Began work on providing support for threading camera cull traversals in parallel with

the previous frames draw traversal.  Changes range from osg::State, through osgUtil::RenderBin, through to osgViewer

include/osg/State

@@ -753,6 +753,47 @@ class OSG_EXPORT State : public Referenced
           * if true steps should be taken to complete rendering early.*/
         bool getAbortRendering() const { return _abortRenderingPtr!=0?(*_abortRenderingPtr):false; }
 
+
+        struct DynamicObjectRenderingCompletedCallback : public osg::Referenced
+        {
+            virtual void completed(osg::State*) = 0;
+        };
+        
+        /** Set the callback to be called when the dynamic object count hits 0.*/
+        void setDynamicObjectRenderingCompletedCallback(DynamicObjectRenderingCompletedCallback* cb){ _completeDynamicObjectRenderingCallback = cb; }
+        
+        /** Get the callback to be called when the dynamic object count hits 0.*/
+        DynamicObjectRenderingCompletedCallback* getDynamicObjectRenderingCompletedCallback() { return _completeDynamicObjectRenderingCallback.get(); }
+        
+        /** Set the number of dynamic objects that will be rendered in this graphics context this frame.*/
+        void setDynamicObjectCount(unsigned int count, bool callCallbackOnZero = false)
+        {
+            if (_dynamicObjectCount != count)
+            {
+                _dynamicObjectCount = count;
+                if (_dynamicObjectCount==0 && callCallbackOnZero && _completeDynamicObjectRenderingCallback.valid())
+                {
+                    _completeDynamicObjectRenderingCallback->completed(this);
+                }
+            }
+        }
+
+        /** Get the number of dynamic objects that will be rendered in this graphics context this frame.*/
+        unsigned int getDynamicObjectCount() const { return _dynamicObjectCount; }
+        
+        /** Decrement the number of dynamic objects left to render this frame, and once the count goes to zero call the 
+          * DynamicObjectRenderingCompletedCallback to inform of completion.*/
+        inline void decrementDynamicObjectCount()
+        {
+            --_dynamicObjectCount;
+            if (_dynamicObjectCount==0 && _completeDynamicObjectRenderingCallback.valid())
+            {
+                _completeDynamicObjectRenderingCallback->completed(this);
+            }
+        } 
+
+
+
         enum CheckForGLErrors
         {
             /** NEVER_CHECK_GL_ERRORS hints that OpenGL need not be checked for, this 
@@ -1028,6 +1069,9 @@ class OSG_EXPORT State : public Referenced
         DisableVertexAttribProc     _glDisableVertexAttribArray;
         void initializeExtensionProcs();
 
+        unsigned int                                            _dynamicObjectCount;
+        osg::ref_ptr<DynamicObjectRenderingCompletedCallback>   _completeDynamicObjectRenderingCallback;
+        
 };
 
 inline void State::pushModeList(ModeMap& modeMap,const StateSet::ModeList& modeList)

include/osgUtil/Optimizer

@@ -82,6 +82,7 @@ class OSGUTIL_EXPORT Optimizer
             MERGE_GEODES =              0x1000,
             FLATTEN_BILLBOARDS =        0x2000,
             TEXTURE_ATLAS_BUILDER =     0x4000,
+            STATIC_OBJECT_DETECTION =   0x8000,
             DEFAULT_OPTIMIZATIONS = FLATTEN_STATIC_TRANSFORMS |
                                 REMOVE_REDUNDANT_NODES |
                                 REMOVE_LOADED_PROXY_NODES |
@@ -89,7 +90,8 @@ class OSGUTIL_EXPORT Optimizer
                                 SHARE_DUPLICATE_STATE |
                                 MERGE_GEOMETRY |
                                 CHECK_GEOMETRY |
-                                OPTIMIZE_TEXTURE_SETTINGS,
+                                OPTIMIZE_TEXTURE_SETTINGS |
+                                STATIC_OBJECT_DETECTION,
             ALL_OPTIMIZATIONS = FLATTEN_STATIC_TRANSFORMS |
                                 REMOVE_REDUNDANT_NODES |
                                 REMOVE_LOADED_PROXY_NODES |
@@ -102,7 +104,8 @@ class OSGUTIL_EXPORT Optimizer
                                 COPY_SHARED_NODES |
                                 TRISTRIP_GEOMETRY |
                                 OPTIMIZE_TEXTURE_SETTINGS |
-                                TEXTURE_ATLAS_BUILDER
+                                TEXTURE_ATLAS_BUILDER |
+                                STATIC_OBJECT_DETECTION
         };
 
         /** Reset internal data to initial state - the getPermissibleOptionsMap is cleared.*/
@@ -740,6 +743,27 @@ class OSGUTIL_EXPORT Optimizer
 
         };
 
+        /** Optimize the setting of StateSet and Geometry objects in scene so that they have a STATIC DataVariance
+          * when they don't have any callbacks associated with them. */
+        class OSGUTIL_EXPORT StaticObjectDetectionVisitor : public BaseOptimizerVisitor
+        {
+            public:
+
+                /// default to traversing all children.
+                StaticObjectDetectionVisitor(Optimizer* optimizer=0):
+                    BaseOptimizerVisitor(optimizer, STATIC_OBJECT_DETECTION) {}
+
+                virtual void apply(osg::Node& node);
+
+                virtual void apply(osg::Geode& geode);
+
+            protected:
+
+                void applyStateSet(osg::StateSet& stateset);
+                
+                void applyDrawable(osg::Drawable& drawable);
+
+        };
 };
 
 inline bool BaseOptimizerVisitor::isOperationPermissibleForObject(const osg::StateSet* object) const

include/osgUtil/RenderBin

@@ -141,6 +141,9 @@ class OSGUTIL_EXPORT RenderBin : public osg::Object
         /** Extract stats for current draw list. */
         bool getStats(Statistics& primStats) const;
         
+        /** Compute the number of dynamic RenderLeaves.*/
+        virtual unsigned int computeNumberOfDynamicRenderLeaves() const;
+
         void copyLeavesFromStateGraphListToRenderLeafList();
 
     protected:

include/osgUtil/RenderLeaf

@@ -39,7 +39,10 @@ class OSGUTIL_EXPORT RenderLeaf : public osg::Referenced
             _drawable(drawable),
             _projection(projection),
             _modelview(modelview),
-            _depth(depth) {}
+            _depth(depth)
+        {
+            _dynamic = (drawable->getDataVariance()==osg::Object::DYNAMIC);
+        }
 
         
         inline void set(osg::Drawable* drawable,osg::RefMatrix* projection,osg::RefMatrix* modelview, float depth=0.0f)
@@ -49,6 +52,7 @@ class OSGUTIL_EXPORT RenderLeaf : public osg::Referenced
             _projection = projection,
             _modelview = modelview,
             _depth = depth;
+            _dynamic = (drawable->getDataVariance()==osg::Object::DYNAMIC);
         }
         
         inline void reset()
@@ -58,6 +62,7 @@ class OSGUTIL_EXPORT RenderLeaf : public osg::Referenced
             _projection = 0;
             _modelview = 0;
             _depth = 0.0f;
+            _dynamic = false;
         }
     
         virtual void render(osg::RenderInfo& renderInfo,RenderLeaf* previous);
@@ -72,6 +77,7 @@ class OSGUTIL_EXPORT RenderLeaf : public osg::Referenced
         osg::ref_ptr<osg::RefMatrix>    _projection;
         osg::ref_ptr<osg::RefMatrix>    _modelview;
         float                           _depth;
+        bool                            _dynamic;
 
     private:
 

include/osgUtil/RenderStage

@@ -201,7 +201,8 @@ class OSGUTIL_EXPORT RenderStage : public RenderBin
         /** Extract stats for current draw list. */
         bool getStats(Statistics& stats) const; 
  
-
+        /** Compute the number of dynamic RenderLeaves.*/
+        virtual unsigned int computeNumberOfDynamicRenderLeaves() const;
 
         struct Attachment
         {

include/osgUtil/StateGraph

@@ -58,6 +58,7 @@ class OSGUTIL_EXPORT StateGraph : public osg::Referenced
         
         osg::ref_ptr<osg::Referenced>       _userData;
 
+        bool                                _dynamic;
 
         StateGraph():
             osg::Referenced(false),
@@ -66,7 +67,8 @@ class OSGUTIL_EXPORT StateGraph : public osg::Referenced
             _depth(0),
             _averageDistance(0),
             _minimumDistance(0),
-            _userData(NULL)
+            _userData(NULL),
+            _dynamic(false)
         {
         }
 
@@ -77,9 +79,13 @@ class OSGUTIL_EXPORT StateGraph : public osg::Referenced
             _depth(0),
             _averageDistance(0),
             _minimumDistance(0),
-            _userData(NULL)
+            _userData(NULL),
+            _dynamic(false)
         {
             if (_parent) _depth = _parent->_depth + 1;
+            
+            if (_parent && _parent->_dynamic) _dynamic = true;
+            else _dynamic = stateset->getDataVariance()==osg::Object::DYNAMIC;
         }
             
         ~StateGraph() {}
@@ -176,6 +182,7 @@ class OSGUTIL_EXPORT StateGraph : public osg::Referenced
                 _minimumDistance = FLT_MAX; // signify dirty.
                 _leaves.push_back(leaf);
                 leaf->_parent = this;
+                if (_dynamic) leaf->_dynamic = true;
             }
         }
 

include/osgViewer/View

@@ -25,6 +25,30 @@
 
 namespace osgViewer {
 
+class OSGVIEWER_EXPORT EndOfDynamicDrawBlock : public osg::State::DynamicObjectRenderingCompletedCallback
+{
+    public:
+    
+        EndOfDynamicDrawBlock();
+    
+        void completed(osg::State* state);
+
+        void block();
+
+        void release();
+
+        void set(unsigned int blockCount);
+
+    protected:
+
+        ~EndOfDynamicDrawBlock();
+
+        OpenThreads::Mutex _mut;
+        OpenThreads::Condition _cond;
+        unsigned int _blockCount;
+};
+
+
 /** View holds a single view on a scene, this view may be composed of one or more slave cameras.*/
 class OSGVIEWER_EXPORT View : public osg::View, public osgGA::GUIActionAdapter
 {

include/osgViewer/Viewer

@@ -63,6 +63,13 @@ class OSGVIEWER_EXPORT Viewer : public osgViewer::View
         /** Get the threading model the rendering traversals will use.*/
         ThreadingModel getThreadingModel() const { return _threadingModel; }
 
+        /** Set whether the main thread, calling frame(), should be used for the rendering traversals.*/
+        void setUseMainThreadForRenderingTraversals(bool flag);
+        
+        /** Get whether the main thread, calling frame(), should be used for the rendering traversals.*/
+        bool getUseMainThreadForRenderingTraversals() const { return _useMainThreadForRenderingTraversal; }
+
+
         enum BarrierPosition
         {
             BeforeSwapBuffers,
@@ -149,10 +156,12 @@ class OSGVIEWER_EXPORT Viewer : public osgViewer::View
         bool _quitEventSetsDone;
         
         ThreadingModel  _threadingModel;
+        bool            _useMainThreadForRenderingTraversal;
         BarrierPosition _endBarrierPosition;
 
         osg::ref_ptr<osg::BarrierOperation> _startRenderingBarrier;
         osg::ref_ptr<osg::BarrierOperation> _endRenderingDispatchBarrier;
+        osg::ref_ptr<EndOfDynamicDrawBlock> _endDynamicDrawBlock;
 
         unsigned int computeNumberOfThreadsIncludingMainRequired();
 

src/osg/Drawable.cpp

@@ -246,6 +246,8 @@ void Drawable::flushDeletedVertexBufferObjects(unsigned int contextID,double /*c
 
 Drawable::Drawable()
 {
+    setDataVariance(osg::Object::STATIC);
+
     _boundingBoxComputed = false;
 
     // Note, if your are defining a subclass from drawable which is

src/osg/State.cpp

@@ -53,6 +53,8 @@ State::State()
     _glVertexAttribPointer = 0;
     _glEnableVertexAttribArray = 0;
     _glDisableVertexAttribArray = 0;
+
+    _dynamicObjectCount  = 0;
 }
 
 State::~State()

src/osg/StateSet.cpp

@@ -80,7 +80,7 @@ bool osg::isTextureMode(StateAttribute::GLMode mode)
 
 StateSet::StateSet()
 {
-    setDataVariance(osg::StateAttribute::STATIC);
+    setDataVariance(osg::Object::STATIC);
 
     _renderingHint = DEFAULT_BIN;
     

src/osgUtil/Optimizer.cpp

@@ -47,7 +47,7 @@ void Optimizer::reset()
 {
 }
 
-static osg::ApplicationUsageProxy Optimizer_e0(osg::ApplicationUsage::ENVIRONMENTAL_VARIABLE,"OSG_OPTIMIZER \"<type> [<type>]\"","OFF | DEFAULT | FLATTEN_STATIC_TRANSFORMS | REMOVE_REDUNDANT_NODES | COMBINE_ADJACENT_LODS | SHARE_DUPLICATE_STATE | MERGE_GEOMETRY | MERGE_GEODES | SPATIALIZE_GROUPS  | COPY_SHARED_NODES  | TRISTRIP_GEOMETRY | OPTIMIZE_TEXTURE_SETTINGS | REMOVE_LOADED_PROXY_NODES | TESSELLATE_GEOMETRY | CHECK_GEOMETRY |  FLATTEN_BILLBOARDS | TEXTURE_ATLAS_BUILDER");
+static osg::ApplicationUsageProxy Optimizer_e0(osg::ApplicationUsage::ENVIRONMENTAL_VARIABLE,"OSG_OPTIMIZER \"<type> [<type>]\"","OFF | DEFAULT | FLATTEN_STATIC_TRANSFORMS | REMOVE_REDUNDANT_NODES | COMBINE_ADJACENT_LODS | SHARE_DUPLICATE_STATE | MERGE_GEOMETRY | MERGE_GEODES | SPATIALIZE_GROUPS  | COPY_SHARED_NODES  | TRISTRIP_GEOMETRY | OPTIMIZE_TEXTURE_SETTINGS | REMOVE_LOADED_PROXY_NODES | TESSELLATE_GEOMETRY | CHECK_GEOMETRY |  FLATTEN_BILLBOARDS | TEXTURE_ATLAS_BUILDER | STATIC_OBJECT_DETECTION");
 
 void Optimizer::optimize(osg::Node* node)
 {
@@ -109,6 +109,9 @@ void Optimizer::optimize(osg::Node* node)
         if(str.find("~TEXTURE_ATLAS_BUILDER")!=std::string::npos) options ^= TEXTURE_ATLAS_BUILDER;
         else if(str.find("TEXTURE_ATLAS_BUILDER")!=std::string::npos) options |= TEXTURE_ATLAS_BUILDER;
         
+        if(str.find("~STATIC_OBJECT_DETECTION")!=std::string::npos) options ^= STATIC_OBJECT_DETECTION;
+        else if(str.find("STATIC_OBJECT_DETECTION")!=std::string::npos) options |= STATIC_OBJECT_DETECTION;
+
     }
     else
     {
@@ -300,6 +303,12 @@ void Optimizer::optimize(osg::Node* node, unsigned int options)
         sv.divide();
     }
 
+    if (options & STATIC_OBJECT_DETECTION)
+    {
+        StaticObjectDetectionVisitor sodv;
+        node->accept(sodv);
+    }
+
     if (osg::getNotifyLevel()>=osg::INFO)
     {
         stats.reset();
@@ -4104,3 +4113,45 @@ void Optimizer::TextureAtlasVisitor::optimize()
     }
 }
 
+
+
+
+////////////////////////////////////////////////////////////////////////////
+// StaticObjectDectionVisitor
+////////////////////////////////////////////////////////////////////////////
+
+void Optimizer::StaticObjectDetectionVisitor::apply(osg::Node& node)
+{
+    if (node.getStateSet()) applyStateSet(*node.getStateSet());
+
+    traverse(node);
+}
+
+void Optimizer::StaticObjectDetectionVisitor::apply(osg::Geode& geode)
+{
+    if (geode.getStateSet()) applyStateSet(*geode.getStateSet());
+
+    for(unsigned int i=0; i<geode.getNumDrawables(); ++i)
+    {
+        applyDrawable(*geode.getDrawable(i));
+    }
+}
+
+void Optimizer::StaticObjectDetectionVisitor::applyStateSet(osg::StateSet& stateset)
+{
+    stateset.setDataVariance(osg::Object::STATIC);
+}
+
+
+void Optimizer::StaticObjectDetectionVisitor::applyDrawable(osg::Drawable& drawable)
+{
+    if (drawable.getStateSet()) applyStateSet(*drawable.getStateSet());
+
+    osg::Object::DataVariance dataVariance = osg::Object::STATIC;
+    
+    if (drawable.getDrawCallback()) dataVariance = osg::Object::DYNAMIC;
+    if (drawable.getCullCallback()) dataVariance = osg::Object::DYNAMIC;
+    if (drawable.getDrawCallback()) dataVariance = osg::Object::DYNAMIC;
+    
+    drawable.setDataVariance(dataVariance);
+}

src/osgUtil/RenderBin.cpp

@@ -301,7 +301,7 @@ void RenderBin::sortBackToFront()
 
 void RenderBin::copyLeavesFromStateGraphListToRenderLeafList()
 {
-    // _renderLeafList.clear();
+    _renderLeafList.clear();
 
     int totalsize=0;
     StateGraphList::iterator itr;
@@ -509,3 +509,52 @@ bool RenderBin::getStats(Statistics& stats) const
 
     return statsCollected;
 }
+
+unsigned int RenderBin::computeNumberOfDynamicRenderLeaves() const
+{
+    unsigned int count = 0;
+
+    // draw first set of draw bins.
+    RenderBinList::const_iterator rbitr;
+    for(rbitr = _bins.begin();
+        rbitr!=_bins.end() && rbitr->first<0;
+        ++rbitr)
+    {
+        count += rbitr->second->computeNumberOfDynamicRenderLeaves();
+    }
+
+    // draw fine grained ordering.
+    for(RenderLeafList::const_iterator rlitr= _renderLeafList.begin();
+        rlitr!= _renderLeafList.end();
+        ++rlitr)
+    {
+        RenderLeaf* rl = *rlitr;
+        if (rl->_dynamic) ++count;
+    }
+
+
+    // draw coarse grained ordering.
+    for(StateGraphList::const_iterator oitr=_stateGraphList.begin();
+        oitr!=_stateGraphList.end();
+        ++oitr)
+    {
+
+        for(StateGraph::LeafList::const_iterator dw_itr = (*oitr)->_leaves.begin();
+            dw_itr != (*oitr)->_leaves.end();
+            ++dw_itr)
+        {
+            RenderLeaf* rl = dw_itr->get();
+            if (rl->_dynamic) ++count;
+        }
+    }
+
+    // draw post bins.
+    for(;
+        rbitr!=_bins.end();
+        ++rbitr)
+    {
+        count += rbitr->second->computeNumberOfDynamicRenderLeaves();
+    }
+    
+    return count;
+}

src/osgUtil/RenderLeaf.cpp

@@ -74,5 +74,10 @@ void RenderLeaf::render(osg::RenderInfo& renderInfo,RenderLeaf* previous)
         _drawable->draw(renderInfo);
     }
     
+    if (_dynamic)
+    {
+        state.decrementDynamicObjectCount();
+    }
+    
     // osg::notify(osg::NOTICE)<<"RenderLeaf "<<_drawable->getName()<<" "<<_depth<<std::endl;
 }

src/osgUtil/RenderStage.cpp

@@ -1031,3 +1031,27 @@ void RenderStage::attach(osg::Camera::BufferComponent buffer, osg::Image* image)
 {
     _bufferAttachmentMap[buffer]._image = image;
 }
+
+unsigned int RenderStage::computeNumberOfDynamicRenderLeaves() const
+{
+    unsigned int count = 0;
+
+    for(RenderStageList::const_iterator pre_itr = _preRenderList.begin();
+        pre_itr != _preRenderList.end();
+        ++pre_itr)
+    {
+        count += pre_itr->second->computeNumberOfDynamicRenderLeaves();
+    }
+
+    count += RenderBin::computeNumberOfDynamicRenderLeaves();
+
+    for(RenderStageList::const_iterator post_itr = _postRenderList.begin();
+        post_itr != _postRenderList.end();
+        ++post_itr)
+    {
+        count += post_itr->second->computeNumberOfDynamicRenderLeaves();
+    }
+    
+    return count;
+}
+

src/osgUtil/SceneView.cpp

@@ -777,6 +777,11 @@ void SceneView::cullStage(const osg::Matrixd& projection,const osg::Matrixd& mod
     // a clean has been used instead to try to minimize the amount of
     // allocation and deleteing of the StateGraph nodes.
     rendergraph->prune();
+    
+    // set the number of dynamic objects in the scene.    
+    getState()->setDynamicObjectCount( getState()->getDynamicObjectCount() + renderStage->computeNumberOfDynamicRenderLeaves());
+
+    // osg::notify(osg::NOTICE)<<"SceneView  cull() DynamicObjectCount"<<getState()->getDynamicObjectCount()<<std::endl;
 }
 
 void SceneView::releaseAllGLObjects()
@@ -1319,6 +1324,9 @@ void SceneView::draw()
             state->setCheckForGLErrors(osg::State::ONCE_PER_ATTRIBUTE);
         }
     }
+
+    // osg::notify(osg::NOTICE)<<"SceneView  draw() DynamicObjectCount"<<getState()->getDynamicObjectCount()<<std::endl;
+
 }
 
 /** Calculate, via glUnProject, the object coordinates of a window point.

src/osgViewer/View.cpp

@@ -522,3 +522,60 @@ bool View::computeIntersections(float x,float y, osg::NodePath& nodePath, osgUti
         return false;
     }
 }
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// EndOfDynamicDrawBlock
+//
+EndOfDynamicDrawBlock::EndOfDynamicDrawBlock():
+    _blockCount(0)
+{
+}
+
+void EndOfDynamicDrawBlock::completed(osg::State* state)
+{
+    OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
+    if (_blockCount>0)
+    {
+        --_blockCount;
+
+        if (_blockCount==0)
+        {
+            // osg::notify(osg::NOTICE)<<"Released"<<std::endl;
+            _cond.broadcast();
+        }
+    }
+}
+
+void EndOfDynamicDrawBlock::block()
+{
+    OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
+    if (_blockCount)
+        _cond.wait(&_mut);
+}
+
+void EndOfDynamicDrawBlock::release()
+{
+    OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
+    if (_blockCount)
+    {
+        _blockCount = 0;
+        _cond.broadcast();
+    }
+}
+
+void EndOfDynamicDrawBlock::set(unsigned int blockCount)
+{
+    OpenThreads::ScopedLock<OpenThreads::Mutex> mutlock(_mut);
+    if (blockCount!=_blockCount)
+    {
+        if (blockCount==0) _cond.broadcast();
+        _blockCount = blockCount;
+    }
+}
+
+EndOfDynamicDrawBlock::~EndOfDynamicDrawBlock()
+{
+    release();
+}

src/osgViewer/Viewer.cpp

@@ -170,6 +170,16 @@ void Viewer::setThreadingModel(ThreadingModel threadingModel)
     if (_threadingModel!=SingleThreaded) startThreading();
 }
 
+void Viewer::setUseMainThreadForRenderingTraversals(bool flag)
+{
+    if (_useMainThreadForRenderingTraversal==flag) return;
+
+    if (_threadingModel!=SingleThreaded) stopThreading();
+    
+    _useMainThreadForRenderingTraversal = flag;
+    
+    if (_threadingModel!=SingleThreaded) startThreading();
+}
 
 void Viewer::setEndBarrierPosition(BarrierPosition bp)
 {
@@ -259,12 +269,9 @@ unsigned int Viewer::computeNumberOfThreadsIncludingMainRequired()
         return 1;
     }
 
-    bool firstContextAsMainThread = _threadingModel == ThreadPerContext;
+    return _useMainThreadForRenderingTraversal ? contexts.size() : contexts.size()+1;
-    
-    return firstContextAsMainThread ? contexts.size() : contexts.size()+1;
 }
 
-
 void Viewer::startThreading()
 {
     unsigned int numThreadsIncludingMainThread = computeNumberOfThreadsIncludingMainRequired();
@@ -310,11 +317,21 @@ void Viewer::startThreading()
 
     _numThreadsOnBarrier = numThreadsIncludingMainThread;
     _startRenderingBarrier = new osg::BarrierOperation(_numThreadsOnBarrier, osg::BarrierOperation::NO_OPERATION);
+
+
+    if (_threadingModel==ThreadPerContext)
+    {
     #if 1
         _endRenderingDispatchBarrier = new osg::BarrierOperation(_numThreadsOnBarrier, osg::BarrierOperation::NO_OPERATION);
     #else    
         _endRenderingDispatchBarrier = new osg::BarrierOperation(_numThreadsOnBarrier, osg::BarrierOperation::GL_FINISH);
     #endif
+    }
+    else
+    {
+        _endDynamicDrawBlock = new EndOfDynamicDrawBlock;
+    }
+
     osg::ref_ptr<osg::SwapBuffersOperation> swapOp = new osg::SwapBuffersOperation();
 
     Contexts::iterator citr = contexts.begin(); 
@@ -326,6 +343,7 @@ void Viewer::startThreading()
         ++citr;
     }
 
+
     for(;
         citr != contexts.end();
         ++citr,
@@ -333,6 +351,8 @@ void Viewer::startThreading()
     {
         osg::GraphicsContext* gc = (*citr);
         
+        gc->getState()->setDynamicObjectRenderingCompletedCallback(_endDynamicDrawBlock.get());
+
         // create the a graphics thread for this context
         gc->createGraphicsThread();
 
@@ -346,7 +366,7 @@ void Viewer::startThreading()
         // add the rendering operation itself.
         gc->getGraphicsThread()->add(new ViewerRunOperations());
 
-        if (_endBarrierPosition==BeforeSwapBuffers)
+        if (_endBarrierPosition==BeforeSwapBuffers && _endRenderingDispatchBarrier.valid())
         {
             // add the endRenderingDispatchBarrier
             gc->getGraphicsThread()->add(_endRenderingDispatchBarrier.get());
@@ -355,7 +375,7 @@ void Viewer::startThreading()
         // add the swap buffers
         gc->getGraphicsThread()->add(swapOp.get());
 
-        if (_endBarrierPosition==AfterSwapBuffers)
+        if (_endBarrierPosition==AfterSwapBuffers && _endRenderingDispatchBarrier.valid())
         {
             // add the endRenderingDispatchBarrier
             gc->getGraphicsThread()->add(_endRenderingDispatchBarrier.get());
@@ -561,6 +581,10 @@ struct ViewerRenderingOperation : public osg::GraphicsOperation
         _sceneView->cull();
         osg::Timer_t afterCullTick = osg::Timer::instance()->tick();
 
+        if (state->getDynamicObjectCount()==0 && state->getDynamicObjectRenderingCompletedCallback())
+        {
+            state->getDynamicObjectRenderingCompletedCallback()->completed(state);
+        }
 
         // do draw traveral
         if (_aquireGPUStats) 
@@ -1188,10 +1212,23 @@ void Viewer::renderingTraversals()
     Contexts contexts;
     getContexts(contexts);
     
+    Contexts::iterator itr;
+    if (_endDynamicDrawBlock.valid())
+    {
+        unsigned int numToBlock = 0;
+        for(itr = contexts.begin();
+            itr != contexts.end();
+            ++itr)
+        {
+            if (((*itr)->getGraphicsThread())) ++numToBlock;
+        }
+
+        _endDynamicDrawBlock->set(numToBlock);
+    }
+
     // dispatch the the rendering threads
     if (_startRenderingBarrier.valid()) _startRenderingBarrier->block();
 
-    Contexts::iterator itr;
     for(itr = contexts.begin();
         itr != contexts.end();
         ++itr)
@@ -1207,6 +1244,14 @@ void Viewer::renderingTraversals()
 
     // osg::notify(osg::NOTICE)<<"Joing _endRenderingDispatchBarrier block"<<std::endl;
 
+    // wait till the dynamic draw is complete.
+    if (_endDynamicDrawBlock.valid()) 
+    {
+        // osg::Timer_t startTick = osg::Timer::instance()->tick();
+        _endDynamicDrawBlock->block();
+        // osg::notify(osg::NOTICE)<<"Time waiting "<<osg::Timer::instance()->delta_m(startTick, osg::Timer::instance()->tick())<<std::endl;;
+    }
+
     // wait till the rendering dispatch is done.
     if (_endRenderingDispatchBarrier.valid()) _endRenderingDispatchBarrier->block();