OSG Note

1. osg::NodePath 在include/osg/Node中定义，

/** A vector of Nodes pointers which is used to describe the path from a root node to a descendant(后裔).*/
typedef std::vector< Node* > NodePath;

2. osg::StateSet::setBinNumber(int num);//设置osg渲染的顺序，该顺序与深度测试无关，只关乎场景对象的渲染次序。

3.osg::StateSet::setRenderHint(int Hint);//Hint为一个枚举值：StateSet::OPAQUE_BIN 、 StateSet::TRANSPARENT_BIN.