diff --git a/src/Base/Builder3D.cpp b/src/Base/Builder3D.cpp
index 11d5b5af2c..6ace7635ba 100644
--- a/src/Base/Builder3D.cpp
+++ b/src/Base/Builder3D.cpp
@@ -385,11 +385,13 @@ void InventorBuilder::addBaseColor(float color_r,float color_g,float color_b)
     result << Base::blanks(indent) << "} " << std::endl;
 }
 
-void InventorBuilder::addMaterial(float color_r,float color_g,float color_b)
+void InventorBuilder::addMaterial(float color_r,float color_g,float color_b,float color_a)
 {
     result << Base::blanks(indent) << "Material { " << std::endl;
     result << Base::blanks(indent) << "  diffuseColor "
            << color_r << " "<< color_g << " "<< color_b << std::endl;
+    if (color_a > 0)
+        result << Base::blanks(indent) << "  transparency " << color_a << std::endl;
     result << Base::blanks(indent) << "} " << std::endl;
 }
 
@@ -688,6 +690,29 @@ void InventorBuilder::addIndexedFaceSet(const std::vector<int>& indices)
     result << Base::blanks(indent) << "} " << std::endl;
 }
 
+void InventorBuilder::addFaceSet(const std::vector<int>& vertices)
+{
+    result << Base::blanks(indent) << "FaceSet { " << std::endl
+           << Base::blanks(indent) << "  numVertices [ " << std::endl;
+
+    indent += 4;
+    std::vector<int>::const_iterator it_last_f = vertices.end()-1;
+    int index=0;
+    for (std::vector<int>::const_iterator it = vertices.begin(); it != vertices.end(); ++it) {
+        if (index % 8 == 0)
+            result << Base::blanks(indent);
+        if (it != it_last_f)
+            result << *it << ", ";
+        else
+            result << *it << " ] " << std::endl;
+        if (++index % 8 == 0)
+            result << std::endl;
+    }
+    indent -= 4;
+
+    result << Base::blanks(indent) << "} " << std::endl;
+}
+
 void InventorBuilder::beginNormal()
 {
     result << Base::blanks(indent) << "Normal { " << std::endl;
diff --git a/src/Base/Builder3D.h b/src/Base/Builder3D.h
index b30665f34b..81454fb845 100644
--- a/src/Base/Builder3D.h
+++ b/src/Base/Builder3D.h
@@ -189,8 +189,9 @@ public:
      * \param color_r - red color
      * \param color_g - green color
      * \param color_b - blue color
+     * \param color_a - transparency
      */
-    void addMaterial(float color_r,float color_g,float color_b);
+    void addMaterial(float color_r,float color_g,float color_b,float color_a=0);
     /*!
      * \brief Starts a material node. The node must be closed with \ref endMaterial
      * and the colors must be added with \ref addColor().
@@ -291,6 +292,7 @@ public:
     void addSinglePlane(const Vector3f& base, const Vector3f& eX, const Vector3f& eY, float length, float width, bool filled = true,
                         short lineSize=2, float color_r=1.0,float color_g=1.0,float color_b=1.0);
     void addIndexedFaceSet(const std::vector<int>& indices);
+    void addFaceSet(const std::vector<int>& vertices);
     //@}
 
     /** @name Surface handling */