I think this is necessary on OpenGL 3.2+ since this is no more "default" locations in the OpenGL specs.
The default behaviour stay the same.
There is a few new methods on osg::State :
- resetVertexAttributeAlias : reset all vertex alias to osg's default ones
- set**Alias : set a vertex attribute alias configuration
- setAttributeBindingList : set the attribute binding list (allow to specify an empty list if you're using "layout" qualifier in glsl code to specify the bindings. This save some CPU operations)"