diff --git a/gui_qt/dialogheightmap.cpp b/gui_qt/dialogheightmap.cpp
index e69ee7a..b16f90f 100644
--- a/gui_qt/dialogheightmap.cpp
+++ b/gui_qt/dialogheightmap.cpp
@@ -68,7 +68,7 @@ DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap) : Dialog
     
     combobox = new QComboBox(panel);
     combobox->addItem(tr("Raise / lower"));
-    combobox->addItem(tr("Smooth / add noise"));
+    combobox->addItem(tr("Add noise / smooth"));
     connect(combobox, SIGNAL(currentIndexChanged(int)), this, SLOT(brushModeChanged(int)));
     panel->layout()->addWidget(combobox);
     
@@ -76,10 +76,10 @@ DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap) : Dialog
     panel->layout()->addWidget(label);
     
     slider = new QSlider(Qt::Horizontal, panel);
-    slider->setRange(6, 150);
+    slider->setRange(6, 300);
     connect(slider, SIGNAL(valueChanged(int)), this, SLOT(brushSizeChanged(int)));
     panel->layout()->addWidget(slider);
-    slider->setValue(30);
+    slider->setValue(60);
 
     label = new QLabel(tr("Brush smoothing"), panel);
     panel->layout()->addWidget(label);
diff --git a/gui_qt/widgetheightmap.cpp b/gui_qt/widgetheightmap.cpp
index 5fac744..50fee3e 100644
--- a/gui_qt/widgetheightmap.cpp
+++ b/gui_qt/widgetheightmap.cpp
@@ -176,13 +176,14 @@ void WidgetHeightMap::timerEvent(QTimerEvent*)
         brush.relative_z = (_brush_z + 40.0) / 80.0;
         brush.hard_radius = _brush_size * (1.0 - _brush_smoothing) / 80.0;
         brush.smoothed_size = _brush_size * _brush_smoothing / 80.0;
+        brush.total_radius = brush.hard_radius + brush.smoothed_size;
         
         brush_strength = _brush_strength * duration / 0.1;
         
         switch (_brush_mode)
         {
             case HEIGHTMAP_BRUSH_RAISE:
-                heightmapBrushElevation(_heightmap, &brush, brush_strength * _last_brush_action);
+                heightmapBrushElevation(_heightmap, &brush, brush_strength * _last_brush_action * 20.0);
                 break;
             case HEIGHTMAP_BRUSH_SMOOTH:
                 if (_last_brush_action < 0)
@@ -191,7 +192,7 @@ void WidgetHeightMap::timerEvent(QTimerEvent*)
                 }
                 else
                 {
-                    heightmapBrushAddNoise(_heightmap, &brush, _brush_noise, brush_strength);
+                    heightmapBrushAddNoise(_heightmap, &brush, _brush_noise, brush_strength * 10.0);
                 }
                 break;
             default:
diff --git a/lib_paysages/heightmap.c b/lib_paysages/heightmap.c
index 93ff6ec..47b0767 100644
--- a/lib_paysages/heightmap.c
+++ b/lib_paysages/heightmap.c
@@ -170,45 +170,12 @@ static inline void _getBrushBoundaries(HeightMapBrush* brush, int rx, int rz, in
     }
 }
 
-void heightmapBrushElevation(HeightMap* heightmap, HeightMapBrush* brush, double value)
+typedef double (*BrushCallback)(HeightMap* heightmap, HeightMapBrush* brush, double x, double z, double basevalue, double influence, double force, void* data);
+
+static inline void _applyBrush(HeightMap* heightmap, HeightMapBrush* brush, double force, void* data, BrushCallback callback)
 {
     int x, x1, x2, z, z1, z2;
-    double dx, dz, distance;
-    
-    _getBrushBoundaries(brush, heightmap->resolution_x - 1, heightmap->resolution_z - 1, &x1, &x2, &z1, &z2);
-    
-    for (x = x1; x <= x2; x++)
-    {
-        dx = (double)x / (double)heightmap->resolution_x;
-        for (z = z1; z <= z2; z++)
-        {
-            dz = (double)z / (double)heightmap->resolution_z;
-            distance = sqrt((brush->relative_x - dx) * (brush->relative_x - dx) + (brush->relative_z - dz) * (brush->relative_z - dz));
-            
-            if (distance > brush->hard_radius)
-            {
-                if (distance <= brush->hard_radius + brush->smoothed_size)
-                {
-                    heightmap->data[z * heightmap->resolution_x + x] += value * (1.0 - (distance - brush->hard_radius) / brush->smoothed_size);
-                }
-            }
-            else
-            {
-                heightmap->data[z * heightmap->resolution_x + x] += value;
-            }
-        }
-    }
-}
-
-void heightmapBrushSmooth(HeightMap* heightmap, HeightMapBrush* brush, double value)
-{
-    /* TODO */
-}
-
-void heightmapBrushAddNoise(HeightMap* heightmap, HeightMapBrush* brush, NoiseGenerator* generator, double value)
-{
-    int x, x1, x2, z, z1, z2;
-    double dx, dz, distance, factor, brush_size;
+    double dx, dz, distance, influence, brush_size;
     
     _getBrushBoundaries(brush, heightmap->resolution_x - 1, heightmap->resolution_z - 1, &x1, &x2, &z1, &z2);
     brush_size = brush->hard_radius + brush->smoothed_size;
@@ -225,7 +192,7 @@ void heightmapBrushAddNoise(HeightMap* heightmap, HeightMapBrush* brush, NoiseGe
             {
                 if (distance <= brush->hard_radius + brush->smoothed_size)
                 {
-                    factor = (1.0 - (distance - brush->hard_radius) / brush->smoothed_size);
+                    influence = (1.0 - (distance - brush->hard_radius) / brush->smoothed_size);
                 }
                 else
                 {
@@ -234,10 +201,51 @@ void heightmapBrushAddNoise(HeightMap* heightmap, HeightMapBrush* brush, NoiseGe
             }
             else
             {
-                factor = 1.0;
+                influence = 1.0;
             }
             
-            heightmap->data[z * heightmap->resolution_x + x] += factor * noiseGet2DTotal(generator, dx / brush_size, dz / brush_size) * brush_size;
+            heightmap->data[z * heightmap->resolution_x + x] = callback(heightmap, brush, dx, dz, heightmap->data[z * heightmap->resolution_x + x], influence, force, data);
         }
     }
 }
+
+static double _applyBrushElevation(HeightMap* heightmap, HeightMapBrush* brush, double x, double z, double basevalue, double influence, double force, void* data)
+{
+    return basevalue + influence * force * brush->total_radius;
+}
+
+void heightmapBrushElevation(HeightMap* heightmap, HeightMapBrush* brush, double value)
+{
+    _applyBrush(heightmap, brush, value, NULL, _applyBrushElevation);
+}
+
+static double _applyBrushSmooth(HeightMap* heightmap, HeightMapBrush* brush, double x, double z, double basevalue, double influence, double force, void* data)
+{
+    double ideal, factor;
+    ideal = heightmapGetValue(heightmap, x + brush->total_radius * 0.5, z);
+    ideal += heightmapGetValue(heightmap, x - brush->total_radius * 0.5, z);
+    ideal += heightmapGetValue(heightmap, x, z - brush->total_radius * 0.5);
+    ideal += heightmapGetValue(heightmap, x, z + brush->total_radius * 0.5);
+    ideal /= 4.0;
+    factor = influence * force;
+    if (factor > 1.0)
+    {
+        factor = 0.0;
+    }
+    return basevalue + (ideal - basevalue) * factor;
+}
+
+void heightmapBrushSmooth(HeightMap* heightmap, HeightMapBrush* brush, double value)
+{
+    _applyBrush(heightmap, brush, value, NULL, _applyBrushSmooth);
+}
+
+static double _applyBrushAddNoise(HeightMap* heightmap, HeightMapBrush* brush, double x, double z, double basevalue, double influence, double force, void* data)
+{
+    return basevalue + noiseGet2DTotal((NoiseGenerator*)data, x / brush->total_radius, z / brush->total_radius) * influence * force * brush->total_radius;
+}
+
+void heightmapBrushAddNoise(HeightMap* heightmap, HeightMapBrush* brush, NoiseGenerator* generator, double value)
+{
+    _applyBrush(heightmap, brush, value, generator, _applyBrushAddNoise);
+}
diff --git a/lib_paysages/heightmap.h b/lib_paysages/heightmap.h
index 53e7d7d..23e070a 100644
--- a/lib_paysages/heightmap.h
+++ b/lib_paysages/heightmap.h
@@ -23,6 +23,7 @@ typedef struct
     double relative_z;
     double hard_radius;
     double smoothed_size;
+    double total_radius;
 } HeightMapBrush;
 
 HeightMap heightmapCreate();