouds/BaseCloudsModel.h b/src/render/software/clouds/BaseCloudsModel.h
new file mode 100644
index 0000000..594ae04
--- /dev/null
+++ b/src/render/software/clouds/BaseCloudsModel.h
@@ -0,0 +1,38 @@
+#ifndef BASECLOUDSMODEL_H
+#define BASECLOUDSMODEL_H
+
+#include "../software_global.h"
+
+#include "Color.h"
+
+namespace paysages {
+namespace software {
+
+/*!
+ * \brief Abstract class for all cloud models (cirrus, cumulus...).
+ */
+class BaseCloudsModel
+{
+public:
+    BaseCloudsModel(CloudLayerDefinition *layer);
+    virtual ~BaseCloudsModel();
+
+    virtual void update();
+
+    virtual void getAltitudeRange(double *min_altitude, double *max_altitude) const;
+    virtual void getDetailRange(double *min_step, double *max_step) const;
+    virtual double getProbability(const Vector3 &location, double radius) const;
+    virtual double getDensity(const Vector3 &location) const;
+    virtual Color filterLight(const Color &light, double length, double density) const;
+    virtual Color applyLightExit(const Color &light, const Vector3 &light_direction, const Vector3 &direction_to_eye) const;
+
+    inline CloudLayerDefinition* getLayer() const {return layer;}
+
+protected:
+    CloudLayerDefinition *layer;
+};
+
+}
+}
+
+#endif // BASECLOUDSMODEL_H
diff --git a/src/render/software/clouds/CloudModelStratoCumulus.cpp b/src/render/software/clouds/CloudModelStratoCumulus.cpp
new file mode 100644
index 0000000..ca5fd57
--- /dev/null
+++ b/src/render/software/clouds/CloudModelStratoCumulus.cpp
@@ -0,0 +1,67 @@
+#include "CloudModelStratoCumulus.h"
+
+#include "NoiseGenerator.h"
+#include "Vector3.h"
+#include "CloudLayerDefinition.h"
+
+CloudModelStratoCumulus::CloudModelStratoCumulus(CloudLayerDefinition* layer):
+    BaseCloudsModel(layer)
+{
+    noise = new NoiseGenerator();
+}
+
+CloudModelStratoCumulus::~CloudModelStratoCumulus()
+{
+    delete noise;
+}
+
+void CloudModelStratoCumulus::update()
+{
+    noise->clearLevels();
+    noise->addLevelSimple(1.0, -1.0, 1.0);
+    noise->addLevelSimple(1.0 / 2.0, -0.6, 0.6);
+    noise->addLevelSimple(1.0 / 4.0, -0.3, 0.3);
+    noise->addLevelSimple(1.0 / 10.0, -0.15, 0.15);
+    noise->addLevelSimple(1.0 / 20.0, -0.09, 0.09);
+    noise->addLevelSimple(1.0 / 40.0, -0.06, 0.06);
+    noise->addLevelSimple(1.0 / 60.0, -0.03, 0.03);
+    noise->addLevelSimple(1.0 / 80.0, -0.015, 0.015);
+    noise->addLevelSimple(1.0 / 100.0, -0.06, 0.06);
+    noise->addLevelSimple(1.0 / 150.0, -0.015, 0.015);
+    noise->addLevelSimple(1.0 / 200.0, -0.009, 0.009);
+    noise->addLevelSimple(1.0 / 400.0, -0.024, 0.024);
+    noise->addLevelSimple(1.0 / 800.0, -0.003, 0.003);
+    noise->addLevelSimple(1.0 / 1000.0, -0.0015, 0.0015);
+    noise->normalizeAmplitude(-3.0, 3.0, 0);
+}
+
+void CloudModelStratoCumulus::getAltitudeRange(double *min_altitude, double *max_altitude) const
+{
+    *min_altitude = 2.0 + 7.0 * layer->altitude;
+    *max_altitude = *min_altitude + 5.0 * layer->scaling;
+}
+
+double CloudModelStratoCumulus::getDensity(const Vector3 &location) const
+{
+    double val;
+    double min_altitude, max_altitude;
+
+    getAltitudeRange(&min_altitude, &max_altitude);
+
+    if (location.y < min_altitude || location.y > max_altitude)
+    {
+        return 0.0;
+    }
+    else
+    {
+        double x = location.x / (5.0 * layer->scaling);
+        double y = (location.y - min_altitude) / (5.0 * layer->scaling);
+        double z = location.z / (5.0 * layer->scaling);
+
+        //double coverage = layer->coverage * layer->_coverage_by_altitude->getValue((position.y - layer->altitude) / layer->scaling);
+        double coverage = layer->coverage;
+
+        val = 0.5 * noise->get3DTotal(x, y, z);
+        return val - 0.5 + coverage;
+    }
+}
diff --git a/src/render/software/clouds/CloudModelStratoCumulus.h b/src/render/software/clouds/CloudModelStratoCumulus.h
new file mode 100644
index 0000000..9bb039b
--- /dev/null
+++ b/src/render/software/clouds/CloudModelStratoCumulus.h
@@ -0,0 +1,29 @@
+#ifndef CLOUDMODELSTRATOCUMULUS_H
+#define CLOUDMODELSTRATOCUMULUS_H
+
+#include "../software_global.h"
+
+#include "BaseCloudsModel.h"
+
+namespace paysages {
+namespace software {
+
+class CloudModelStratoCumulus : public BaseCloudsModel
+{
+public:
+    CloudModelStratoCumulus(CloudLayerDefinition* layer);
+    virtual ~CloudModelStratoCumulus();
+
+    virtual void update() override;
+
+    virtual void getAltitudeRange(double *min_altitude, double *max_altitude) const override;
+    virtual double getDensity(const Vector3 &location) const override;
+
+private:
+    NoiseGenerator* noise;
+};
+
+}
+}
+
+#endif // CLOUDMODELSTRATOCUMULUS_H
diff --git a/src/render/software/software.pro b/src/render/software/software.pro
index 88ed67a..855fea7 100644
--- a/src/render/software/software.pro
+++ b/src/render/software/software.pro
@@ -20,7 +20,9 @@ SOURCES += SoftwareRenderer.cpp \
     CloudsRenderer.cpp \
     BaseCloudLayerRenderer.cpp \
     SkyRasterizer.cpp \
-    CloudBasicLayerRenderer.cpp
+    CloudBasicLayerRenderer.cpp \
+    clouds/BaseCloudsModel.cpp \
+    clouds/CloudModelStratoCumulus.cpp
 
 HEADERS += SoftwareRenderer.h\
         software_global.h \
@@ -30,7 +32,9 @@ HEADERS += SoftwareRenderer.h\
     CloudsRenderer.h \
     BaseCloudLayerRenderer.h \
     SkyRasterizer.h \
-    CloudBasicLayerRenderer.h
+    CloudBasicLayerRenderer.h \
+    clouds/BaseCloudsModel.h \
+    clouds/CloudModelStratoCumulus.h
 
 unix:!symbian {
     maemo5 {
diff --git a/src/render/software/software_global.h b/src/render/software/software_global.h
index 1cb06aa..e361f99 100644
--- a/src/render/software/software_global.h
+++ b/src/render/software/software_global.h
@@ -24,6 +24,7 @@ namespace software {
 
     class CloudsRenderer;
     class BaseCloudLayerRenderer;
+    class BaseCloudsModel;
 }
 }