diff --git a/ChangeLog b/ChangeLog
index 5d20049..27d4fc1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,7 @@
 Global :
   * Version handling in saved files.
   * Replaced old noise algorithm with Simplex Noise (up to 4 times faster).
+  * New noise settings for better shape control.
 
 Terrain :
   * Added canvases to paint the shape directly.
@@ -16,9 +17,11 @@ Textures :
 Water :
   * Added foam.
 
-Sky :
+Atmosphere :
+  * Merged with sky module.
   * New sky model (based on Preetham's work).
   * Added sun halo control.
+  * Better previews.
 
 Clouds :
   * Added clouds hardness to light.
diff --git a/gui_qt/formatmosphere.cpp b/gui_qt/formatmosphere.cpp
index 926f3d4..709c9b5 100644
--- a/gui_qt/formatmosphere.cpp
+++ b/gui_qt/formatmosphere.cpp
@@ -26,21 +26,7 @@ public:
 protected:
     QColor getColor(double x, double y)
     {
-        y -= 100.0 * scaling;
-        if (y > 0.0)
-        {
-            return QColor(0, 0, 0);
-        }
-        else
-        {
-            Vector3 look;
-
-            look.x = 1.0;
-            look.y = -y;
-            look.z = x;
-
-            return colorToQColor(_renderer.atmosphere->getSkyColor(&_renderer, look));
-        }
+        return colorToQColor(atmosphereGetPreview(&_renderer, x, -y, M_PI_2));
     }
     void updateData()
     {
@@ -63,21 +49,7 @@ public:
 protected:
     QColor getColor(double x, double y)
     {
-        y -= 100.0 * scaling;
-        if (y > 0.0)
-        {
-            return QColor(0, 0, 0);
-        }
-        else
-        {
-            Vector3 look;
-
-            look.x = -1.0;
-            look.y = -y;
-            look.z = -x;
-
-            return colorToQColor(_renderer.atmosphere->getSkyColor(&_renderer, look));
-        }
+        return colorToQColor(atmosphereGetPreview(&_renderer, x, -y, -M_PI_2));
     }
     void updateData()
     {
@@ -91,8 +63,6 @@ private:
 FormAtmosphere::FormAtmosphere(QWidget *parent):
     BaseForm(parent)
 {
-    BaseInput* input;
-
     _definition = (AtmosphereDefinition*)AtmosphereDefinitionClass.create();
 
     previewWest = new PreviewSkyWest(this);
diff --git a/lib_paysages/atmosphere/preview.c b/lib_paysages/atmosphere/preview.c
new file mode 100644
index 0000000..5cd3fbc
--- /dev/null
+++ b/lib_paysages/atmosphere/preview.c
@@ -0,0 +1,151 @@
+#include "public.h"
+
+#include "../renderer.h"
+#include "../lighting.h"
+
+/*
+ * Atmosphere previews.
+ */
+
+typedef struct
+{
+    Vector3 location;
+    double size;
+} Mount;
+
+#define MOUNTS_COUNT 11
+static Mount MOUNTS[MOUNTS_COUNT] = {
+    {{2.0, 0.0, -4.0}, 4.0},
+    {{-1.0, 0.0, -6.0}, 4.0},
+    {{3.0, 0.0, -10.0}, 6.0},
+    {{-8.0, 0.0, -15.0}, 6.0},
+    {{10.0, 0.0, -20.0}, 6.0},
+    {{-6.0, 0.0, -30.0}, 8.0},
+    {{15.0, 0.0, -40.0}, 8.0},
+    {{-20.0, 0.0, -50.0}, 8.0},
+    {{10.0, 0.0, -60.0}, 10.0},
+    {{-5.0, 0.0, -80.0}, 10.0},
+    {{30.0, 0.0, -100.0}, 10.0},
+};
+
+static SurfaceMaterial MOUNT_MATERIAL = {{0.0, 0.0, 0.0, 1.0}, 0.0, 0.0};
+
+static inline int _rayIntersectsTriangle(Vector3 p, Vector3 d, Vector3 v0, Vector3 v1, Vector3 v2, Vector3* hit)
+{
+    Vector3 e1, e2, h, s, q;
+    double a, f, u, v, t;
+
+    e1 = v3Sub(v1, v0);
+    e2 = v3Sub(v2, v0);
+
+    h = v3Cross(d, e2);
+    a = v3Dot(e1, h);
+
+    if (a > -0.00001 && a < 0.00001)
+    {
+        return 0;
+    }
+
+    f = 1.0 / a;
+    s = v3Sub(p, v0);
+    u = f * v3Dot(s, h);
+
+    if (u < 0.0 || u > 1.0)
+    {
+        return 0;
+    }
+
+    q = v3Cross(s, e1);
+    v = f * v3Dot(d, q);
+
+    if (v < 0.0 || u + v > 1.0)
+    {
+        return 0;
+    }
+
+    t = f * v3Dot(e2, q);
+
+    if (t > 0.00001)
+    {
+        *hit = v3Add(p, v3Scale(d, t));
+        return 1;
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+static inline int _checkHitMountain(Vector3 eye, Vector3 direction, Mount mount, Vector3* hit)
+{
+    Vector3 v0 = mount.location;
+    Vector3 v1 = mount.location;
+    Vector3 v2 = mount.location;
+    v0.x -= mount.size;
+    v1.x += mount.size;
+    v2.y += mount.size;
+    return _rayIntersectsTriangle(eye, direction, v0, v1, v2, hit);
+}
+
+static inline int _checkHitGround(Vector3 eye, Vector3 direction, Vector3* hit)
+{
+    if (direction.y > -0.0001)
+    {
+        return 0;
+    }
+    else
+    {
+        hit->x = eye.x - direction.x * eye.y / direction.y;
+        hit->y = 0.0;
+        hit->z = eye.z - direction.z * eye.y / direction.y;
+        return 1;
+    }
+}
+
+static inline int _checkHit(Vector3 eye, Vector3 direction, Vector3* hit, Vector3* normal)
+{
+    int i;
+    for (i = 0; i < MOUNTS_COUNT; i++)
+    {
+        if (_checkHitMountain(eye, direction, MOUNTS[i], hit))
+        {
+            *normal = VECTOR_SOUTH;
+            return 1;
+        }
+    }
+
+    *normal = VECTOR_UP;
+    return _checkHitGround(eye, direction, hit);
+}
+
+Color atmosphereGetPreview(Renderer* renderer, double x, double y, double heading)
+{
+    Vector3 eye = {0.0, 8.0, 0.0};
+    Vector3 direction = {x, y, -1.0};
+    Vector3 hit, normal;
+    Matrix4 rotation;
+
+    rotation = m4NewRotateY(heading);
+
+    if (_checkHit(eye, direction, &hit, &normal))
+    {
+        Color color;
+        LightStatus light;
+
+        normal = m4Transform(rotation, normal);
+        hit = m4Transform(rotation, hit);
+
+        /* TODO Refactor lighting module for this to work */
+        renderer->getLightStatus(renderer, &light, hit);
+        color = renderer->applyLightStatus(renderer, &light, hit, normal, MOUNT_MATERIAL);
+        color = COLOR_BLACK;
+
+        return renderer->atmosphere->applyAerialPerspective(renderer, hit, color);
+    }
+    else
+    {
+        direction = m4Transform(rotation, direction);
+
+        return renderer->atmosphere->getSkyColor(renderer, direction);
+    }
+}
diff --git a/lib_paysages/atmosphere/public.h b/lib_paysages/atmosphere/public.h
index 294fb48..623c213 100644
--- a/lib_paysages/atmosphere/public.h
+++ b/lib_paysages/atmosphere/public.h
@@ -75,6 +75,7 @@ extern StandardDefinition AtmosphereDefinitionClass;
 extern StandardRenderer AtmosphereRendererClass;
 
 void atmosphereRenderSkydome(Renderer* renderer);
+Color atmosphereGetPreview(Renderer* renderer, double x, double y, double heading);
 
 #ifdef __cplusplus
 }