void CullVisitor::apply(Geode& node)
{
    if (isCulled(node)) return;

    // push the node's state.
    StateSet* node_state = node.getStateSet();
    if (node_state) pushStateSet(node_state);

    // traverse any call callbacks and traverse any children.
    handle_cull_callbacks_and_traverse(node);

    RefMatrix& matrix = *getModelViewMatrix();
    for(unsigned int i=0;i<node.getNumDrawables();++i)
    {
        Drawable* drawable = node.getDrawable(i);
        const BoundingBox &bb =drawable->getBound();

        if( drawable->getCullCallback() )
        {
            if( drawable->getCullCallback()->cull( this, drawable, &_renderInfo ) == true )
            continue;
        }
        
        //else
        {
            if (node.isCullingActive() && isCulled(bb)) continue;
        }


        if (_computeNearFar && bb.valid()) 
        {
            if (!updateCalculatedNearFar(matrix,*drawable,false)) continue;
        }

        // need to track how push/pops there are, so we can unravel the stack correctly.
        unsigned int numPopStateSetRequired = 0;

        // push the geoset's state on the geostate stack.    
        StateSet* stateset = drawable->getStateSet();
        if (stateset)
        {
            ++numPopStateSetRequired;
            pushStateSet(stateset);
        }

        CullingSet& cs = getCurrentCullingSet();
        if (!cs.getStateFrustumList().empty())
        {
            osg::CullingSet::StateFrustumList& sfl = cs.getStateFrustumList();
            for(osg::CullingSet::StateFrustumList::iterator itr = sfl.begin();
                itr != sfl.end();
                ++itr)
            {
                if (itr->second.contains(bb))
                {
                    ++numPopStateSetRequired;
                    pushStateSet(itr->first.get());
                }
            }
        }

        float depth = bb.valid() ? distance(bb.center(),matrix) : 0.0f;
        
        if (osg::isNaN(depth))
        {
            OSG_NOTICE<<"CullVisitor::apply(Geode&) detected NaN,"<<std::endl
                                    <<"    depth="<<depth<<", center=("<<bb.center()<<"),"<<std::endl
                                    <<"    matrix="<<matrix<<std::endl;
            OSG_DEBUG << "    NodePath:" << std::endl;
            for (NodePath::const_iterator i = getNodePath().begin(); i != getNodePath().end(); ++i)
            {
                OSG_DEBUG << "        \"" << (*i)->getName() << "\"" << std::endl;
            }
        }
        else
        {        
            addDrawableAndDepth(drawable,&matrix,depth);
        }

        for(unsigned int i=0;i< numPopStateSetRequired; ++i)
        {
            popStateSet();
        }

    }

    // pop the node's state off the geostate stack.    
    if (node_state) popStateSet();

}