diff --git a/src/definition/CameraDefinition.h b/src/definition/CameraDefinition.h
index f93fd55..2daddf6 100644
--- a/src/definition/CameraDefinition.h
+++ b/src/definition/CameraDefinition.h
@@ -39,6 +39,8 @@ public:
     inline const Matrix4 &getTransformationMatrix() const {return projector;}
     inline VectorSpherical getDirectionSpherical() const {return direction;}
     inline CameraPerspective getPerspective() const {return perspective;}
+    inline double getWidth() const {return width;}
+    inline double getHeight() const {return height;}
 
     double getRealDepth(const Vector3 &projected) const;
 
diff --git a/src/interface/modeler/quickapp/OpenGLView.cpp b/src/interface/modeler/quickapp/OpenGLView.cpp
index e1a90f8..04f47a5 100644
--- a/src/interface/modeler/quickapp/OpenGLView.cpp
+++ b/src/interface/modeler/quickapp/OpenGLView.cpp
@@ -14,6 +14,7 @@ OpenGLView::OpenGLView(QQuickItem *parent) :
     renderer = NULL;
 
     setAcceptedMouseButtons(Qt::AllButtons);
+    setAcceptHoverEvents(true);
 
     mouse_button = Qt::NoButton;
 
@@ -120,6 +121,13 @@ void OpenGLView::mouseMoveEvent(QMouseEvent *event)
         window->getCamera()->processScroll(-0.02 * factor * diff.x(), 0.02 * factor * diff.y());
     }
     mouse_pos = event->windowPos();
+
+    renderer->setMouseLocation(event->pos().x(), height() - event->pos().y());
+}
+
+void OpenGLView::hoverMoveEvent(QHoverEvent *event)
+{
+    renderer->setMouseLocation(event->pos().x(), height() - event->pos().y());
 }
 
 void OpenGLView::timerEvent(QTimerEvent *)
diff --git a/src/interface/modeler/quickapp/OpenGLView.h b/src/interface/modeler/quickapp/OpenGLView.h
index 58f2075..f007004 100644
--- a/src/interface/modeler/quickapp/OpenGLView.h
+++ b/src/interface/modeler/quickapp/OpenGLView.h
@@ -24,6 +24,7 @@ protected:
     virtual void mousePressEvent(QMouseEvent *event) override;
     virtual void mouseReleaseEvent(QMouseEvent *event) override;
     virtual void mouseMoveEvent(QMouseEvent *event) override;
+    virtual void hoverMoveEvent(QHoverEvent *event) override;
     virtual void timerEvent(QTimerEvent *event) override;
 
 private:
diff --git a/src/render/opengl/OpenGLRenderer.cpp b/src/render/opengl/OpenGLRenderer.cpp
index a2a3ae8..c3b8c65 100644
--- a/src/render/opengl/OpenGLRenderer.cpp
+++ b/src/render/opengl/OpenGLRenderer.cpp
@@ -10,6 +10,7 @@
 #include "Scenery.h"
 #include "LightingManager.h"
 #include "Logs.h"
+#include "Vector3.h"
 
 #include "GL/glu.h" // TEMP
 
@@ -21,6 +22,13 @@ OpenGLRenderer::OpenGLRenderer(Scenery* scenery):
     vp_width = 1;
     vp_height = 1;
 
+    mouse_tracking = true;
+    mouse_x = 0;
+    mouse_y = 0;
+    mouse_projected = new Vector3();
+
+    view_matrix = new QMatrix4x4;
+
     render_quality = 3;
 
     functions = new OpenGLFunctions();
@@ -40,6 +48,10 @@ OpenGLRenderer::~OpenGLRenderer()
     water->interrupt();
     skybox->interrupt();
 
+    delete mouse_projected;
+
+    delete view_matrix;
+
     delete skybox;
     delete water;
     delete terrain;
@@ -140,6 +152,11 @@ void OpenGLRenderer::paint()
         terrain->render();
         water->render();
 
+        if (mouse_tracking)
+        {
+            updateMouseProjection();
+        }
+
         int error_code;
         while ((error_code = glGetError()) != GL_NO_ERROR)
         {
@@ -172,6 +189,17 @@ void OpenGLRenderer::resume()
     terrain->resume();
 }
 
+void OpenGLRenderer::setMouseLocation(int x, int y)
+{
+    mouse_x = x;
+    mouse_y = y;
+}
+
+const Vector3 &OpenGLRenderer::getMouseProjection()
+{
+    return *mouse_projected;
+}
+
 void OpenGLRenderer::cameraChangeEvent(CameraDefinition *camera)
 {
     // Get camera info
@@ -191,9 +219,11 @@ void OpenGLRenderer::cameraChangeEvent(CameraDefinition *camera)
     projection.setToIdentity();
     projection.perspective(perspective.yfov * 180.0 / M_PI, perspective.xratio, perspective.znear, perspective.zfar);
 
+    *view_matrix = projection * transform;
+
     // Set in shaders
     shared_state->set("cameraLocation", location);
-    shared_state->set("viewMatrix", projection * transform);
+    shared_state->set("viewMatrix", *view_matrix);
 }
 
 double OpenGLRenderer::getPrecision(const Vector3 &)
@@ -205,3 +235,15 @@ Color OpenGLRenderer::applyMediumTraversal(Vector3, Color color)
 {
     return color;
 }
+
+void OpenGLRenderer::updateMouseProjection()
+{
+    GLfloat z;
+    functions->glReadPixels(mouse_x, mouse_y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &z);
+
+    QVector4D located(mouse_x / render_camera->getWidth(), mouse_y / render_camera->getHeight(), z, 1.0);
+    QVector4D unprojected = view_matrix->inverted() * 2.0 * (located - QVector4D(0.5, 0.5, 0.5, 0.5));
+    *mouse_projected = Vector3(unprojected.x() / unprojected.w(), unprojected.y() / unprojected.w(), unprojected.z() / unprojected.w());
+
+    shared_state->set("mouseProjection", *mouse_projected);
+}
diff --git a/src/render/opengl/OpenGLRenderer.h b/src/render/opengl/OpenGLRenderer.h
index 0d0de51..265cca6 100644
--- a/src/render/opengl/OpenGLRenderer.h
+++ b/src/render/opengl/OpenGLRenderer.h
@@ -5,6 +5,8 @@
 
 #include "SoftwareRenderer.h"
 
+class QMatrix4x4;
+
 namespace paysages {
 namespace opengl {
 
@@ -42,6 +44,16 @@ public:
      */
     void resume();
 
+    /**
+     * Set the current mouse location, for use by getMouseProjection().
+     */
+    void setMouseLocation(int x, int y);
+
+    /**
+     * Get the coordinates of the mouse, projected in world space.
+     */
+    const Vector3 &getMouseProjection();
+
     /**
      * Change the camera location.
      */
@@ -54,12 +66,25 @@ public:
     virtual double getPrecision(const Vector3 &location) override;
     virtual Color applyMediumTraversal(Vector3 location, Color color) override;
 
+private:
+    /**
+     * Update the mouse_projected member.
+     */
+    void updateMouseProjection();
+
 private:
     bool ready;
     bool paused;
     int vp_width;
     int vp_height;
 
+    bool mouse_tracking;
+    int mouse_x;
+    int mouse_y;
+    Vector3 *mouse_projected;
+
+    QMatrix4x4 *view_matrix;
+
     OpenGLFunctions* functions;
     OpenGLSharedState* shared_state;
 
diff --git a/src/render/opengl/OpenGLTerrain.cpp b/src/render/opengl/OpenGLTerrain.cpp
index ee6aee2..8df2fd8 100644
--- a/src/render/opengl/OpenGLTerrain.cpp
+++ b/src/render/opengl/OpenGLTerrain.cpp
@@ -63,6 +63,7 @@ void OpenGLTerrain::initialize()
     program->addFragmentSource("atmosphere");
     program->addFragmentSource("tonemapping");
     program->addFragmentSource("fadeout");
+    program->addFragmentSource("ui");
     program->addFragmentSource("terrain");
 
     // Add terrain chunks
diff --git a/src/render/opengl/OpenGLWater.cpp b/src/render/opengl/OpenGLWater.cpp
index 81c6289..5406e1e 100644
--- a/src/render/opengl/OpenGLWater.cpp
+++ b/src/render/opengl/OpenGLWater.cpp
@@ -30,6 +30,7 @@ void OpenGLWater::initialize()
     program->addFragmentSource("atmosphere");
     program->addFragmentSource("tonemapping");
     program->addFragmentSource("fadeout");
+    program->addFragmentSource("ui");
     program->addFragmentSource("noise");
     program->addFragmentSource("water");
 
diff --git a/src/render/opengl/shaders/resources.qrc b/src/render/opengl/shaders/resources.qrc
index ed4c445..68f3f23 100644
--- a/src/render/opengl/shaders/resources.qrc
+++ b/src/render/opengl/shaders/resources.qrc
@@ -10,5 +10,6 @@
         <file>terrain.vert</file>
         <file>fadeout.frag</file>
         <file>noise.frag</file>
+        <file>ui.frag</file>
     </qresource>
 </RCC>
diff --git a/src/render/opengl/shaders/terrain.frag b/src/render/opengl/shaders/terrain.frag
index de2f60c..5343e7f 100644
--- a/src/render/opengl/shaders/terrain.frag
+++ b/src/render/opengl/shaders/terrain.frag
@@ -9,5 +9,7 @@ void main(void)
 
     gl_FragColor = applyToneMapping(gl_FragColor);
 
+    gl_FragColor = applyMouseTracking(unprojected, gl_FragColor);
+
     gl_FragColor.a = distanceFadeout();
 }
diff --git a/src/render/opengl/shaders/ui.frag b/src/render/opengl/shaders/ui.frag
new file mode 100644
index 0000000..1c399a8
--- /dev/null
+++ b/src/render/opengl/shaders/ui.frag
@@ -0,0 +1,14 @@
+uniform vec3 mouseProjection;
+
+vec4 applyMouseTracking(vec3 location, vec4 color)
+{
+    float dist = length(location - mouseProjection);
+    if (dist > 2.0)
+    {
+        return color;
+    }
+    else
+    {
+        return mix(color, vec4(1.0, 0.0, 0.0, 1.0), 1.0 - dist / 2.0);
+    }
+}
diff --git a/src/render/opengl/shaders/water.frag b/src/render/opengl/shaders/water.frag
index d6b5279..4a873a3 100644
--- a/src/render/opengl/shaders/water.frag
+++ b/src/render/opengl/shaders/water.frag
@@ -15,5 +15,7 @@ void main(void)
 
     gl_FragColor = applyToneMapping(gl_FragColor);
 
+    gl_FragColor = applyMouseTracking(unprojected, gl_FragColor);
+
     gl_FragColor.a = distanceFadeout();
 }