diff --git a/src/rendering/terrain/ter_painting.c b/src/rendering/terrain/ter_painting.c
index fd90ddf..1adc5ea 100644
--- a/src/rendering/terrain/ter_painting.c
+++ b/src/rendering/terrain/ter_painting.c
@@ -571,7 +571,7 @@ static double _applyBrushReset(TerrainHeightMap* heightmap, TerrainBrush* brush,
     UNUSED(brush);
     UNUSED(data);
 
-    double ideal = terrainGetInterpolatedHeight(heightmap->terrain, x, z, 0, 0);
+    double ideal = terrainGetInterpolatedHeight(heightmap->terrain, x * heightmap->terrain->scaling, z * heightmap->terrain->scaling, 0, 0);
     return basevalue + (ideal - basevalue) * influence * force;
 }
 
diff --git a/src/testing/test_terrain_painting.c b/src/testing/test_terrain_painting.c
index 4366baa..8fd2f20 100644
--- a/src/testing/test_terrain_painting.c
+++ b/src/testing/test_terrain_painting.c
@@ -132,65 +132,76 @@ START_TEST(test_terrain_painting_brush_smooth)
 
 END_TEST
 
-static void _checkBrushResult(TerrainDefinition* terrain, TerrainBrush* brush, double center, double midhard, double hard, double midsoft, double soft, double exter)
+static void _checkBrushResultSides(TerrainDefinition* terrain, TerrainBrush* brush, double center, double midhard, double hard, double midsoft, double soft, double exter, double neg_midhard, double neg_hard, double neg_midsoft, double neg_soft, double neg_exter)
 {
     UNUSED(brush);
-    ck_assert_double_eq(terrainGetGridHeight(terrain, -5, 0, 1), exter);
-    ck_assert_double_eq(terrainGetGridHeight(terrain, -4, 0, 1), soft);
-    ck_assert_double_eq(terrainGetGridHeight(terrain, -3, 0, 1), midsoft);
-    ck_assert_double_eq(terrainGetGridHeight(terrain, -2, 0, 1), hard);
-    ck_assert_double_eq(terrainGetGridHeight(terrain, -1, 0, 1), midhard);
+
     ck_assert_double_eq(terrainGetGridHeight(terrain, 0, 0, 1), center);
+
     ck_assert_double_eq(terrainGetGridHeight(terrain, 1, 0, 1), midhard);
     ck_assert_double_eq(terrainGetGridHeight(terrain, 2, 0, 1), hard);
     ck_assert_double_eq(terrainGetGridHeight(terrain, 3, 0, 1), midsoft);
     ck_assert_double_eq(terrainGetGridHeight(terrain, 4, 0, 1), soft);
     ck_assert_double_eq(terrainGetGridHeight(terrain, 5, 0, 1), exter);
+
+    ck_assert_double_eq(terrainGetGridHeight(terrain, -1, 0, 1), neg_midhard);
+    ck_assert_double_eq(terrainGetGridHeight(terrain, -2, 0, 1), neg_hard);
+    ck_assert_double_eq(terrainGetGridHeight(terrain, -3, 0, 1), neg_midsoft);
+    ck_assert_double_eq(terrainGetGridHeight(terrain, -4, 0, 1), neg_soft);
+    ck_assert_double_eq(terrainGetGridHeight(terrain, -5, 0, 1), neg_exter);
+}
+
+
+static void _checkBrushResult(TerrainDefinition* terrain, TerrainBrush* brush, double center, double midhard, double hard, double midsoft, double soft, double exter, int mirror)
+{
+    if (mirror)
+    {
+        _checkBrushResultSides(terrain, brush, center, midhard, hard, midsoft, soft, exter, -midhard, -hard, -midsoft, -soft, -exter);
+    }
+    else
+    {
+        _checkBrushResultSides(terrain, brush, center, midhard, hard, midsoft, soft, exter, midhard, hard, midsoft, soft, exter);
+    }
 }
 
 START_TEST(test_terrain_painting_brush_flatten)
 {
     /* Set up */
     TerrainDefinition* terrain = _setUpDefinition();
-    TerrainBrush brush;
-    brush.relative_x = 0.0;
-    brush.relative_z = 0.0;
-    brush.hard_radius = 2.0;
-    brush.smoothed_size = 2.0;
-    brush.total_radius = 4.0;
+    TerrainBrush brush = {0.0, 0.0, 2.0, 2.0, 4.0};
     terrain->height = 1.0;
     terrain->scaling = 1.0;
     noiseForceValue(terrain->_height_noise, 0.0);
 
     /* Test flattening center at 0.5 */
-    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0);
     terrainBrushFlatten(terrain->height_map, &brush, 0.5, 1.0);
-    _checkBrushResult(terrain, &brush, 0.5, 0.5, 0.5, 0.25, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.5, 0.5, 0.5, 0.25, 0.0, 0.0, 0);
 
     /* Test brush strength */
     terrainClearPainting(terrain->height_map);
-    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0);
     terrainBrushFlatten(terrain->height_map, &brush, 0.5, 0.01);
-    _checkBrushResult(terrain, &brush, 0.005, 0.005, 0.005, 0.0025, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.005, 0.005, 0.005, 0.0025, 0.0, 0.0, 0);
 
     /* Test cumulative effect */
     terrainBrushFlatten(terrain->height_map, &brush, 0.5, 0.01);
-    _checkBrushResult(terrain, &brush, 0.00995, 0.00995, 0.00995, 0.0049875, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.00995, 0.00995, 0.00995, 0.0049875, 0.0, 0.0, 0);
 
     /* Test with height modifier */
     terrain->height = 10.0;
     terrainClearPainting(terrain->height_map);
-    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0);
     terrainBrushFlatten(terrain->height_map, &brush, 0.5, 1.0);
-    _checkBrushResult(terrain, &brush, 0.05, 0.05, 0.05, 0.025, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.05, 0.05, 0.05, 0.025, 0.0, 0.0, 0);
 
     /* Test with scaling modifier */
     terrain->height = 10.0;
     terrain->scaling = 2.0;
     terrainClearPainting(terrain->height_map);
-    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0);
     terrainBrushFlatten(terrain->height_map, &brush, 0.5, 1.0);
-    _checkBrushResult(terrain, &brush, 0.05, 0.05, 0.05, 0.025, 0.0, 0.0);
+    _checkBrushResult(terrain, &brush, 0.05, 0.05, 0.05, 0.025, 0.0, 0.0, 0);
 
     /* Tear down */
     _tearDownDefinition(terrain);
@@ -202,12 +213,63 @@ START_TEST(test_terrain_painting_brush_reset)
 {
     /* Set up */
     TerrainDefinition* terrain = _setUpDefinition();
+    TerrainBrush brush = {0.0, 0.0, 2.0, 2.0, 4.0};
+    TerrainBrush brush_full = {0.0, 0.0, 4.0, 0.0, 4.0};
+    terrain->height = 1.0;
+    terrain->scaling = 1.0;
+    noiseForceValue(terrain->_height_noise, 1.0);
 
-    /* Test */
-    /* TODO */
+    /* Test resetting at center */
+    _checkBrushResult(terrain, &brush, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0);
+    terrainBrushFlatten(terrain->height_map, &brush_full, 2.0, 1.0);
+    _checkBrushResult(terrain, &brush, 2.0, 2.0, 2.0, 2.0, 2.0, 1.0, 0);
+    terrainBrushReset(terrain->height_map, &brush, 1.0);
+    _checkBrushResult(terrain, &brush, 1.0, 1.0, 1.0, 1.5, 2.0, 1.0, 0);
+
+    /* Test brush strength */
+    terrainClearPainting(terrain->height_map);
+    _checkBrushResult(terrain, &brush, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0);
+    terrainBrushFlatten(terrain->height_map, &brush_full, 2.0, 1.0);
+    _checkBrushResult(terrain, &brush, 2.0, 2.0, 2.0, 2.0, 2.0, 1.0, 0);
+    terrainBrushReset(terrain->height_map, &brush, 0.1);
+    _checkBrushResult(terrain, &brush, 1.9, 1.9, 1.9, 1.95, 2.0, 1.0, 0);
+
+    /* Test cumulative effect */
+    terrainBrushReset(terrain->height_map, &brush, 0.1);
+    _checkBrushResult(terrain, &brush, 1.81, 1.81, 1.81, 1.9025, 2.0, 1.0, 0);
+
+    /* Test with height modifier */
+    terrain->height = 10.0;
+    terrainClearPainting(terrain->height_map);
+    _checkBrushResult(terrain, &brush, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0);
+    terrainBrushFlatten(terrain->height_map, &brush_full, 2.0, 1.0);
+    _checkBrushResult(terrain, &brush, 1.1, 1.1, 1.1, 1.1, 1.1, 1.0, 0);
+    terrainBrushReset(terrain->height_map, &brush, 0.1);
+    _checkBrushResult(terrain, &brush, 1.099, 1.099, 1.099, 1.0995, 1.1, 1.0, 0);
+
+    /* Test with scaling modifier */
+    terrain->height = 10.0;
+    terrain->scaling = 2.0;
+    terrainClearPainting(terrain->height_map);
+    _checkBrushResult(terrain, &brush, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0);
+    terrainBrushFlatten(terrain->height_map, &brush_full, 2.0, 1.0);
+    _checkBrushResult(terrain, &brush, 1.1, 1.1, 1.1, 1.1, 1.1, 1.0, 0);
+    terrainBrushReset(terrain->height_map, &brush, 0.1);
+    _checkBrushResult(terrain, &brush, 1.099, 1.099, 1.099, 1.0995, 1.1, 1.0, 0);
 
     /* Tear down */
     _tearDownDefinition(terrain);
+
+    /* Test with scaling and the sinusoid setup (to test the basevalue sampling) */
+    terrain = _setUpDefinition();
+    terrain->height = 1.0;
+    terrain->scaling = 2.0;
+    _checkBrushResult(terrain, &brush, 0.0, 0.309016994375, 0.587785252292, 0.809016994375, 0.951056516295, 1.0, 1);
+    terrainBrushFlatten(terrain->height_map, &brush_full, 2.0, 1.0);
+    _checkBrushResultSides(terrain, &brush, 2.0, 2.0, 2.0, 2.0, 2.0, 1.0, 2.0, 2.0, 2.0, 2.0, -1.0);
+    terrainBrushReset(terrain->height_map, &brush, 1.0);
+    _checkBrushResultSides(terrain, &brush, 0.0, 0.309016994375, 0.587785252292, 2.0 - (2.0 - 0.809016994375) * 0.5, 2.0, 1.0, -0.309016994375, -0.587785252292, 2.0 - (2.0 + 0.809016994375) * 0.5, 2.0, -1.0);
+    _tearDownDefinition(terrain);
 }
 END_TEST