diff --git a/Apps/Tuto/stage_shader.cpp b/Apps/Tuto/stage_shader.cpp
index 2308d08b36abddae05397226201aabc2d021250f..f700af9b81d881908a36313eaea7fc33d3053f74 100644
--- a/Apps/Tuto/stage_shader.cpp
+++ b/Apps/Tuto/stage_shader.cpp
@@ -197,6 +197,96 @@ void StageShader::slot_doubleSpinBox_GridColor(double c)
 	updateGL();
 }
 
+void StageShader::slot_pushButton_addSphere()
+{
+	m_shader->setClipSpheresCount(dock.comboBox_SphereIndex->count() + 1);
+
+	m_shader->setClipSphereParamsCenter(m_bb.center(), dock.comboBox_SphereIndex->count() + 1 - 1);
+	m_shader->setClipSphereParamsRadius((m_bb.maxSize())*1.0, dock.comboBox_SphereIndex->count() + 1 - 1);
+
+	std::string indexStr;
+	std::stringstream ss;
+	ss << (dock.comboBox_PlaneIndex->count() + 1);
+	indexStr = ss.str();
+
+	std::string str = "Sphere " + indexStr;
+
+	dock.comboBox_SphereIndex->addItem(QString(str.c_str()));
+
+	dock.vertexEdit->setPlainText(QString(m_shader->getVertexShaderSrc()));
+	dock.fragmentEdit->setPlainText(QString(m_shader->getFragmentShaderSrc()));
+
+	updateGLMatrices();
+}
+
+void StageShader::slot_pushButton_deleteSphere()
+{
+	m_shader->setClipSpheresCount(dock.comboBox_SphereIndex->count() - 1);
+
+	dock.comboBox_SphereIndex->removeItem(dock.comboBox_SphereIndex->count() - 1);
+
+	dock.vertexEdit->setPlainText(QString(m_shader->getVertexShaderSrc()));
+	dock.fragmentEdit->setPlainText(QString(m_shader->getFragmentShaderSrc()));
+
+	updateGLMatrices();
+}
+
+void StageShader::slot_comboBox_SphereIndexChanged(int newIndex)
+{
+	if (newIndex >= 0)
+	{
+		Geom::Vec3f currSphereCenter = m_shader->getClipSphereParamsCenter(newIndex);
+		dock.doubleSpinBox_SphereCenterx->setValue(currSphereCenter[0]);
+		dock.doubleSpinBox_SphereCentery->setValue(currSphereCenter[1]);
+		dock.doubleSpinBox_SphereCenterz->setValue(currSphereCenter[2]);
+
+		dock.doubleSpinBox_SphereRadius->setValue(m_shader->getClipSphereParamsRadius(newIndex));
+	}
+}
+
+void StageShader::slot_doubleSpinBox_SphereCenter(double c)
+{
+	if (dock.comboBox_SphereIndex->currentIndex() >= 0)
+	{
+		float x = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->doubleSpinBox_SphereCenterx->value();
+		float y = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->doubleSpinBox_SphereCentery->value();
+		float z = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->doubleSpinBox_SphereCenterz->value();
+		m_shader->setClipSphereParamsCenter(Geom::Vec3f(x, y, z), dock.comboBox_SphereIndex->currentIndex());
+		updateGL();
+	}
+}
+
+void StageShader::slot_doubleSpinBox_SphereRadius(double c)
+{
+	if (dock.comboBox_SphereIndex->currentIndex() >= 0)
+	{
+		m_shader->setClipSphereParamsRadius((float)c, dock.comboBox_SphereIndex->currentIndex());
+		updateGL();
+	}
+}
+
+void StageShader::slot_spinBox_SphereGridResolutionX(int i)
+{
+	m_shader->setClipSpheresDisplayXRes((size_t)i);
+	updateGL();
+}
+
+void StageShader::slot_spinBox_SphereGridResolutionY(int i)
+{
+	m_shader->setClipSpheresDisplayYRes((size_t)i);
+	updateGL();
+}
+
+void StageShader::slot_doubleSpinBox_SphereGridColor(double c)
+{
+	float r = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->doubleSpinBox_SphereGridColorR->value();
+	float g = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->doubleSpinBox_SphereGridColorG->value();
+	float b = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->doubleSpinBox_SphereGridColorB->value();
+
+	m_shader->setClipSpheresDisplayColor(Geom::Vec3f(r, g, b));
+	updateGL();
+}
+
 void StageShader::button_compile()
 {
 	QString st1 = dynamic_cast<Utils::QT::uiDockInterface*>(dockWidget())->vertexEdit->toPlainText();
@@ -278,10 +368,37 @@ void StageShader::initGUI()
 	dock.doubleSpinBox_GridDisplaySize->setValue(m_shader->getClipPlanesDisplaySize());
 	dock.spinBox_GridResolutionX->setValue(m_shader->getClipPlanesDisplayXRes());
 	dock.spinBox_GridResolutionY->setValue(m_shader->getClipPlanesDisplayYRes());
-	Geom::Vec3f col = m_shader->getClipPlanesDisplayColor();
-	dock.doubleSpinBox_GridColorR->setValue(col[0]);
-	dock.doubleSpinBox_GridColorG->setValue(col[1]);
-	dock.doubleSpinBox_GridColorB->setValue(col[2]);
+	Geom::Vec3f planesCol = m_shader->getClipPlanesDisplayColor();
+	dock.doubleSpinBox_GridColorR->setValue(planesCol[0]);
+	dock.doubleSpinBox_GridColorG->setValue(planesCol[1]);
+	dock.doubleSpinBox_GridColorB->setValue(planesCol[2]);
+
+
+
+	setCallBack(dock.pushButton_addSphere, SIGNAL(clicked()), SLOT(slot_pushButton_addSphere()));
+	setCallBack(dock.pushButton_deleteSphere, SIGNAL(clicked()), SLOT(slot_pushButton_deleteSphere()));
+
+	setCallBack(dock.comboBox_SphereIndex, SIGNAL(currentIndexChanged(int)), SLOT(slot_comboBox_SphereIndexChanged(int)));
+
+	setCallBack(dock.doubleSpinBox_SphereCenterx, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereCenter(double)));
+	setCallBack(dock.doubleSpinBox_SphereCentery, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereCenter(double)));
+	setCallBack(dock.doubleSpinBox_SphereCenterz, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereCenter(double)));
+
+	setCallBack(dock.doubleSpinBox_SphereRadius, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereRadius(double)));
+
+	setCallBack(dock.spinBox_SphereGridResolutionX, SIGNAL(valueChanged(int)), SLOT(slot_spinBox_SphereGridResolutionX(int)));
+	setCallBack(dock.spinBox_SphereGridResolutionY, SIGNAL(valueChanged(int)), SLOT(slot_spinBox_SphereGridResolutionY(int)));
+	setCallBack(dock.doubleSpinBox_SphereGridColorR, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereGridColor(double)));
+	setCallBack(dock.doubleSpinBox_SphereGridColorG, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereGridColor(double)));
+	setCallBack(dock.doubleSpinBox_SphereGridColorB, SIGNAL(valueChanged(double)), SLOT(slot_doubleSpinBox_SphereGridColor(double)));
+
+	dock.spinBox_SphereGridResolutionX->setValue(m_shader->getClipSpheresDisplayXRes());
+	dock.spinBox_SphereGridResolutionY->setValue(m_shader->getClipSpheresDisplayYRes());
+	Geom::Vec3f spheresCol = m_shader->getClipSpheresDisplayColor();
+	dock.doubleSpinBox_SphereGridColorR->setValue(spheresCol[0]);
+	dock.doubleSpinBox_SphereGridColorG->setValue(spheresCol[1]);
+	dock.doubleSpinBox_SphereGridColorB->setValue(spheresCol[2]);
+
 }
 
 void StageShader::cb_Open()
@@ -367,11 +484,15 @@ void StageShader::cb_initGL()
 
 	registerShader(m_shader);
 
+	m_shader->insertClippingCode();
+
 	m_shader->setClipPlanesDisplayColor(Geom::Vec3f (1.0, 0.0, 0.0));
 	m_shader->setClipPlanesDisplayXRes(10);
 	m_shader->setClipPlanesDisplayYRes(5);
 
-	m_shader->insertClippingCode();
+	m_shader->setClipSpheresDisplayColor(Geom::Vec3f(0.0, 0.4, 1.0));
+	m_shader->setClipSpheresDisplayXRes(20);
+	m_shader->setClipSpheresDisplayYRes(15);
 }
 
 void StageShader::updateVBOprimitives(int upType)
@@ -422,6 +543,7 @@ void StageShader::cb_redraw()
 		m_render_topo->drawTopo();
 
 	m_shader->displayClipPlanes();
+	m_shader->displayClipSpheres();
 
 }
 
diff --git a/Apps/Tuto/stage_shader.h b/Apps/Tuto/stage_shader.h
index 1b4c1edfff62762926a5f609738af216a7e2ac19..a01e9f5c39deee6669771f962fce6c79e4fcc11d 100644
--- a/Apps/Tuto/stage_shader.h
+++ b/Apps/Tuto/stage_shader.h
@@ -139,6 +139,18 @@ public slots:
 	void slot_spinBox_GridResolutionY(int i);
 	void slot_doubleSpinBox_GridColor(double c);
 
+	void slot_pushButton_addSphere();
+	void slot_pushButton_deleteSphere();
+
+	void slot_comboBox_SphereIndexChanged(int newIndex);
+
+	void slot_doubleSpinBox_SphereCenter(double c);
+	void slot_doubleSpinBox_SphereRadius(double c);
+
+	void slot_spinBox_SphereGridResolutionX(int i);
+	void slot_spinBox_SphereGridResolutionY(int i);
+	void slot_doubleSpinBox_SphereGridColor(double c);
+
 	void button_compile();
 };
 
diff --git a/Apps/Tuto/stage_shader.ui b/Apps/Tuto/stage_shader.ui
index 4d98b137310fca8f4134ab939a66d0daa874e132..813aa15d845ced50fc68206d9725f013a392bdb0 100644
--- a/Apps/Tuto/stage_shader.ui
+++ b/Apps/Tuto/stage_shader.ui
@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>417</width>
+    <width>424</width>
     <height>534</height>
    </rect>
   </property>
@@ -34,7 +34,7 @@
         <item row="0" column="0">
          <widget class="QTabWidget" name="tabWidget_3">
           <property name="currentIndex">
-           <number>1</number>
+           <number>2</number>
           </property>
           <widget class="QWidget" name="tab_Object">
            <attribute name="title">
@@ -203,13 +203,13 @@
           </widget>
           <widget class="QWidget" name="tab_Clipping">
            <attribute name="title">
-            <string>Clipping</string>
+            <string>Plane Clipping</string>
            </attribute>
            <layout class="QVBoxLayout" name="verticalLayout_4">
             <item>
              <layout class="QVBoxLayout" name="verticalLayout_3" stretch="3,1,2">
               <item>
-               <widget class="QGroupBox" name="groupBox_DisplayParams">
+               <widget class="QGroupBox" name="groupBox_PlanesDisplayParams">
                 <property name="enabled">
                  <bool>true</bool>
                 </property>
@@ -523,6 +523,225 @@
             </item>
            </layout>
           </widget>
+          <widget class="QWidget" name="tab_5">
+           <attribute name="title">
+            <string>Sphere Clipping</string>
+           </attribute>
+           <layout class="QHBoxLayout" name="horizontalLayout_5">
+            <item>
+             <layout class="QVBoxLayout" name="verticalLayout_5" stretch="3,1,2">
+              <item>
+               <widget class="QGroupBox" name="groupBox_SpheresDisplayParams">
+                <property name="enabled">
+                 <bool>true</bool>
+                </property>
+                <property name="title">
+                 <string>Display Parameters</string>
+                </property>
+                <layout class="QHBoxLayout" name="horizontalLayout_3">
+                 <item>
+                  <layout class="QGridLayout" name="gridLayout_13">
+                   <item row="1" column="2">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereGridColorG">
+                     <property name="maximum">
+                      <double>1.000000000000000</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="0" column="0">
+                    <widget class="QLabel" name="label_SphereGridResolution">
+                     <property name="text">
+                      <string>Res.</string>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="0" column="1">
+                    <widget class="QSpinBox" name="spinBox_SphereGridResolutionX">
+                     <property name="maximum">
+                      <number>200</number>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="1" column="0">
+                    <widget class="QLabel" name="label_GridColor_2">
+                     <property name="text">
+                      <string>Color</string>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="1" column="3">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereGridColorB">
+                     <property name="maximum">
+                      <double>1.000000000000000</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="1" column="1">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereGridColorR">
+                     <property name="maximum">
+                      <double>1.000000000000000</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="0" column="2">
+                    <widget class="QSpinBox" name="spinBox_SphereGridResolutionY">
+                     <property name="maximum">
+                      <number>200</number>
+                     </property>
+                    </widget>
+                   </item>
+                  </layout>
+                 </item>
+                </layout>
+               </widget>
+              </item>
+              <item>
+               <widget class="QGroupBox" name="groupBox_SpheresSelection_2">
+                <property name="title">
+                 <string>Spheres Selection</string>
+                </property>
+                <widget class="QPushButton" name="pushButton_deleteSphere">
+                 <property name="geometry">
+                  <rect>
+                   <x>170</x>
+                   <y>30</y>
+                   <width>31</width>
+                   <height>28</height>
+                  </rect>
+                 </property>
+                 <property name="text">
+                  <string>-</string>
+                 </property>
+                </widget>
+                <widget class="QPushButton" name="pushButton_addSphere">
+                 <property name="geometry">
+                  <rect>
+                   <x>140</x>
+                   <y>30</y>
+                   <width>31</width>
+                   <height>28</height>
+                  </rect>
+                 </property>
+                 <property name="text">
+                  <string>+</string>
+                 </property>
+                </widget>
+                <widget class="QComboBox" name="comboBox_SphereIndex">
+                 <property name="enabled">
+                  <bool>true</bool>
+                 </property>
+                 <property name="geometry">
+                  <rect>
+                   <x>10</x>
+                   <y>30</y>
+                   <width>99</width>
+                   <height>28</height>
+                  </rect>
+                 </property>
+                 <property name="focusPolicy">
+                  <enum>Qt::NoFocus</enum>
+                 </property>
+                 <property name="editable">
+                  <bool>false</bool>
+                 </property>
+                 <property name="currentIndex">
+                  <number>-1</number>
+                 </property>
+                </widget>
+               </widget>
+              </item>
+              <item>
+               <widget class="QGroupBox" name="groupBox_SphereParams">
+                <property name="title">
+                 <string>Sphere Params</string>
+                </property>
+                <layout class="QHBoxLayout" name="horizontalLayout_4">
+                 <item>
+                  <layout class="QGridLayout" name="gridLayout_14">
+                   <item row="0" column="1">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereCenterx">
+                     <property name="minimum">
+                      <double>-99.989999999999995</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                     <property name="value">
+                      <double>0.000000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="0" column="2">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereCentery">
+                     <property name="minimum">
+                      <double>-99.989999999999995</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                     <property name="value">
+                      <double>0.000000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="0" column="3">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereCenterz">
+                     <property name="minimum">
+                      <double>-99.989999999999995</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                     <property name="value">
+                      <double>0.000000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="1" column="1">
+                    <widget class="QDoubleSpinBox" name="doubleSpinBox_SphereRadius">
+                     <property name="minimum">
+                      <double>-99.989999999999995</double>
+                     </property>
+                     <property name="singleStep">
+                      <double>0.100000000000000</double>
+                     </property>
+                     <property name="value">
+                      <double>0.000000000000000</double>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="0" column="0">
+                    <widget class="QLabel" name="label_SphereCenter">
+                     <property name="text">
+                      <string>Center</string>
+                     </property>
+                    </widget>
+                   </item>
+                   <item row="1" column="0">
+                    <widget class="QLabel" name="label_SphereRadius">
+                     <property name="text">
+                      <string>Radius</string>
+                     </property>
+                    </widget>
+                   </item>
+                  </layout>
+                 </item>
+                </layout>
+               </widget>
+              </item>
+             </layout>
+            </item>
+           </layout>
+          </widget>
          </widget>
         </item>
        </layout>
diff --git a/src/Utils/clippingShader.cpp b/src/Utils/clippingShader.cpp
index 98055e578fb61c5d404972b6724c01a74d03cb17..8c256b1d82986d01e35db9a1b2026d91a9a68ad9 100644
--- a/src/Utils/clippingShader.cpp
+++ b/src/Utils/clippingShader.cpp
@@ -713,6 +713,7 @@ void ClippingShader::updateClipSphereVBO(int sphereIndex)
 
 	m_clipSpheresDrawers[sphereIndex]->begin(GL_LINES);
 
+	// Compute angle displacement steps
 	float dTheta = 0.0;
 	if (m_clipSpheresDisplayXRes != 0)
 		dTheta = 2 * M_PI / (float)m_clipSpheresDisplayXRes;
@@ -720,28 +721,38 @@ void ClippingShader::updateClipSphereVBO(int sphereIndex)
 	if (m_clipSpheresDisplayYRes != 0)
 		dPhi = M_PI / (float)m_clipSpheresDisplayYRes;
 
+	// Draw the sphere in wireframe
 	for (size_t i = 0; i < m_clipSpheresDisplayXRes; i++)
 	{
 		for (size_t j = 0; j < m_clipSpheresDisplayYRes; j++)
 		{
+			// Compute 3 points according to the parametric equation of the sphere
 			Geom::Vec3f p1 (
-					m_clipSpheres[sphereIndex].radius * cos(i*dTheta) * sin(j*dPhi),
-					m_clipSpheres[sphereIndex].radius * sin(i*dTheta) * sin(j*dPhi),
-					m_clipSpheres[sphereIndex].radius * cos(j*dPhi));
-
+					cos(i*dTheta) * sin(j*dPhi),
+					sin(i*dTheta) * sin(j*dPhi),
+					cos(j*dPhi));
 			Geom::Vec3f p2 (
-					m_clipSpheres[sphereIndex].radius * cos((i+1)*dTheta) * sin(j*dPhi),
-					m_clipSpheres[sphereIndex].radius * sin((i+1)*dTheta) * sin(j*dPhi),
-					m_clipSpheres[sphereIndex].radius * cos(j*dPhi));
-
+					cos((i+1)*dTheta) * sin(j*dPhi),
+					sin((i+1)*dTheta) * sin(j*dPhi),
+					cos(j*dPhi));
 			Geom::Vec3f p3 (
-					m_clipSpheres[sphereIndex].radius * cos(i*dTheta) * sin((j+1)*dPhi),
-					m_clipSpheres[sphereIndex].radius * sin(i*dTheta) * sin((j+1)*dPhi),
-					m_clipSpheres[sphereIndex].radius * cos((j+1)*dPhi));
+					cos(i*dTheta) * sin((j+1)*dPhi),
+					sin(i*dTheta) * sin((j+1)*dPhi),
+					cos((j+1)*dPhi));
+
+			// Scale with the radius
+			p1 *= m_clipSpheres[sphereIndex].radius;
+			p2 *= m_clipSpheres[sphereIndex].radius;
+			p3 *= m_clipSpheres[sphereIndex].radius;
 
+			// Translate to the center
+			p1 += m_clipSpheres[sphereIndex].center;
+			p2 += m_clipSpheres[sphereIndex].center;
+			p3 += m_clipSpheres[sphereIndex].center;
+
+			// Draw two lines with the 3 points
 			m_clipSpheresDrawers[sphereIndex]->vertex(p1);
 			m_clipSpheresDrawers[sphereIndex]->vertex(p2);
-
 			m_clipSpheresDrawers[sphereIndex]->vertex(p1);
 			m_clipSpheresDrawers[sphereIndex]->vertex(p3);
 		}
@@ -900,9 +911,9 @@ bool ClippingShader::insertClippingCode()
 	"				{\n"
 	"					// Keep the distance to the nearest sphere\n"
 	"					if (minDistanceToClipping < 0.0)\n"
-	"						minDistanceToClipping = distanceToSphere;\n"
+	"						minDistanceToClipping = -distanceToSphere;\n"
 	"					else\n"
-	"						minDistanceToClipping = min(minDistanceToClipping, distanceToSphere);\n"
+	"						minDistanceToClipping = min(minDistanceToClipping, -distanceToSphere);\n"
 	"				}\n"
 	"			}\n"
 	"\n"