diff --git a/src/osgPlugins/osgSim/CMakeLists.txt b/src/osgPlugins/osgSim/CMakeLists.txt
index ead995379..f747139c1 100644
--- a/src/osgPlugins/osgSim/CMakeLists.txt
+++ b/src/osgPlugins/osgSim/CMakeLists.txt
@@ -6,6 +6,7 @@ SET(TARGET_SRC
     IO_LightPoint.cpp
     IO_LightPointNode.cpp
     IO_MultiSwitch.cpp
+    IO_OverlayNode.cpp
     IO_Sector.cpp
     IO_VisibilityGroup.cpp
     IO_ObjectRecordData.cpp
diff --git a/src/osgPlugins/osgSim/IO_OverlayNode.cpp b/src/osgPlugins/osgSim/IO_OverlayNode.cpp
new file mode 100644
index 000000000..23a839cea
--- /dev/null
+++ b/src/osgPlugins/osgSim/IO_OverlayNode.cpp
@@ -0,0 +1,131 @@
+#include <osgSim/OverlayNode>
+#include <osg/io_utils>
+
+#include <osgDB/Registry>
+#include <osgDB/Input>
+#include <osgDB/Output>
+
+using namespace osg;
+using namespace osgDB;
+using namespace osgSim;
+
+// forward declare functions to use later.
+bool OverlayNode_readLocalData(Object& obj, Input& fr);
+bool OverlayNode_writeLocalData(const Object& obj, Output& fw);
+
+// register the read and write functions with the osgDB::Registry.
+RegisterDotOsgWrapperProxy g_OverlayNodeProxy
+(
+    new OverlayNode,
+    "OverlayNode",
+    "Object Node OverlayNode Group",
+    &OverlayNode_readLocalData,
+    &OverlayNode_writeLocalData
+);
+
+bool OverlayNode_readLocalData(Object& obj, Input& fr)
+{
+    bool iteratorAdvanced = false;
+
+    OverlayNode& es = static_cast<OverlayNode&>(obj);
+
+    if (fr.matchSequence("technique"))
+    {
+        if (fr[1].matchWord("OBJECT_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY"))
+        {
+            es.setOverlayTechnique(OverlayNode::OBJECT_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY);
+            iteratorAdvanced = true;
+            fr+=2;
+        }
+        else if (fr[1].matchWord("VIEW_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY"))
+        {
+            es.setOverlayTechnique(OverlayNode::VIEW_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY);
+            iteratorAdvanced = true;
+            fr+=2;
+        }
+        else if (fr[1].matchWord("VIEW_DEPENDENT_WITH_PERSPECTIVE_OVERLAY"))
+        {
+            es.setOverlayTechnique(OverlayNode::VIEW_DEPENDENT_WITH_PERSPECTIVE_OVERLAY);
+            iteratorAdvanced = true;
+            fr+=2;
+        }
+    }
+
+    osg::Vec4 vec4(0.0f,0.0f,0.0f,1.0f);
+
+    if (fr[0].matchWord("clear_color") &&
+        fr[1].getFloat(vec4[0]) &&
+        fr[2].getFloat(vec4[1]) &&
+        fr[3].getFloat(vec4[2]) &&
+        fr[4].getFloat(vec4[3]))
+    {
+        es.setOverlayClearColor(vec4);
+        fr+=5;
+        iteratorAdvanced = true;
+    }
+
+    if (fr[0].matchWord("texture_size_hint"))
+    {
+        if (fr[1].isUInt())
+        {
+            unsigned int value=0;
+            fr[1].getUInt(value);
+            es.setOverlayTextureSizeHint(value);
+            iteratorAdvanced = true;
+            fr+=2;
+        }
+    }
+
+    if (fr[0].matchWord("texture_unit"))
+    {
+        if (fr[1].isUInt())
+        {
+            unsigned int value=0;
+            fr[1].getUInt(value);
+            es.setOverlayTextureUnit(value);
+            iteratorAdvanced = true;
+            fr+=2;
+        }
+    }
+
+    if (fr[0].matchWord("subgraph"))
+    {
+        fr+=1;
+        es.setOverlaySubgraph(fr.readNode());
+        iteratorAdvanced = true;
+    }
+
+    return iteratorAdvanced;
+}
+
+
+bool OverlayNode_writeLocalData(const Object& obj, Output& fw)
+{
+    const OverlayNode& es = static_cast<const OverlayNode&>(obj);
+
+    fw.indent() << "technique ";
+    if (es.getOverlayTechnique() == OverlayNode::OBJECT_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY)
+    {
+        fw<<"OBJECT_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY"<< std::endl;
+    }
+    else if (es.getOverlayTechnique() == OverlayNode::VIEW_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY)
+    {
+        fw<<"VIEW_DEPENDENT_WITH_ORTHOGRAPHIC_OVERLAY"<< std::endl;
+    }
+    else if (es.getOverlayTechnique() == OverlayNode::VIEW_DEPENDENT_WITH_PERSPECTIVE_OVERLAY)
+    {
+        fw<<"VIEW_DEPENDENT_WITH_PERSPECTIVE_OVERLAY"<< std::endl;
+    }
+    else
+    {
+        fw<<"UNKNOWN"<< std::endl;
+    }
+
+    fw.indent() << "clear_color "<<es.getOverlayClearColor()<< std::endl;
+    fw.indent() << "texture_size_hint " << es.getOverlayTextureSizeHint() << std::endl;
+    fw.indent() << "texture_unit " << es.getOverlayTextureUnit() << std::endl;
+    fw.indent() << "subgraph " ;
+    fw.writeObject(*es.getOverlaySubgraph());
+
+    return true;
+}