The structure of a scene graph in memory

The typical structure of a scene graph in memory

osg::Group at the top containing the whole graph

osg::Groups, LOD's, Transform, Switches in the middle

osg::Geode/Billboard Nodes are the leaf nodes which contain...

osg::Drawables which are leaves that contain the geometry and can be drawn.

osg::StateSets attached to Nodes and Drawables, state inherits from parents only.