pushStateSet(const osg::StateSet* ss)建立渲染叶

        inline void pushStateSet(const osg::StateSet* ss)
        {
            _currentStateGraph = _currentStateGraph->find_or_insert(ss);//

            if (_numberOfEncloseOverrideRenderBinDetails==0 && ss->useRenderBinDetails() && !ss->getBinName().empty())
            {
                   _renderBinStack.push_back(_currentRenderBin);//+

                    _currentRenderBin = ss->getNestRenderBins() ?
                    _currentRenderBin->find_or_insert(ss->getBinNumber(),ss->getBinName()) ://在透明的情况下使用
                    _currentRenderBin->getStage()->find_or_insert(ss->getBinNumber(),ss->getBinName());//当前渲染台

                   //_currentRenderBin指向当前的自己,_statege = this;
            }

            if (ss->getRenderBinMode()==osg::StateSet::OVERRIDE_RENDERBIN_DETAILS)
            {
                ++_numberOfEncloseOverrideRenderBinDetails;
            }
        }