diff --git a/TODO b/TODO
index 4055377..ff2a26b 100644
--- a/TODO
+++ b/TODO
@@ -1,8 +1,7 @@
-- Restore render progress
-- Clouds are lighted without filtering from ground (clouds lighted at night !)
 - Camera should respect ratio aspect of render area.
 - All noises should use the same entropy pool (saved separately), and avoid reallocs.
 - Implement light multi-sampling (mainly for skydome).
 - Implement scaling and scrolling on previews.
 - Water and terrain LOD moves with the camera, fix it like in the wanderer.
-- Find the random segfault at start (in PreviewTerrainColor::getColor).
\ No newline at end of file
+- Find the random segfault at start (in PreviewTerrainColor::getColor).
+- Restore render progress.
diff --git a/lib_paysages/system.c b/lib_paysages/system.c
index 38b4de3..c2d64ec 100644
--- a/lib_paysages/system.c
+++ b/lib_paysages/system.c
@@ -31,6 +31,9 @@ static int _getCoreCount()
 #endif
 #ifdef _SC_NPROCESSORS_ONLN
     core_count = (int)sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+#ifdef DEBUG_ONETHREAD
+    core_count = 1;
 #endif
     return core_count;
 }
diff --git a/lib_paysages/terrain.c b/lib_paysages/terrain.c
index c54aac8..9290ae7 100644
--- a/lib_paysages/terrain.c
+++ b/lib_paysages/terrain.c
@@ -174,6 +174,16 @@ Color terrainLightFilter(TerrainDefinition* definition, Renderer* renderer, Colo
     {
         return light;
     }
+    else if (direction_to_light.y < 0.05)
+    {
+        return COLOR_BLACK;
+    }
+    else if (direction_to_light.y < 0.0000)
+    {
+        light.r *= (0.05 + direction_to_light.y) / 0.05;
+        light.g *= (0.05 + direction_to_light.y) / 0.05;
+        light.b *= (0.05 + direction_to_light.y) / 0.05;
+    }
 
     inc_factor = (double)renderer->render_quality;
     inc_base = 1.0;
@@ -228,6 +238,7 @@ static Color _getColor(TerrainDefinition* definition, Renderer* renderer, Vector
 
     color = renderer->applyTextures(renderer, point, precision);
     color = renderer->applyAtmosphere(renderer, point, color);
+    color = renderer->applyClouds(renderer, color, renderer->camera_location, point);
 
     return color;
 }
diff --git a/lib_paysages/water.c b/lib_paysages/water.c
index 6fb5005..6b77600 100644
--- a/lib_paysages/water.c
+++ b/lib_paysages/water.c
@@ -219,6 +219,7 @@ WaterResult waterGetColorDetail(WaterDefinition* definition, Renderer* renderer,
     material.base = color;
     color = renderer->applyLightingToSurface(renderer, location, normal, material);
     color = renderer->applyAtmosphere(renderer, location, color);
+    color = renderer->applyClouds(renderer, color, renderer->camera_location, location);
 
     result.base = definition->material.base;
     result.final = color;