diff --git a/TODO b/TODO
index de3288f..75a95e9 100644
--- a/TODO
+++ b/TODO
@@ -10,6 +10,7 @@ Technology Preview 2 :
    => Push displaced polygons, but keep undisplaced coordinates for second pass.
    => Add detail texture.
    => Displacement on 3d explorer and previews.
+   => Optimize ray marching (for tracing and shadows), using base terrain and displacement power.
 - Fix rendering when inside a cloud layer, with other upper or lower layers.
 - Translations.
 
diff --git a/lib_paysages/renderer.c b/lib_paysages/renderer.c
index 25d5f67..4f56de2 100644
--- a/lib_paysages/renderer.c
+++ b/lib_paysages/renderer.c
@@ -73,6 +73,23 @@ static void _pushQuad(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, Ve
     renderer->pushTriangle(renderer, v4, v1, v3, callback, callback_data);
 }
 
+static void _pushDisplacedTriangle(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, Vector3 ov1, Vector3 ov2, Vector3 ov3, f_RenderFragmentCallback callback, void* callback_data)
+{
+    Vector3 p1, p2, p3;
+
+    p1 = renderer->projectPoint(renderer, v1);
+    p2 = renderer->projectPoint(renderer, v2);
+    p3 = renderer->projectPoint(renderer, v3);
+
+    renderPushTriangle(renderer->render_area, p1, p2, p3, ov1, ov2, ov3, callback, callback_data);
+}
+
+static void _pushDisplacedQuad(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, Vector3 v4, Vector3 ov1, Vector3 ov2, Vector3 ov3, Vector3 ov4, f_RenderFragmentCallback callback, void* callback_data)
+{
+    renderer->pushDisplacedTriangle(renderer, v2, v3, v1, ov2, ov3, ov1, callback, callback_data);
+    renderer->pushDisplacedTriangle(renderer, v4, v1, v3, ov4, ov1, ov3, callback, callback_data);
+}
+
 static RayCastingResult _rayWalking(Renderer* renderer, Vector3 location, Vector3 direction, int terrain, int water, int sky, int clouds)
 {
     return _RAYCASTING_NULL;
@@ -118,6 +135,8 @@ Renderer* rendererCreate()
     result->unprojectPoint = _unprojectPoint;
     result->pushTriangle = _pushTriangle;
     result->pushQuad = _pushQuad;
+    result->pushDisplacedTriangle = _pushDisplacedTriangle;
+    result->pushDisplacedQuad = _pushDisplacedQuad;
 
     result->rayWalking = _rayWalking;
 
diff --git a/lib_paysages/renderer.h b/lib_paysages/renderer.h
index 56b0e02..b6d7ef5 100644
--- a/lib_paysages/renderer.h
+++ b/lib_paysages/renderer.h
@@ -34,6 +34,8 @@ struct Renderer
     int (*addRenderProgress)(Renderer* renderer, double progress);
     void (*pushTriangle)(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, f_RenderFragmentCallback callback, void* callback_data);
     void (*pushQuad)(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, Vector3 v4, f_RenderFragmentCallback callback, void* callback_data);
+    void (*pushDisplacedTriangle)(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, Vector3 ov1, Vector3 ov2, Vector3 ov3, f_RenderFragmentCallback callback, void* callback_data);
+    void (*pushDisplacedQuad)(Renderer* renderer, Vector3 v1, Vector3 v2, Vector3 v3, Vector3 v4, Vector3 ov1, Vector3 ov2, Vector3 ov3, Vector3 ov4, f_RenderFragmentCallback callback, void* callback_data);
 
     /* Shortcuts */
     Color (*applyLightingToSurface)(Renderer* renderer, Vector3 location, Vector3 normal, SurfaceMaterial* material);
diff --git a/lib_paysages/terrain/raster.c b/lib_paysages/terrain/raster.c
index fa26ae8..7109435 100644
--- a/lib_paysages/terrain/raster.c
+++ b/lib_paysages/terrain/raster.c
@@ -31,21 +31,30 @@ static Color _postProcessFragment(Renderer* renderer, Vector3 point, void* data)
 
 static void _renderQuad(Renderer* renderer, double x, double z, double size, double water_height)
 {
-    Vector3 v1, v2, v3, v4;
+    Vector3 ov1, ov2, ov3, ov4;
+    Vector3 dv1, dv2, dv3, dv4;
 
-    /*v1 = _getPoint(definition, renderer, x, z);
-    v2 = _getPoint(definition, renderer, x, z + size);
-    v3 = _getPoint(definition, renderer, x + size, z + size);
-    v4 = _getPoint(definition, renderer, x + size, z);*/
+    ov1.y = ov2.y = ov3.y = ov4.y;
 
-    v1 = renderer->terrain->getResult(renderer, x, z, 1, 1).location;
-    v2 = renderer->terrain->getResult(renderer, x, z + size, 1, 1).location;
-    v3 = renderer->terrain->getResult(renderer, x + size, z + size, 1, 1).location;
-    v4 = renderer->terrain->getResult(renderer, x + size, z, 1, 1).location;
+    ov1.x = x;
+    ov1.z = z;
+    dv1 = renderer->terrain->getResult(renderer, x, z, 1, 1).location;
 
-    if (v1.y > water_height || v2.y > water_height || v3.y > water_height || v4.y > water_height)
+    ov2.x = x;
+    ov2.z = z + size;
+    dv2 = renderer->terrain->getResult(renderer, x, z + size, 1, 1).location;
+
+    ov3.x = x + size;
+    ov3.z = z + size;
+    dv3 = renderer->terrain->getResult(renderer, x + size, z + size, 1, 1).location;
+
+    ov4.x = x + size;
+    ov4.z = z;
+    dv4 = renderer->terrain->getResult(renderer, x + size, z, 1, 1).location;
+
+    if (dv1.y > water_height || dv2.y > water_height || dv3.y > water_height || dv4.y > water_height)
     {
-        renderer->pushQuad(renderer, v1, v2, v3, v4, _postProcessFragment, NULL);
+        renderer->pushDisplacedQuad(renderer, dv1, dv2, dv3, dv4, ov1, ov2, ov3, ov4, _postProcessFragment, NULL);
     }
 }