Further work on osgShadow::ShadowTechnique API

include/osgShadow/ShadowVolume

@@ -30,9 +30,21 @@ class OSGSHADOW_EXPORT ShadowVolume : public ShadowTechnique
             
         META_Object(osgShadow, ShadowVolume);
         
+        /** initialize the ShadowedScene and local cached data structures.*/
+        virtual void init();
+        
+        /** run the update traversal of the ShadowedScene and update any loca chached data structures.*/
+        virtual void update(osg::NodeVisitor& nv);
+        
+        /** run the cull traversal of the ShadowedScene and set up the rendering for this ShadowTechnique.*/
+        virtual void cull(osg::NodeVisitor& nv);
+        
+        /** Clean scene graph from any shadow technique specific nodes, state and drawables.*/
+        virtual void cleanSceneGraph();
+
     protected :
 
-        virtual ~ShadowVolume() {}
+        virtual ~ShadowVolume();
         
 };