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.

src/osgVolume/CMakeLists.txt

@@ -12,10 +12,12 @@ SET(TARGET_H
     ${HEADER_PATH}/FixedFunctionTechnique
     ${HEADER_PATH}/Layer
     ${HEADER_PATH}/Locator
+    ${HEADER_PATH}/MultipassTechnique
     ${HEADER_PATH}/Property
     ${HEADER_PATH}/RayTracedTechnique
     ${HEADER_PATH}/Version
     ${HEADER_PATH}/Volume
+    ${HEADER_PATH}/VolumeScene
     ${HEADER_PATH}/VolumeTechnique
     ${HEADER_PATH}/VolumeTile
 )
@@ -25,17 +27,19 @@ SET(TARGET_SRC
     FixedFunctionTechnique.cpp
     Layer.cpp
     Locator.cpp
+    MultipassTechnique.cpp
     Property.cpp
     RayTracedTechnique.cpp
     Version.cpp
     Volume.cpp
+    VolumeScene.cpp
     VolumeTechnique.cpp
     VolumeTile.cpp
     ${OPENSCENEGRAPH_VERSIONINFO_RC}
 )
 
 
-SET(TARGET_LIBRARIES 
+SET(TARGET_LIBRARIES
     osgUtil
     osgDB
     osgGA

src/osgVolume/MultipassTechnique.cpp

@@ -0,0 +1,124 @@
+/* -*-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.
+*/
+
+#include <osgVolume/MultipassTechnique>
+#include <osgVolume/VolumeTile>
+
+#include <osg/Geometry>
+#include <osg/io_utils>
+
+#include <osg/Program>
+#include <osg/TexGen>
+#include <osg/Texture1D>
+#include <osg/Texture2D>
+#include <osg/Texture3D>
+#include <osg/TransferFunction>
+
+#include <osgDB/ReadFile>
+#include <osgDB/WriteFile>
+
+namespace osgVolume
+{
+
+
+MultipassTechnique::MultipassTechnique()
+{
+}
+
+MultipassTechnique::MultipassTechnique(const MultipassTechnique& fft,const osg::CopyOp& copyop):
+    VolumeTechnique(fft,copyop)
+{
+}
+
+MultipassTechnique::~MultipassTechnique()
+{
+}
+
+void MultipassTechnique::init()
+{
+    OSG_INFO<<"MultipassTechnique::init()"<<std::endl;
+
+    if (!_volumeTile)
+    {
+        OSG_NOTICE<<"MultipassTechnique::init(), error no volume tile assigned."<<std::endl;
+        return;
+    }
+
+    if (_volumeTile->getLayer()==0)
+    {
+        OSG_NOTICE<<"MultipassTechnique::init(), error no layer assigend to volume tile."<<std::endl;
+        return;
+    }
+
+    if (_volumeTile->getLayer()->getImage()==0)
+    {
+        OSG_NOTICE<<"MultipassTechnique::init(), error no image assigned to layer."<<std::endl;
+        return;
+    }
+
+    OSG_NOTICE<<"MultipassTechnique::init() Need to set up"<<std::endl;
+}
+
+void MultipassTechnique::update(osgUtil::UpdateVisitor* /*uv*/)
+{
+//    OSG_NOTICE<<"MultipassTechnique:update(osgUtil::UpdateVisitor* nv):"<<std::endl;
+}
+
+void MultipassTechnique::cull(osgUtil::CullVisitor* cv)
+{
+    OSG_NOTICE<<"MultipassTechnique::cull() Need to set up"<<std::endl;
+}
+
+void MultipassTechnique::cleanSceneGraph()
+{
+    OSG_NOTICE<<"MultipassTechnique::cleanSceneGraph()"<<std::endl;
+}
+
+void MultipassTechnique::traverse(osg::NodeVisitor& nv)
+{
+    // OSG_NOTICE<<"MultipassTechnique::traverse(osg::NodeVisitor& nv)"<<std::endl;
+    if (!_volumeTile) return;
+
+    // if app traversal update the frame count.
+    if (nv.getVisitorType()==osg::NodeVisitor::UPDATE_VISITOR)
+    {
+        if (_volumeTile->getDirty()) _volumeTile->init();
+
+        osgUtil::UpdateVisitor* uv = dynamic_cast<osgUtil::UpdateVisitor*>(&nv);
+        if (uv)
+        {
+            update(uv);
+            return;
+        }
+
+    }
+    else if (nv.getVisitorType()==osg::NodeVisitor::CULL_VISITOR)
+    {
+        osgUtil::CullVisitor* cv = dynamic_cast<osgUtil::CullVisitor*>(&nv);
+        if (cv)
+        {
+            cull(cv);
+            return;
+        }
+    }
+
+
+    if (_volumeTile->getDirty())
+    {
+        OSG_INFO<<"******* Doing init ***********"<<std::endl;
+        _volumeTile->init();
+    }
+}
+
+
+} // end of osgVolume namespace

src/osgVolume/VolumeScene.cpp

@@ -0,0 +1,36 @@
+/* -*-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.
+*/
+
+#include <osgVolume/VolumeScene>
+#include <OpenThreads/ScopedLock>
+
+using namespace osgVolume;
+
+VolumeScene::VolumeScene()
+{
+}
+
+VolumeScene::VolumeScene(const VolumeScene& vs, const osg::CopyOp& copyop):
+    osg::Group(vs,copyop)
+{
+}
+
+
+VolumeScene::~VolumeScene()
+{
+}
+
+void VolumeScene::traverse(osg::NodeVisitor& nv)
+{
+    Group::traverse(nv);
+}