Added new osgVolume::VolumeScene and osgVolume::MultipassTechnique class shells that will be filled out to provide multi-pass volume rendering that handles mixing of

3D meshes with volume rendering and segmentation of volumes via a user defined hull mesh.

include/osgVolume/VolumeScene

@@ -0,0 +1,44 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2009 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSGVOLUMESCENE
+#define OSGVOLUMESCENE 1
+
+#include <osg/Group>
+#include <osgVolume/Export>
+
+namespace osgVolume {
+
+/** VolumeScene provides high level support for doing multi-pass rendering of volumes where the main scene to rendered to color and depth textures and then re-rendered for the purposes of volume rendering.*/
+class OSGVOLUME_EXPORT VolumeScene : public osg::Group
+{
+    public:
+
+        VolumeScene();
+
+        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
+        VolumeScene(const VolumeScene&,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+        META_Node(osgVolume, VolumeScene);
+
+        virtual void traverse(osg::NodeVisitor& nv);
+
+    protected:
+
+        virtual ~VolumeScene();
+
+};
+
+}
+
+#endif